Testbed and Methods
We performed all our tests on a testbed built out of the following components:
- Mainboard: MSI Z87-G45 GAMING, MS-7821 ver. 1.2 (LGA1150, Intel Z87, BIOS V1.7)
- CPU: Intel Core i5-4670K CPU (3.6-3.8 GHz, 4 cores, Haswell, 22nm, 84 W, LGA1150)
- DDR3 SDRAM: 4x8GB G.SKILL TridentX F3-2133C9Q-32GTX (2133 MHz, 9-11-11-31-2N, 1.6 volts)
- Graphics card: Gigabyte GV-R797OC-3GD (AMD Radeon HD 7970, Tahiti, 28 nm, 1000/5500 MHz, 3072 MB of GDDR5 memory with 384-bit bus)
- Disk subsystem: Crucial m4 SSD (CT256M4SSD2, 256 GB, SATA 6 Gbit/s)
- CPU cooler: Scythe Mugen 3 Revision B (SCMG-3100)
- Thermal interface: ARCTIC MX-2
- PSU: Enhance EPS-1280GA 800 W
- Computer case: Antec Skeleton
We used Microsoft Windows 8.1 Enterprise 64-bit (Microsoft Windows version 6.3 build 9600), Intel Chipset Device Software version 126.96.36.1997, and the AMD Catalyst 13.9 graphics card driver.
It was simple and easy to assemble our configuration with the MSI Z87-G45 GAMING. We had no problems updating firmware and using this mainboard. The picture it shows you while starting up resembles the design of its product box. Some of the active hotkeys are mentioned at the bottom of the screen, although the Tab key, which removes the startup picture, is not listed among them for some reason.
The active hotkeys will still be mentioned even when the startup picture is turned off with Tab or with the related BIOS option. At the top of the screen the information is output about the mainboard’s model name and BIOS version, memory frequency and amount, and connected USB devices and drives. The installed CPU is identified correctly but its frequency is not always reported accurately. It is based on the Adjust CPU Ratio option in the BIOS's OC section but the actual CPU clock rate is going to be higher thanks to the Intel Turbo Boost technology. Moreover, the frequency multipliers of the CPU cores can be adjusted in the CPU Features subsection, and this is not counted in, either.
As opposed to many other LGA1150 products, the MSI Z87-G45 GAMING enables standard settings by default. However, if you manually change all the power-saving options of the CPU Features section in the mainboard's BIOS from Auto to Enabled, the power draw will be significantly reduced. In other words, the Z87-G45 GAMING doesn’t use all of the available power-saving techniques by default. This is typical of all LGA1150 mainboards we’ve tested so far. And the C1E Support option is even explicitly turned off by default on MSI mainboards.
Using the Enhanced Turbo option in the BIOS’s OC section, you can increase multithreaded performance a little by setting the CPU frequency multiplier at the maximum which is normally used by Intel Turbo Boost for single-threaded loads only. Well, every automatic overclocking feature is imperfect, just like the OC Genie button. You don't even have to test it in practice. Just click the button and enter the OC section to see what changes are going to be applied.
The CPU clock rate is going to be raised up to 4 GHz. This rather low value must be meant to ensure maximum stability with any CPU sample. The dynamic regulation of CPU clock rate is disabled, so the CPU is always clocked at 4 GHz, even at low loads. Intel's power-saving technologies are turned off, meaning that the CPU will always work at high voltage, too. That’s why this overclocking looks inefficient to us, even though it uses the XMP profile to increase memory clock rate. By the way, when you click the OC Genie button again to undo the overclocking, not all of BIOS parameters will return to their initial values. The Discard Changes option comes in handy then, but you have to use it in the Save & Exit subsection since it is missing among the hotkeys.
It would be much better to choose optimal overclocking settings manually instead of relying on automatic overclocking features. We recommend overclocking without any voltage modifications. If the CPU voltage is left at Auto, the mainboard won't increase it. In its turn, the integrated voltage regulator of your LGA1150 processor won't step voltage up too much at high loads, either.
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 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.
The article remains correct about MSI mainboards except that the Enhanced Intel SpeedStep technology doesn't get disabled anymore when you change your CPU frequency multiplier with the Adjust CPU Ratio parameter. Instead, there's a new thing you should know about. If you follow our earlier recommendations and change the CPU frequency multiplier in the CPU Features section, it may get lowered at high loads. To avoid this, you should manually increase the CPU power targets in the CPU Features or use the Adjust CPU Ratio option. This depends on your mainboard model and BIOS version, though. In our case, we could change the frequency multiplier using any BIOS options without any side effects.