We performed all our tests on a testbed built with the following components:
- ASRock X79 Extreme6/GB mainboard (BIOS version P1.20);
- Intel Core i7-3930K CPU (3.2-3.8 GHz, Sandy Bridge-E rev.C2, 32nm, 130 W, LGA 2011);
- 4 x 4 GB DDR3 SDRAM Corsair Vengeance CMZ16GX3M4X1866C9R (16 GB, 1866 MHz, 9-10-9-27 timings, 1.5 V voltage);
- MSI N570GTX-M2D12D5/OC graphics card (Nvidia GeForce GTX 570, GF110, 40 nm, 786/4200 MHz, 320-bit GDDR5 1280 MB);
- Crucial m4 SSD (CT256M4SSD2, 256 GB, SATA 6 Gbps);
- Noctua NH-D14 CPU cooler;
- ARCTIC MX-2 thermal interface;
- CoolerMaster RealPower M850 PSU (RS-850-ESBA);
- Open testbed built using Antec Skeleton system case.
We used Microsoft Windows 7 Ultimate SP1 64 bit (Microsoft Windows, Version 6.1, Build 7601: Service Pack 1) operating system, Intel Chipset Software Installation Utility version 220.127.116.119, Nvidia GeForce Driver 285.62 graphics card driver.
Operational and Overclocking Specifics
When we discussed the layout of the ASRock X79 Extreme6/GB we mentioned that the first graphics card slot and the processor socket are located very close to each other. Therefore, we had to install the graphics card into the second slot and it is important to keep this peculiarity in mind if you are planning to use several graphics accelerators in your system. Moreover, we wanted to make a few comments about the ASRock Game Blaster card. The sound ports on the mainboard are color coded that is why it is fairly easy to connect sound devices. However the sound ports on the card are not color coded or marked descriptively: they are simply numbered.
Just like with the fan on the chipset heatsink, we thought it would be an issue, but we were pleasantly surprised. It turned out that all connectors have colored LEDs inside them, so in fact, it is very easy to connect the cables, if you power up the system first. However, we did experience some difficulties at this stage, too, because we installed the ASRock Game Blaster card into the only PCI Express 2.0 x1 slot available right from the start, but only the additional network adapter started working in this case, and not the sound card. It took us a while to find out that the card was supposed to go into the last PCI Express x16 slot working as PCI-E x8. Actually, the manual does mention it, but we wish they made these instructions more obvious by placing an appropriate sticker, for example. Also it is important to keep in mind that with ASRock Game Blaster card installed, you will lose the support of the AMD 3-way CrossFireX and Nvidia 3-way SLI modes for good, because there will be only two graphics card slots left.
Just like with ASRock Fatal1ty X79 Professional, we didn’t immediately achieve stability in overclocked mode. Once again we had to give up the function enabling counteraction to the CPU core voltage drop under heavy load. Once in this case the system remained stable with the CPU overclocked to 4.5 GHz and the memory frequency increased to 1867 MHz.
This is not the highest frequency for our specific CPU sample, however, we were concerned about the heating of the processor voltage regulator circuitry during long-term stability tests under heavy load. We do not always report the CPU temperature in our reviews, but we always monitor it during overclocking experiments. We usually record the maximum temperature of the hottest processor core, as there are six cores and their temperatures are slightly different. However, in case of ASRock X79 Extreme6/GB all six CPU cores were running at the same 75°C after a one-hour run of Prime95. It is the first time in our experience that all six cores are showing identical temperatures. According to ASRock, the new BIOS should address the heating issue and as soon as we complete our additional testing we will provide an update regarding this matter.
We always overclock mainboards in such a way that they could be used for a prolonged period of time in this mode. We do not try to make our life easier by disabling any of the mainboard features, such as onboard controllers, for example. We also try to keep the CPU's power-saving technologies up and running normally to the best of our ability. And this time all power-saving technologies remained up and running even in overclocked mode lowering the CPU voltage and frequency multiplier in idle mode.