ASUS Z97-A Mainboard Review: New Look of LGA 1150 Platform

ASUS’s new mainboard looks improved with its updated BIOS and modern interfaces. But are all of those improvements really good? And what exactly is the difference between it and the older models? We’ll find the answers right now in this review

by Doors4ever
07/02/2014 | 07:05 PM

In the first half of May, Intel carried out a global update of the LGA1150 platform. You may have learned about Intel’s new processors from our Haswell Refresh review. They are actually the same Haswell-based products but have a 100MHz higher clock rate, so their performance and model numbers have got slightly higher. Although there’s nothing fundamentally new about the Haswell Refresh series, they come at the same price as their predecessors, giving us no reason to feel particularly disappointed. It’s always good to have even minor improvements if you are not asked to pay for them.

 

Besides processors, the selection of chipsets was refreshed as well. Most of Intel’s 8 series chipsets, including the H81, B85, Q85 and Q87, were left as they were but the two senior ones, Z87 and H87, have got enhanced versions that go under the names of Z97 and H97. Comparing the Z87 with the new Z97, we won’t find many differences, the most conspicuous of which is the support for the upcoming fifth-generation Core processors.

Considering the similar chipsets, we might expect new mainboards to be hardly different from older ones. Z97 and H97-based mainboards are already selling and some of them are indeed exactly as their predecessors, yet there are quite a lot of absolutely new models, too. The support for new processors is good but we still have to wait for those processors to come out. Right now, the enhanced storage capabilities of the new chipsets, which are not reflected in the schematics, turn out to be more important. The new mainboards feature faster PCIe-based interfaces for the storage subsystem: M.2 and SATA Express. These were occasionally implemented in the past (for example some of ASUS’s ROG series products had an M.2 connector) but the implementation is much easier with the new chipsets.

To check out the refreshed LGA1150 platform we’ve picked up the ASUS Z97-A mainboard because it is a midrange model. It is not too simple, yet also not too overloaded with extra features and controllers. We’ll cover flagship and, perhaps, entry-level models in the future.

Being the major mainboard manufacturer, ASUS has a reputation to maintain, so they can’t afford to release an unfinished product. We can expect the Z97-A to have a user-friendly PCB design and adequate functionality without any obvious defects. Now let’s get started.

Packaging and Accessories

A new chipset is not a strong enough reason to change anything in product packaging. So, like with other ASUS mainboards, the front of the box shows the model name and logotypes. The product’s specifications and key features are listed on the back.

The mainboard is wrapped into an antistatic pack inside. Below it, under a sheet of cardboard, you will find the following accessories:

There’s nothing unusual about the accessories except for the odd number of SATA cables. Such cables are even packed in pairs, so you usually get an even number of them.

PCB Design and Features

We’d never guess the Z97-A is just a midrange model by its looks. Its appearance is quite impressive. The 8-phase digital power system DIGI+ supports both existing and upcoming LGA1150 processors. Its hot components are cooled with a couple of heatsinks. The chipset heatsink is fastened with screws whereas the two additional heatsinks are secured with spring-loaded plastic pins. They never get too hot, though, even when the mainboard is overclocked. The four memory slots can take in up to 32 gigabytes of DDR3 SDRAM clocked at frequencies up to 3200 MHz.

There are four SATA 6 Gbit/s ports and a new SATA Express connector in the right part of the PCB. If you don't have a SATA Express drive, you can use the connector as two SATA 6 Gbit/s ports, so the total number of SATA ports is six.

Below the CPU socket, there’s an M.2 connector with support for drives with a width of 22 mm and a length of 60 or 80 mm. It is disabled by default because it shares PCIe lanes with the two PCIe 2.0 x1 expansion slots. So, owners of the Z97-A don’t have to wait for SATA Express SSDs to come out. They can use M.2 drives which are already available. You can get more information about these new connectors and compatible SSDs from our Plextor M6e PCIe drive review.

The problem is that the specification describes an M.2 slot as having four PCIe lanes and one SATA port. However, Intel chipsets don't have enough of free PCIe lanes, so the SATA Express and M.2 connectors have only two rather than four PCIe lanes. Moreover, the ASUS Z97-A isn’t a flagship model and has no additional controllers. Four of the chipset's SATA ports are implemented as SATA connectors on it. Two more ports are in the SATA Express connector. So the M.2 connector ends up with no SATA interface at all. If you look into the mainboard’s specs, you can find out that its M.2 connector only supports PCI Express drives. It turns out that the Z97-A is only compatible with such rare SSDs as the Plextor M6e in M.2 form-factor but cannot work with the majority of existing SATA-based M.2 drives.

The two PCIe 3.0/2.0 x16 slots can share the processor’s PCIe lanes and let you build SLI or CrossFireX configurations. In the latter case you can throw in a third graphics card by installing it into the PCIe 2.0 x16 slot based on the chipset’s PCIe lanes. That third slot always works at x2 speed, though. Besides the mentioned slots, the mainboard offers two PCIe 2.0 x1 and two PCI slots for expansion cards.

The mainboard’s back panel is densely populated:

The mainboard's schematic shows a few additional features. There are six 4-pin fan connectors, two of which are for a CPU cooler. All of them can regulate both 4- and 3-pin fans. A connector for an additional temperature sensor can also be found in the schematic. The MemOK! button helps the mainboard start up in case of some memory-related problems. Besides the two familiar switches TPU (TurboV Processing Unit) and EPU (Energy Processing Unit), which overclock the computer and enable power-saving mode, respectively, there is a new switch called EZ XMP. It activates memory modules’ overclocking profile. As for the audio subsystem, the Crystal Sound 2 technology means a built-in amplifier, premium capacitors, EMI shielding and separate PCB layers for the left and right channels. The ASUS Z97-A doesn’t support USB BIOS Flashback although this technology might come in handy for the upcoming fifth-generation Core processors.

The mainboard supports Q-Design technologies which are meant to simplify the process of building and running an ASUS-based computer. You can quickly and easily identify the source of any boot-related problems by looking at the Q-LED indicators (CPU, DRAM, VGA and Boot Device LEDs). Then, we have broad graphics slot latches (Q-Slot), single-sided memory slot latches (Q-DIMM), and a set of adapters for connecting the mainboard to a computer case’s buttons, indicators and USB 2.0 connector (Q-Connector). The 5X Protection technology covers a number of engineering solutions that make the mainboard more reliable and long-lasting such as protection against overloads, short circuits and electrostatic discharges. The digital voltage regulator DIGI+ delivers stable power while the solid-state capacitors and the steel I/O Shield coated with a thin layer of chromium oxide (to prevent corrosion) increase the service life of the mainboard. And, finally, the 5-Way Optimization technology combines ASUS's exclusive features (TPU, EPU, DIGI+ Power Control, Fan Xpert 3 and Turbo App) which can help you optimize your computer for higher performance, power savings or energy efficiency.

We have summed up the basic specs of the ASUS Z97-A in the following table:

BIOS Capabilities

You may find the new UEFI BIOS interface odd-looking if you’ve had some previous experience with ASUS mainboards. As before, the BIOS opens in EZ Mode by default but the latter looks differently and offers much more capabilities than in the earlier BIOS interface.  You can set up date and time, change the interface language, learn some basic information about your computer, and load default settings. Then, you can set up your system memory, drives, fans, general operation mode (EZ System Tuning), and boot device order. EZ Mode used to be kind of useless, but it is not such anymore. Of course, it is not meant for complete system set-up. You need to switch to Advanced Mode for that. EZ Mode suffices well enough for initial setting-up, though.

There’s more animation in the screen. The CPU temperature graph is being updated regularly while the icons of operating fans are rotating. You can easily choose the operation mode for your fans from three predefined ones: Standard, Silent and Turbo. You can also set the fans at their maximum speed or regulate them manually by simply moving the dots in the graph. This Q-Fan Tuning feature can be later evoked by pressing the F6 key.

Are you a beginner user confused about all those abbreviations and technical terms? Then launch EZ Tuning Wizard that will guide you through a multistep process of overclocking your computer.

Using the same wizard, you can combine multiple drives into a RAID array.

If you’re an experienced user who doesn’t want any tips and advice, just switch from EZ to Advanced Mode by pressing the F7 key. You can later make the BIOS open up in Advanced Mode by default. Here, you can see the Main section which is familiar to us in its name and setup options but has a completely different interface. This section helps appreciate the highs and lows of the new interface, by the way. You can compare it to the same BIOS page from any older ASUS mainboard, for example from the ASUS Z87-K model. We won't dwell on the new fonts and visual theme because that's a matter of personal taste. The main thing is the structure of the BIOS page.

Active hotkeys used to be listed in the bottom right corner. The list is now a line at the top of the page. The new menu lets you set up date and time, change the interface language and proceed to the frequently accessed features, namely the list of My Favorites options (F3), Q-Fan Control (F6), and EZ Tuning Wizard (F11). The Quick Note option (F9) can be used to write down some important notes for yourself while the older list of active hotkeys is now concealed behind an intuitive question-mark icon (as always, you can evoke it by pressing the F1 key).

In the previous BIOS interface, when a BIOS option was selected, related information about its purpose, range and adjustment step was displayed in the column on the right. Now this area is reserved for monitoring information about clock rates, temperatures and voltages while the reference information is displayed lower. So the biggest downside of the new interface is that our view is smaller vertically because there’s the new hotkey line at the top and the Last Modified option (which lacks a hotkey) with the F7 link (to return to EZ Mode) at the bottom. Of course, our view has become broader horizontally but that was hardly a problem with the previous BIOS interface.

The Main section still reports basic system information and allows you set up date and time. You can also change the language for the BIOS interface to use and enter user and admin passwords in the Security subsection. However, even this small section doesn't fit fully into a single screen. The Security subsection is not visible by default anymore. You need to use your mouse wheel or arrow keys to access it but the scrollbar has been redesigned into an inconspicuous element with no arrow icons. If you don’t know beforehand, you can hardly guess that you don’t see all of the section options by default. Some users will just miss the Security subsection altogether and will never know it is there. And we have the same problem with the bigger BIOS sections. The small viewport makes it too easy for you to miss one or an entire group of options while scrolling through a BIOS page. 

The Main section is not the first on the list, though. It is preceded by My Favorites which helps collect frequently used BIOS options in one place. Empty by default, it suggests that you press F3 and select what options you want to save from a list of BIOS sections. There used to be some limitations about what options you could save, but not anymore. Still, the My Favorites section (like any other section for that matter) cannot be set as the start screen, which looks like a limitation to us.

Most of the overclocking-related options are collected in the Ai Tweaker section. It contains an enormous number of adjustable parameters and you don’t even see all of them by default because they are set up by the mainboard automatically. You will find a lot of previously hidden options as soon as you get down to manual setting-up.

For example, additional parameters appear as soon as you set the Ai Overclock Tuner option at X.M.P. (to automatically set up your memory subsystem parameters) or Manual. Some of the setup options are available in individual subsections in order not to clutter the main section. There is a separate page for memory timings with lots of options. Using the scrollbar, you can see all the timings set up by the mainboard for the two memory channels. You can adjust just some of them, leaving the others at their defaults.

There’s a separate BIOS subsection related to the digital power system called DIGI+. You can control ASUS’s exclusive power-saving technologies there, one of which allows changing the number of active phases in the CPU voltage regulator depending on load. CPU Load Line Calibration can now be not only enabled or disabled but also set to a certain level (it helps counteract the voltage drop occurring on the CPU under load).

ASUS mainboards offer a lot of Internal CPU Power Management options with some exclusive technologies. You can set up a number of parameters of the CPU-integrated voltage regulator to increase the response time and lower the power consumption in idle mode.

The voltages of the Ai Tweaker section can be set higher or lower than the default level. The current values are conveniently shown right next to the adjustment options. The CPU voltage can now be changed in three different ways: by fixing it at a certain level, by adding or subtracting a certain value (offset mode) and in adaptive mode. The Ai Tweaker section ends here but we still haven’t found a group of very important settings that control CPU power-saving technologies. Well, that’s a typical downside of many mainboards from many brands because all of them use AMI BIOS for their UEFI BIOS implementations. And AMI BIOS has a few questionable layout solutions.

The options of the Advanced section should be familiar to you and their names are self-descriptive. They are related to the chipset and additional controllers. You can also enable Intel Rapid Start and Intel Smart Connect here.

The CPU Configuration subsection reports you basic information about the CPU and allows to control some CPU-related technologies like virtualization.

Still we don’t see any of Intel’s CPU power-saving features because they are placed on a separate page called CPU Power Management Configuration. There are only three options here by default because CPU C States is set at Auto and the rest of the options are hidden. We changed CPU C States to Enabled to show you how many there are. They can affect the computer’s idle power draw, so you may want to specify them manually instead of letting the mainboard do that. In the example below we only need to set Package C-States Support.

The Monitor section is where you can check out the current temperatures, voltages and fan speeds. Fan management has been enhanced in the new BIOS. The Q-Fan Tuning option lets you calibrate your fans, for example. You can select a speed regulation mode for any of the fans supported by the mainboard: Standard, Silent, Turbo or max speed. Or you can set them up manually, too. In the latter case, you can use the Allow Fan Stop option to allow the mainboard to halt a fan altogether. Many modern mainboard have lost the ability to regulate 3-pin CPU cooler fans, but ASUS's recent models can do that. All of the fan connectors, both system and CPU ones, can reduce the speed of 3-pin fans. Besides CPU and mainboard temperatures, the mainboard reports chipset temperature as well as the reading from an auxiliary sensor. System fans (all six of them) can be regulated basing on any of these temperatures.

System startup options can be found in the Boot section. It’s here that you can change the start mode from EZ to Advanced. While setting the mainboard up for the first time, you may want to disable the Fast Boot parameter to make it easier to enter the BIOS interface.

Next goes the Tools section with a couple of most important subsections plus a nearly useless one. You can see the new Setup Animator option here. It lets you disable the animations to make the BIOS interface faster.

The integrated BIOS update tool called EZ Flash 2 is perhaps the handiest and most functional among the utilities of its kind. The support for NTFS partitions is only implemented in the BIOS update tools from ASUS and Intel as yet. Unfortunately, the option of saving the current BIOS prior to updating it has been removed altogether.

ASUS mainboards allow you to store and load up to eight profiles with full BIOS settings. Each profile can be given a descriptive name. BIOS profiles can be shared by saving and loading them from external disks. The profiles do not save the option of turning the startup picture off.

Like on mainboards from many other brands, we can now see the information written into the memory modules' SPD unit, including XMP profiles. It is not handy that we find it in the Tools section because memory timings are adjusted in a different part of the BIOS interface.

The last section, Exit, is where you can load BIOS defaults, apply or discard your changes. You can do all this via the hotkeys, though. The F7 key in the bottom right corner of the page lets you get back to EZ Mode whereas the Last Modified option, which lacks an assigned hotkey, shows a list of your last changes which is retained even after you reboot your computer. So you can always check out which BIOS changes you made the last time.

Similar to the Last Modified feature, a popup window shows the list of changes every time you are about to apply them. It provides an easy way to control your changes to BIOS options. This window also makes it easy to compare the current settings with what is written in the BIOS profiles. By loading a profile you will see all of its differences from the current settings in the window that opens up.

Summing up our BIOS overview, we should acknowledge that ASUS's UEFI BIOS has been revised dramatically. It has a lot of new features and options. Its EZ Mode is not useless anymore. It has more user-defined parameters. There are special wizards that can help you overclock your computer or build a RAID. You still have to switch to Advanced Mode for fine-tuning but EZ Mode is good enough for initial setting-up. The extended fan management capabilities must be noted, too. You can set up your fans flexibly right in the BIOS without any additional tools and utilities.

We won't criticize the new fonts or color scheme because it's a matter of taste. What we don't like is the new page layout. In the right part there is monitoring information about clock rates, temperatures and voltages while reference information is displayed at the bottom of the page. So the biggest downside of the new interface is that our view is smaller vertically because there’s the new hotkey line at the top and the Last Modified option with the F7 link (to return to EZ Mode) at the bottom. Of course, our view has also become broader horizontally but that was hardly a problem with the previous BIOS interface. Even small BIOS sections don’t fit into a single screen. The small viewport also makes it too easy to scroll past the option you need.

Although the UEFI BIOS from ASUS has a new interface, it doesn’t bring about significant changes. There are new setup options but the overall menu structure has remained the same. My Favorites or any other section cannot be used as the start screen, so there’s no point in selecting favorite options. Important power-saving technologies are still hidden deep in the BIOS structure. The ASUS SPD Information subsection is useless because it is separate from where you change memory frequencies and timings. Your turning-off of the startup picture is still not saved in BIOS profiles.

ASUS's BIOS is very good overall, but it is just annoying that the manufacturer hasn’t done anything for years to get rid of the mentioned flaws.

Testbed and Methods

We performed all our tests on a testbed built out of the following components:

We used Microsoft Windows 8.1 Enterprise 64-bit (Microsoft Windows version 6.3 build 9600) with latest updates and the AMD Catalyst 14.4 drivers.

We will compare the ASUS Z97-A with the Z87-PLUS model from the same manufacturer. It is a midrange model we haven’t tested before and it has all the characteristic traits of an ASUS mainboard like the CPU frequency drop at high loads. We won’t see much difference comparing two similar mainboards but our goal is to check out the two chipsets, the new Intel Z97 and the old Z87. We’ll be comparing mainboards with the same chipset in our upcoming review.

Operational specifics

We had no problems assembling our configuration with the ASUS Z97-A and updating the mainboard's firmware to the latest version. As is typical of all ASUS mainboards, the startup picture only mentions that you can press Del or F2 to enter the BIOS interface. ASUS persists in not telling us anything about the other active hotkeys. For example, you can press F8 to open a menu for choosing an out-of-order boot device but you can only learn about that from the user manual.

You can disable the startup picture with the Tab key (temporarily) or in the BIOS (permanently), but you won’t see any prompts, either. What you will see is information about the mainboard’s model name, BIOS version, CPU model, the amount and frequency of system memory, the number and type of USB devices, and the connected disks. The real CPU clock rate is not reported, though. The mainboard doesn’t count in any CPU overclocking you've done or any changes to the CPU frequency multiplier due to the Intel Turbo Boost technology. This downside is especially annoying as we know that ASUS’s ROG series products can correctly report both nominal and actual CPU clock rates.

Modern mainboards start up very fast and this may even present a problem for users of ASUS mainboards. It is only at the first launch that the mainboard lets you enter its BIOS. After that, the startup procedure gets so fast that you hardly have any time to hit the required key. The ASUS Z97-A lacks the DirectKey feature which would lead you right to the BIOS interface but has the so-called DirectKey Connector you can attach your computer case's Reset button to. DirectKey is not convenient, though. Instead of rebooting and entering the BIOS, it shuts the computer down first. Then you have to power it up again to find yourself in the BIOS. You can use the ASUS Boot Setting utility instead. Its functionality is okay, but you have to install it first. Moreover, it only runs under Microsoft Windows. So when you’re setting up your mainboard after purchasing it, you may want to disable the Fast Boot option in the Boot section, which is turned on by default.

The mainboard seems to provide standard conditions for the CPU by default but that's not really so. If you manually enable all of Intel’s power-saving technologies on the CPU Power Management Configuration page (in the CPU Configuration subsection of the Advanced section of the mainboard’s BIOS), you will make your computer substantially more economical.

You can also get some additional power savings by optimizing CPU Power Phase Control in the DIGI+ VRM page of the Ai Tweaker section. Then, you can also enable Power Decay Mode in the Internal CPU Power Management page and choose the balanced mode for the CPU Integrated VR Efficiency Management option.

Why don’t we just use the EPU Power Saving Mode? Well, we are rather wary of exclusive power-saving technologies because it is not clear what they actually do. They may supply lower voltage to the CPU or use lower CPU clock rates. The difference is going to be felt at high loads. For example, the EPU feature helped reduce the computer's power draw from 118 to 110 watts while running LinX. The idle power consumption didn’t change, though. It was still rather high at 42 watts. Our manual adjustment keeps the CPU working at its standard settings and doesn't affect its performance. We simply enable each and every power-saving feature the CPU already has. They are just not enabled by default. As a result, the idle power consumption goes down from 42 to 38 watts. So that’s what you should do first. And after you make your CPU as economical as possible, you may want to reduce your computer's power draw even more (although perhaps at the expense of performance) by applying any exclusive power-saving technologies from the mainboard maker.

As a matter of fact, all LGA1150 mainboards we've seen so far do not enable all of the CPU-related power-saving features by default. But ASUS products have one more downside. They are going to drop the CPU frequency multiplier to the base level at high loads although it should be higher due to the Intel Turbo Boost technology. To avoid this frequency drop, you should increase the CPU power targets in the mainboard's BIOS (Ai Tweaker -> Internal CPU Power Management).

Interestingly, you don’t have to specify those power targets yourself when you overclock. The mainboard will automatically increase them to ensure that the CPU frequency multiplier is as high as necessary. That’s why it is odd that the mainboard doesn’t do so at the default settings. Anyway, this problem only occurs at very high loads. It is unlikely to arise in everyday applications or games.

Overclocking

The ASUS Z97-A behaves like Z87-based products from the same brand at its default settings but there are some differences when it comes to overclocking. There’s the new EZ Tuning Wizard that’s supposed to help you overclock your computer and build a RAID. The latter feature may be easily overlooked, so we guess it should have been separated.

First off, the wizard identified that the CPU and memory worked at their default settings.

Then it inquired what the computer’s intended applications were. Of course, we answered that we wanted to play games and transcode video.

Then we were asked to choose the type of the CPU cooler. There’s a special answer for those who’ve purchased a ready-made computer and don’t know the details, but we use a tower-design Noctua NH-D14.

By the way, the Noctua NH-D14 has two 3-pin fans and none of the Socket FM2+ mainboards (based on the AMD A88X chipset) we tested, including an ASUS model, could regulate those fans, so they always rotated at their maximum speed. The ASUS Z97-A, on the contrary, provides full comfort by adjusting the speed of the fans depending on CPU load and temperature.

The wizard had no more questions to ask. It promised to boost CPU and memory performance but warned us that we should load the default settings in case of unstable operation.

This warning is necessary indeed as we realized after the computer had been rebooted.

The wizard raised the base clock rate a little, increased the CPU frequency multiplier to x44 and overclocked system memory using relaxed timings. Everything is okay so far, but the CPU voltage is going to be as high as 1.25 volts at high loads, which is too much. When the load is high and continuous, the CPU overheats, then drops its clock rate and speed. So, this overclocking is useless. The EZ Tuning Wizard algorithms need more optimizing. We don’t recommend using this feature until then.

Like with other ASUS mainboards, you can enable the ASUS MultiCore Enhancement option to increase the CPU frequency multiplier to its maximum level, which is normally used by Intel Turbo Boost for single-threaded loads only. It is set at Auto by default and doesn’t work. To enable it, you should do some overclocking, like changing your memory subsystem parameters with an XMP profile. For more substantial overclocking, the OC Tuner feature or the onboard TPU switch should be used. If you choose Ratio Only, the computer is overclocked by increasing the CPU frequency multiplier.

Of course, the result is lower than with EZ Tuning Wizard, but it will work even for high continuous loads. Interestingly, the OC Tuner feature used to adjust CPU parameters only but now it applies the XMP profile to speed up system memory, too.

And if you choose BCLK First, the OC Tuner feature will increase the base clock rate as well.

The resulting CPU clock rate is higher but the memory frequency is lower. The CPU voltage is higher in this case, too. But whatever OC Tuner method you choose, automatic overclocking is always imperfect, on any mainboard. You will get much better results by finding optimal system parameters manually. You will either reach higher clock rates or make your computer more efficient in terms of power consumption and heat dissipation.

The best way to overclock is without increasing voltage, but it is impossible to just set the CPU frequency multiplier higher and leave the rest of the settings intact. In this case, the mainboard will automatically increase the CPU voltage, and the CPU-integrated regulator will increase that voltage even higher at high loads. That is likely to end in overheat and, in any case, that's no energy-efficient overclocking at all. To avoid this, you have to change CPU Core Voltage to Manual. In this case, the mainboard and the integrated regulator don’t increase the voltage anymore.

You may also want to disable CPU Load-Line Calibration and Internal PLL Overvoltage, which may only be necessary for extreme overclocking.

Energy efficient overclocking is only possible if you don’t increase voltage. It will ensure higher performance and, despite the increased power consumption, you can expect long-term savings due to the reduced amount of energy spent for each computation. Energy efficient overclocking is going to be environment-friendly as we showed in our Power Consumption of Overclocked CPUs review. However, when we test mainboards, we want to check them out under different conditions and loads, so we choose what overclocking method ensures the highest results. Higher clock rates and voltages mean harsher test conditions and it is under such conditions that we can better see any flaws or problems in mainboard design.

We used to increase voltage in the offset mode and the LGA1150 CPUs also support a similar adaptive mode, but such methods do not work well with Haswell-based CPUs. The fact is as soon as the default voltage is changed even by a tiny value, the Haswell’s integrated regulator will spot it and increase the voltage further at high loads, which means high heat dissipation, high temperature and, eventually, overheat. To avoid this, the Haswell must be overclocked at a constant voltage. The downside is that the CPU’s power-saving technologies cease to work: the CPU frequency multiplier drops at low loads but the voltage doesn’t drop anymore and always remains at the constant and high level. This is the only way to deal with the integrated voltage regulator, though. Moreover, it doesn’t affect the computer’s power draw in idle mode. That’s why we overclock our CPU to 4.5 GHz in our mainboard reviews, fixing the voltage at 1.150 volts and using the XMP settings for our memory modules.

When we overclock by fixing the CPU voltage at a certain level, some of the power-saving technologies get disabled. The CPU's frequency multiplier is lowered at low loads but its voltage always remains high. Anyway, we stick to this overclocking for the duration of our tests, especially as it doesn't affect the computer's idle power draw much.

By the way, earlier we published an article called Haswell and LGA 1150 Platform: Right Operation and Overclocking where we explained the basic rules for optimizing LGA1150 platform parameters and for overclocking Haswell-based CPUs on mainboards from different brands. There you will find our illustrated recommendations on enabling Intel’s power-saving technologies and increasing CPU power targets as well as on how to overclock Haswell-based CPUs with and without voltage adjustment.

Performance

Nominal mode

We usually benchmark mainboards in two test modes: at the default settings and with the CPU and memory overclocked. The first mode is interesting because it shows how well the mainboards work with their default settings. It is a known fact that most users do not fine-tune their systems, they simply choose standard BIOS settings and do nothing else. So here is the performance you can expect from the mainboards if you don’t tweak their settings (the results of the ASUS Z97-A are colored differently).

We run the CPU test of the 3D rendering suite Cinebench 15 five times and calculate the average result.

We have been using Fritz Chess Benchmark for a long time already and it proves very illustrative. It generates repeatable results and its performance scales perfectly depending on the number of computing threads.

x264 FHD Benchmark v1.0.1 (64-bit) helps us test video transcoding performance. The original version of the benchmark with the version r2106 coder could make use of AVX instructions but we use version r2334 to enable the new AVX2 instruction set available on Haswell-based CPUs. The results are the average of five runs of the benchmark.

We benchmark performance in Adobe Photoshop CC using our custom test that is based on the Retouch Artists Photoshop Speed Test and consists of typical processing of four 24-megapixel images captured with a digital camera.

We use WinRAR 5.10 Beta 4 to benchmark the speed of archiving an Adobe Photoshop CC distribution.

Metro: Last Light is a very beautiful video game but its frame rate depends heavily on the graphics card. So we had to use the Medium Quality settings to maintain playability at a screen resolution of 1920x1080 pixels. The diagram shows the averaged results of five runs of the integrated benchmark.

F1 2013 is less demanding on the graphics subsystem than the previous game. At 1920x1080 pixels we chose the highest settings by enabling Ultra High Quality and all image-enhancing options. The diagram shows the averaged results of five runs of the integrated benchmark.

The new version of Thief is not acclaimed by critics, yet its visuals are top-notch. It’s got an integrated performance benchmark and lets you enable AMD’s Mantle technology. We had to choose Low Quality settings to see any effect from overclocking the computer. You wouldn’t need to overclock your CPU to enjoy the game, though.

The ASUS Z97-A and ASUS Z87-PLUS exchange their positions from one diagram to another, yet the difference between them is never large. Now let's see how our configurations perform with the CPU and memory overclocked.

Overclocked mode

We still can’t see any difference. The Intel Z97 has no advantages over the previous chipset in terms of performance.

Power Consumption

We perform our power consumption measurements with an Extech Power Analyzer 380803. This device is connected before the PSU and measures the power draw of the entire system (without the monitor), including the power loss that occurs on the PSU itself. In the idle mode we start the computer up and wait until it stops accessing the system drive. The mainboards are sorted in the order of ascending power consumption. The results of the ASUS Z97-A are colored differently for the sake of readability.

The difference between the mainboards is obvious now. The ASUS Z87-PLUS needs more power. Well, neither mainboard uses optimal settings by default, so let’s see what we have after we enable all of their CPU-related power-saving technologies.

Our configurations need less power now, yet the ASUS Z97-A is still more economical. It's hard to explain this result. The Z97 and Z87 chipsets are specified to have the same power draw of 4.1 watts. The mainboards both have 8-phase power systems. The Z87-PLUS has an additional SATA controller, but it can't account for such a big difference. There must be several factors contributing to it.

We want to remind you that we install an AMD Radeon HD 7970 graphics card into our test configurations. If we instead used the CPU-integrated graphics core, the overall power draw would be lower than 30 watts. Haswell-based CPUs are indeed very economical when idle, so it is a shame that the mainboards do not ensure this advantage by default. You have to correct some BIOS options for that.

For power consumption tests under high load we run the LinX 0.6.4 utility, which is a graphics shell for Intel’s Linpack test and supports AVX instructions. It is heavier on the CPU than ordinary applications, yet it is just an application nonetheless. It is quite possible that there are some other programs that can be just as heavy. That’s why we stick to using LinX for the purpose of checking the computer out for stability and for measuring its power consumption.

Both mainboards need 118 watts at this load, but the number doesn't reflect the typical power draw of LGA1150 products. These ASUS models drop their CPU clock rate at high load, so they consume less power but perform slower. The normal level of power consumption is somewhere above 130 watts. We'll see such numbers in our upcoming reviews of mainboards from other brands. However, if you manually increase the CPU power targets in the BIOS, even these mainboards from ASUS will become normal: they’ll consume more power and deliver higher performance.

Now let’s see how much power the mainboards need in idle mode when overclocked. We always use as many power-saving technologies as possible while overclocking. That’s why the standings are the same as at the default settings. The mainboards need 1 watt more compared to the Eco settings. However, both mainboards need less power when overclocked with increased voltage than at their default, non-optimized settings (see the first diagram). So, do not leave the settings at their defaults. You should explicitly enable all CPU-related power-saving technologies even if you don’t overclock your CPU.

By the way, you have to count in the graphics card’s power draw at high loads to calculate the overall system consumption. We use high CPU loads in our power consumption tests, but if we load the AMD Radeon HD 7970 by running some heavy game, the total power draw will be close to 250 watts at default settings and even higher at overclocking.

It is only in idle mode that the mainboards differ. They consume the same amount of power at high loads.

Conclusion

Our overall impression about the ASUS Z97-A is positive. It even looks better than the company’s earlier products. With less gold-plating, it has a more restrained appearance. And, besides its looks, it just works well. It offers good functionality and has no problems working at its default settings. It let us overclock our CPU and memory easily, too. The cut-down implementation of the M.2 connector is, of course, a downside as it makes the mainboard incompatible with the majority of currently available SSDs, yet it is hardly a critical defect.

The BIOS interface has been revised. We like the extended functionality of EZ Mode which is enabled by default. It can now be successfully used for initial setting-up. We like the extended fan management options. We like how the new interface looks but its layout seems questionable. Its viewport has become smaller vertically, so even rather small BIOS sections do not fit into a single screen and you have to scroll down to see them. And the small viewport makes it too easy to scroll past the option you need. The new EZ Tuning Wizard turned out to be useless for overclocking but the old OC Tuner feature has got better and is now able to overclock both the CPU and system memory. Well, manual overclocking is still better than automatic, anyway.

Although the UEFI BIOS from ASUS now has a new interface, it doesn’t bring about significant changes. There are new setup options but the overall menu structure has remained the same. My Favorites or any other section cannot be used as the start screen, so there’s no point in selecting favorite options. Important power-saving technologies are still hidden deep in the BIOS structure. The ASUS SPD Information subsection is useless because it is separate from where you change memory frequencies and timings. Your turning-off of the startup picture is still not saved in BIOS profiles. Typical of any ASUS mainboard, there are no hotkey hints in the startup picture. And if you turn it off, the mainboard will reports wrong CPU-related information. The boot-up process is accelerated by default, making it hard to enter the BIOS. At high loads the mainboard drops its CPU clock rate. These are all rather minor downsides, some of which you can even correct yourself. It is just annoying that the manufacturer hasn’t done anything for years to get rid of them.

As for the comparison of Z97- and Z87-based mainboards, we could see no difference between them. They are comparable in terms of functionality, performance and power consumption (we’ll need to carry out more tests to make sure that the newer mainboards need less power when idle). There are now a lot of Z97-based products with M.2 and SATA Express connectors but you can hardly expect anything extraordinary from compatible SSDs. The new chipset’s support for the upcoming Intel processors seems to be insignificant. We guess there will be newer mainboards with newer chipsets when those processors come out, so there’s no point in replacing a good LGA1150 mainboard with a Z97-based one. But you should certainly consider such mainboards if you’re building a new computer.