ASUS Maximus Extreme Mainboard Review

Today we are going to talk about ASUS mainboard on Intel X38 Express chipset with DDR3 SDRAM support. The mainboard is almost ideal: remarkable accessories bundle, superb PCB layout, outstanding and rich features. So, why “almost”? Read our review to find out!

by Doors4ever
02/05/2008 | 03:32 PM

Every ASUS Mainboard is an extremely interesting product, exclusively because it is made by ASUSTeK Computer Inc. Thanks to humongous production volumes and extensive channel connections this mainboard will be selling all over the world. However, in this case we are even more excited about it because ASUS Maximus Extreme is a top of the line solution.


It is based on Intel X38 Express chipset, is designed to work with DDR3 SDRAM and supports LGA775 Intel processors. Moreover, there are a few other reasons why we would love to talk about ASUS mainboards today.

So, this article is going to be devoted to Asus Maximus Extreme mainboard, its features, performance and supported technologies.

Package and Accessories

ASUS Maximus Extreme mainboard belongs to Republic of Gamers series and comes in a vertical box with a familiar design. The “shot through” front side bears the name of the mainboard and a few technology logos. The back of the box offers a list of mainboard’s technical specifications. The front side box panel can be flipped open to reveal more details about the mainboard’s features:


The board itself comes in a separate plastic casing that protects it against physical damage but at the same time doesn’t prevent you from checking out a few mainboard PCB components through the cut-out windows in the main package. All accessories are packed in a separate box and are pretty numerous. Inside this box we find:

Fusion Block System Accessory set including connecting pipes and clips is used to connect the chipset North Bridge water unit with a liquid cooling system.

DIY Pedestal rubber pads is one of the optional components, it comes exclusively with top ASUS mainboards. It is intended for those who will be using ASUS mainboard as an open testbed on top of the desk and helps improve the cooling, protect the desk top as well as mainboard itself from scratches. Also, according to the user’s manual, a creative user may think of some other use fort these self-adhesive rubber pads.

We have come across ASUS Optional Fan a few times already. It is a quiet fan that can be used as additional chipset cooling if necessary. For example, when there is a CPU liquid cooling system installed and the airflow inside the case is not sufficient.

We are also familiar with ASUS Q-Connector Kit already. Instead of finding the right connectors inside a dark system case almost by touch, we now can plug everything in using convenient markings on the block and then install the whole thing at once. The kit also includes similar adapters for USB and IEEE1394 connectors.

The LCD panel that displays the booting stages during system start-up first appeared on the rear panel of ASUS mainboards. Of course, this location was criticized a lot, because not everyone has easy access to the back panel of their system case. Now this panel can be placed anywhere you like:

In conclusion to the discussion of bundled accessories I would like to say a few words. We very rarely complain about scarce accessories bundled with the mainboards. The most important thing is that each board comes with the cables, user’s manual and drivers – without it we can’t really start the system. Everything else is nice addition to the product, which not everyone needs and which inevitably affects the price of the mainboard. ASUS Maximus Extreme board is a solution from the top price range that is why a few extras will hardly affect its price point. However, all these nice little things show very clearly that the manufacturer does its best to ensure comfortable and pleasant experience the user will have with the product, tries to foresee most users’ wishes. This same attention to small things and sincere desire to provide the best experience with their product will also show in the BIOS features and settings as well as in the PCB layout of ASUS Maximus Extreme mainboard.

PCB Design and Functionality

Tastes differ, but I think that quite a few people will be puzzled by the looks of ASUS Maximus Extreme at first glance. It looks very unusual. There are a lot of components that may seem confusing, the low-sitting DIMM slots may cause some concerns, but most questions are obviously connected with the massive cooling system where smooth rounded lines of some components hardly go together with edgy rough shapes of other.

However, I would like to defend the cooling system right from the start. Yes, it may look not very fine or inharmonious, but it is highly practical. It works extremely efficiently. We can even consider it the result of ASUS’ error correction to some extent, because the first version of chipset cooling aka Fusion Block System that could also be connected to a liquid-cooling system was introduced on ASUS Blitz Formula and ASUS Blitz Extreme mainboards. This is what it looked like:

So, a pretty hot Crosslinx chip is located between the PCI Express x16 slots and there is a heatpipes connecting it to the chipset South Bridge. Both chips are covered with heat-spreaders, not heatsinks. A small water block on top of the chipset North Bridge may be efficient enough to cool the chip, however, if you use air-cooling, like most users, then the heat generated by these three micro-chips and MOSFET transistors will have to be dissipated by a small heatsink enhanced with an additional unit on the rear panel. As a result, all these components will run pretty warm, so if you need to raise the chipset voltage quite noticeably, then you simply have to have a liquid-cooling system in place. The cooling system used on ASUS Maximus Extreme had to ensure proper cooling of the same number of components, however, the heat dissipation of the Intel X38 Express chipset is higher than that of P35. And they did make the right conclusions.

A large heatsink tops the Crosslinx chip and ICH9R South Bridge chip at the same time. It is not just a heat-spreader anymore, but a fully-fledged heatsink, though not a very tall one for obvious reasons. There are two heatpipes that lead from this heatsink to the cooling complex on top of the chipset North Bridge.

As you see, now the water block is enhanced with an additional heatsink that will not go to waste if you are not using any liquid-cooling in your system. Since this part of the system turned out pretty large, it is fastened using a backplate on bottom of the PCB.

One of the two heatpipes coming out of the chipset South Bridge leads to the base of the North Bridge heatsink. The other one continues beneath the additional heatsink and ends only between the MOSFET heatsink and an additional rear panel unit.

In fact, it is all a solid heatsink and the separate parts we mentioned are simply just parts of a solid system. The solid heatsink can dissipate the heat more effectively. Moreover, it has become significantly larger than a similar heatsink on ASUS Blitz Formula or ASUS Blitz Extreme.

Two heatsinks topping the MOSFET transistors are connected with the third heatpipe. This time, we have no complaints about the cooling system design, however, the processor socket turned out surrounded by the cooling system on three sides, which may pose an obstacle when installing and removing some of the CPU coolers.

However, nothing on the reverse side of the PCB was in the way, so our Zalman CMPS9700 LED got installed without any problems.

The memory slots were shifted down for a reason. ASUS Maximus Extreme features two-phase memory voltage regulator, which ensures longer life span of the components and provides higher overclocking potential. Although the DIMMs have been placed very low, their clips will never be blocked by the installed graphics card.

If the two blue PCI Express x16 slots are occupied, then they will be working at their full speed of x16, like on other Intel X38 Express based mainboards. The third slot, if there is one, usually works at x4 speed. The Crosslinx chip and ASUS’ unique technology implemented on Maximus Extreme retain the operation speed of the first slot at x16, while the other two slots work at x8. This allows to avoid performance bottleneck because of the too slot third clot.

There is one more technology called Voltiminder LED, which you can see in action when the system is on. There are three LEDs next to the processor cooling fan connector, next to the memory DIMMs, next to the chipset North and South Bridges. If the voltage on the corresponding knot is normal, the green LED is on. If the voltage has been increased - the yellow LED is on, and if the voltage is far beyond the nominal value – the red. Frequency LED – five light emitting diodes lined up in a row – allow estimating approximately how greatly the system has been overclocked. Besides, the Power On and Reset buttons are highlighted and the decorative panel on the chipset North Bridge heatsink also lights up. As a result, the board looks very festive, although you may change or even completely disable the LED lighting from the mainboard BIOS, if you wish.

The first mainboards from the Republic of Gamers series didn’t have any eSATA ports for some reason, while the regular ASUS mainboards did have them. This time, they took care of that, and involved a JMicron JMB363 controller providing not only PATA support but also two eSATA ports laid out on the mainboard connector panel.

Two RJ45 network connectors are implemented via the Marvell 88E8056 chip; VIA VT6308P is responsible for IEEE1394. There are PS/2 connectors for keyboard and mouse and six USB 2.0 ports. Moreover, as you remember, there is also an additional bracket with two USB 2.0 and one IEEE1394 ports bundled with the board. The Clear CMOS button is situated on the mainboard rear panel, together with an optical and coaxial SPDIF. All other audio connectors and jacks are located on an individual card aka SupremeXF II. The sound is provided by the eight-channel ADI 1988B codec.

Another small but convenient trifle: I/O Shield is highlighted, which make it a lot easier to connect all the cables.

All in all, we can conclude that despite very complex layout, ASUS engineers did a really great job. ASUS Maximus Extreme features everything necessary and doesn’t have any serious drawbacks. I would like to specifically stress that it allows connecting up to 8(!) fans and set the rotation speed of three of them depending on the readings from three additional thermal diodes included with the board.


Now that we have completed the discussion of exterior features of our ASUS Maximus Extreme mainboard, it is time we summed up its features in a detailed specification table.

BIOS Setup

The BIOS of ASUS Maximus Extreme mainboard is based on AMI micro-code. The first page looks very common and standard, but the second one demonstrates all the goodies this board has to offer. However, you will not see the entire set of Extreme Tweaker options right away. Here is what you get at first:

CPU Level UP parameter allows pushing the processor overclocking to the desired level. The available list may vary depending on the CPU you’ve got.

Memory Level Up parameter works in a similar way, although there are fewer options available here.

Among the options within Ai Overclock Tuner you can now see new technology called X.M.P. (Extended Memory Profiles). The memory modules SPD may contain info on their overclocking friendly features, so by selecting this item from the menu you will ensure that the memory will be set up in accordance with the overclocking parameters from the SPD.

If we decide to adjust I Overclock Tuner manually, we will be able to change the FSB frequency from 200MHz to 800MHz and PCI-E frequency from 100MHz to 150MHz. However, the memory frequency adjustment turns a bit tricky. The list of available parameters is pretty long, but the very last two marked with "*" are not available in the manual mode.

The thing is that when you set the memory frequency at 1600MHz or 1800MHz, the appropriate FSB frequency and processor clock multiplier are automatically selected, which is reported in the informational window on the right.

For example, when we select DDR3-1600MHz and use a CPU with 2.66GHz (266x10) frequency, the FSB gets increased to 400MHz and the multiplier reduces to 7. As a result, the processor frequency increased insignificantly and equaled 2.8GHz (400x7), however the memory worked at 800 (1600) MHz as was promised right from the start.

As for the memory timings, there are two informational strings that report their current settings. If you decide to adjust something, you get access to the entire list:

Ai Clock Twister parameter also belongs to memory settings section. It can be set at Auto, Moderate, Light or Strong. Ai Clock Twister does have certain influence on the performance and may help during system fine tuning, however, it is the Ai Transaction Booster that still plays the most important role and allows changing the Performance Level.

Since we decided to set Ai Overclock Tuner manually, we got access to previously unavailable voltage settings:

The voltage settings are not only numerous, but they also can be adjusted within very wide ranges. For example, processor Vcore can be adjusted in the interval from 1.1V to 1.9V with a tiny increment of 0.00625V, and then up to 2.4V with 0.025V increment. Other available voltages are the following:

When the set voltage is far over the nominal value the green numbers turn yellow, and in case of dangerously high values – red. Loadline Calibration parameter prevents the processor core voltage from dropping under workload, according to Intel’s official specification.

The last part of Extreme Tweaker section is devoted to Voltiminder LED, Frequency LED, CPU and PCIE Spread Spectrum management.

Advanced Menu section offers traditional options for CPU configuration, for instance.

Onboard Devices Configuration page allows working with the integrated controllers and external LCD panel.

Everything else is quite common and traditional. I would only like to draw your attention to the hardware Monitor page in the Power section. The list of options available there also doesn’t fit into a single screen:

ASUS Maximus Extreme mainboard allows monitoring 7 temperatures, including three temperatures reported by external thermal diodes that come with the board. COP EX Technology protects the chipset and other selected components from overheating. The rotation speed of processor and case fans can be adjusted automatically. Unfortunately, the rotation speed of a three-pin fan plugged into a four-pin fan connector cannot be adjusted.

There is a separate configuration page for the three additional fans with external thermal diodes. Their rotation speed can be set variable in accordance with the corresponding temperature readings or remain constant in the interval between 70 and 100%.

As for the voltage monitoring, ASUS Maximus Extreme mainboard also offers extensive opportunities for that. It allows monitoring not only the voltages from the system PSU, but also those delivered to the crucial system components.

Boot section allows setting boot-up parameters and the booting devices order. Tools section contains a built-in EZ Flash 2 utility with very convenient graphics interface for updating the BIOS and allows saving two complete settings profiles using O.C.Profile function. You can also save these profiles on external storage devices and exchange them with your friends.

I assume, you will agree with me that ASUS Maximus Extreme boasts truly excellent BIOS features. In some cases, I would even say there are excessively rich :)

Overclocking and Performance

When it came to overclocking, we had only one single issue in the very beginning: the mainboard wouldn’t start after CPU overclocking. However, it was not the mainboard, but my own mistake: I should have paid attention to the info displayed in the BIOS window on the right when I changed the parameters:

The memory frequency I set was too low, so once I raised it appropriately, everything continued smoothly. Intel Core 2 Extreme QX6700 processor (2.66GHz, 266MHz FSB, 8MB, Kentsfield rev.B3) overclocked to 3.4GHz and remained stable in several configurations:

Quad-core Kentsfield processors are usually very uneager to get past 450MHz FSB, they require significant Vcore increase. However the board itself can do way better than that: dual-core Intel Core 2 Duo E6300 processor (1.86GHz, 266MHz FSB, 2MB, Conroe-2M rev.B2) overclocked easily to its maximum of 490MHz FSB. We didn’t use the Clear CMOS button even once, because C.P.R. (CPU Parameter Recall) technology on ASUS Maximus Extreme mainboard works perfectly fine. After the first failed boot-up attempt, the mainboard restarts with safe BIOS settings, stops right after POST and offers to access BIOS to adjust faulty parameters. Moreover, the BIOS settings do not get reset to their nominal values. This is ideal work strategy for finding the most optimal BIOS settings during overclocking.

As for the performance of ASUS Maximus Extreme, there is a wide spread opinion that DDR3 SDRAM cannot compete against DDR2 SDRAM because of high latencies. It is true if your processor works in nominal mode. You will actually have to make certain effort to ensure that your system doesn’t fall too far behind the faster predecessor. However, during overclocking the situation changes dramatically. For example, the system with Intel Core 2 Extreme QX6700 processor overclocked to 3.4GHz on abit IP35 Pro mainboard equipped with 2x1024MB DDR2 SDRAM from Corsair (Dominator TWIN2X2048-9136C5D) turned out much slower. Nothing surprising about it, actually, since DDR2 SDRAM worked at about 1GHz speed, while on ASUS Maximus Extreme DDR3 was running at 1.5 times higher speed during the same processor overclocking.

Nominal frequency of Corsair Dominator TWIN2X2048-9136C5D memory is formally 1142MHz. The next divider that can be used on abit IP35 Pro mainboard during overclocking sets memory speed at 1134MHz, however the system wouldn’t run stably in this case. After a number of failed attempts we replaced abit IP35 Pro mainboard with ASUS Blitz Formula on the same Intel P35 Express chipset. I hoped that Ai Transaction Booster will help increase the Performance Level, which abit mainboard usually sets aggressively low. No luck, although replacing the board did have a positive outcome: ASUS Blitz Formula mainboard gave us an additional memory divider. For example, if we set the multiplier to x9 for Intel Core 2 Extreme QX6700 processor in order to imitate overclocking the popular Core 2 Quad Q6600, then the memory frequency needs to drop down to 945MHz on abit IP35 Pro, because it doesn’t allow setting it at 1134MHz. ASUS Blitz Formula, however, has an intermediate divider providing quite attainable 1008MHz frequency value for the memory.

As a result, Intel Core 2 Extreme QX6700 processor overclocked to the same 3.4GHz on both mainboards:

ASUS Blitz Formula - left, ASUS Maximus Extreme - right

DDR2 SDRAM worked at 1008MHz on ASUS Blitz Formula, and DDR3 – at 1512MHz on ASUS Maximus Extreme.

ASUS Blitz Formula - left, ASUS Maximus Extreme - right

Of course, the timings were also very different in both cases:


These were the settings when we ran memory subsystem benchmarks from the Everest suite for both systems:

Unfortunately, we failed to catch up with DDR3 SDRAM. Write speed depends on the FSB frequency that is why it was equal in both cases. Other than that, DDR3 outperforms DDr2, even in terms of latencies. The frequency difference is way too great.

Taking into account that all other components of our test platforms were the same, and the CPU was overclocked to the same frequency, we expected the system with DDR3 SDRAM to outperform the one with DDR2 memory or will run at about the same speed if the benchmark is not very memory sensitive. All in all, everything turned out exactly this way, with a few exceptions though:

For some reason, 3DMark06 CPU test puts the DDR3 system ahead of the competitor although the processor frequency was the same in both cases. We have known for a long time that this benchmark is not very valuable from the practical standpoint, however, all intermediate benchmarks from PCMark Vantage except PCMark Vantage gaming showed DDR2 system as the winner. Since there were no prerequisites for that, we have to admit that PCMark Vantage, just like its predecessors doesn’t really depict the actual situation that well.

Anyway, you should understand that we had to use and specifically configure another ASUS mainboard for it to perform as fast as ASUS Maximus Extreme with DDR3 SDRAM. Far not every mainboard working with DDR2 memory will be able to perform at the same level, and as for DDR3 SDRAM, 1.5GHz frequency is far not the maximum it can do these days. So, I assume overclockers should start paying more attention to DDR3 SDRAM.

ASUS Mainboards and Power Consumption

Well, ASUS Maximus Extreme mainboard looks almost ideal – it is fast, very convenient to work with, offers excellent features. However, it is time we through in something that may spot a number of other ASUS mainboards as well.

When our Platform lab received the Intel Core 2 Extreme QX6700 processor, we decided to check it out on ASUS P5K3 Deluxe. Unlike other mainboards on Intel P35 Express, it didn’t have any problems with CPU overclocking. This time everything was also going on just fine. All the power-saving technologies were enabled, when I suddenly noticed that in idle mode the processor clock frequency multiplier dropped to x6, while the voltage remained unchanged…

We decided to get to the roots of this strange phenomenon. Our investigation revealed that in nominal mode and after slight overclocking everything works fine, but the voltage stops decreasing as soon as we change the BIOS setting to anything other than Auto or when the “smart” mainboard increases it on its own for further CPU overclocking.

Too bad, I really liked ASUS P5K3 Deluxe mainboard, however, this frustrating feature made me pretty upset. And what about other ASUS mainboards on Intel P35 Express? We checked out ASUS Blitz Formula, which proved to act in exactly the same way. But when did it all start? Our tests showed that ASUS Commando on Intel P965 Express also does the same thing. We managed to track this problem back to ASUS mainboards on Intel 975X chipset. Unfortunately, we didn’t have any older ones at hand.

I wonder why I never noticed it before? CPUs very rarely idle in testbeds, however, I haven’t noticed anything like that even on my home system for a while. I believe I just didn’t pay enough attention to the actual voltage settings. I assumed that since all power-saving technologies were enabled, they should have been working properly.

It is ironic, however, that I overclocked a CPU on my home platform, but lowered the voltage a little bit because the mainboard would actually report it higher. As a result, the processor would receive 1.33-1.34V in any work mode. If I returned the processor Vcore setting to Auto, then it would be at extremely high value of 1.38-1.39V when the CPU was running full speed, however in idle mode it would drop down to 1.23-1.24V. In fact I was very surprised why my processor was running at over 45ºC in idle mode, but I though I just got a little “warmer” unit. However, the reality was very simple: while I believed that my processor was in economy mode, it was in fact wasting the power. And it is not only about economy, actually. Temperature dropped and so did the rotation speed of the processor fan, making the system much quieter. However, now I have to put up with higher power consumption and more noise for the sake of more comfortable work mode under low workload.

In fact, I could put up with this fact, if giving up power-saving technologies were determined by peculiarities of Intel processors or mainboard chipsets. However, all mainboards from other manufacturers do not have this problem. So, why do I have to face this complicated choice with ASUS mainboards, while I am entitled to get flawless performance at maximum frequency when needed and lower power consumption and noise in idle mode?

Right from the start when Conroe processors appeared, Intel had been struggling to make them as economical as possible. If you remember, first processor revisions consumed about 20W in idle mode, then they reduced this number to 12W, and then to the impressive 8W. However, those overclockers who own ASUS mainboards, cannot take advantage of this. ASUS EPU (Energy processing Unit) Technology that should monitor and adjust processor power consumption under different workloads doesn’t really contribute much to the power-saving (for details see our article called ASUS P5E Mainboard Review). Besides, the fact that they gave up Intel’s EIST leads to a lot of wasted watts of power, and the higher the processor Vcore is, the bigger the waste.

Different problems and mistakes tend to accumulate with the time. Contemporary ASUS mainboards starting with the ones on Intel P965 Express chipset lost their ability to adjust the rotation speed of three-pin fans, although a lot of other mainboards can still do it. Why? Now this power consumption issue. Why again?

I have believed until recently that there is no alternative to overclocker mainboards from ASUS out there. Now I am no longer that categorical. Namely there are a few companies who can successfully compete against ASUS. Take abit for instance with their extremely successful IP35 Pro. Of course, abit and ASUS cannot be compared to one another in terms of size, however, Gigabyte, for instance can compete with them in terms of products capacities and sales volumes, and as for overclocking-friendly features, we have to give due credit to Gigabyte for making a lot of progress in this direction over the past years. Foxconn is another strong player, with big potential. Theoretically, any manufacturer can design a successful product. The only problem is that it is really hard to release one successful mainboard after another. And ASUS have to put themselves together, because competitors are wide awake.


ASUS Maximus Extreme doesn’t give you a single reason for disappointment. Right from the start when you open the box you get the feeling that the manufacturer did its real best to accommodate all your needs and wishes and make the work with this solution a pleasant and memorable experience. This feeling comes from the accessories bundle, the PCB layout, outstanding and rich features – absolutely all work aspects. A few frustrating issues, such as inability to adjust rotation speed of three-pin fans and ignored power-saving technologies do not allow us to call ASUS Maximus Extreme an ideal mainboard.  But ideal mainboards simply do not exist, and ASUS Maximus Extreme got extremely close to this title.

Actually, have you ever thought what “an issue” is? It is, in fact, very individual. If you have a CPU cooler with a four-pin connector, you will not even notice the rotation speed adjustment issue we mentioned above. And if your CPU is always loaded to the full extent with some distributed computing applications, for instance, then you will never really face the non-operational power-saving technologies on ASUS mainboards.

There are no ideal solutions, that is why the user has to find a mainboards, which drawbacks will not be crucial for his particular needs. And our task is to describe the products in enough detail revealing all cons and pros, so that this choice could be as easy for you as possible. And we intent to continue doing it, so stay tuned!