We carried out our tests on a testbed that included the following components:
- Gigabyte G1.Sniper v1.0 (LGA1366, Intel X58 Express, BIOS F4b);
- Gigabyte GA-X58A-OC v1.0 (LGA1366, Intel X58 Express, BIOS F5b);
- Intel DX58SO2 (LGA1366, Intel X58 Express, BIOS 0817);
- Processor: Intel Core i7-970 (Gulftown, 6 cores, 3.2 GHz, 12 MB L3 cache, 130 W);
- Memory: 3 x 2048 MB DDR3 SDRAM Kingston KHX12800D3LLK3/6GX (1600 MHz, 8-8-8-24 timings, 1.65 V voltage);
- Graphics card: MSI N570GTX-M2D12D5/OC (Nvidia GeForce GTX 570, GF110, 40 nm, 786/4200 MHz, 320-bit GDDR5 1280 MB);
- Hard drive: Kingston SSD Now V+ Series (SNVP325-S2, 128 GB);
- Cooling system:
- Scythe Mugen 2 Revision B (SCMG-2100) CPU cooler;
- Additional 80x80 mm fan for cooling of the area around the CPU socket during overclocking experiments;
- Thermal interface: ARCTIC MX-2;
- Power Supply Unit: CoolerMaster RealPower M850 (RS-850-ESBA);
- System case: 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 126.96.36.1990, Nvidia GeForce/ION Driver 275.33 graphics card driver.
Operational and Overclocking Specifics
First I have to say that the system assembly with Gigabyte G1.Sniper went smoothly, but Gigabyte GA-X58A-OC didn’t want to take our Scythe Mugen 2 CPU cooler. Either the processor socket on this board was too close to the chipset North Bridge, or the retention holes for the North Bridge cooler are too far apart, but one of the North Bridge heatsink retention screws was in the way of the cooler backplate. I had to remove the screw completely, although later I still put it back in and tightened over the backplate. Of course, it is an isolated case and there may be absolutely no problem with a different processor cooler. However, I can’t think of any other mainboard where my Scythe Mugen 2 cooler wouldn’t fit.
Now I have to introduce to you my new Intel Core i7-970 processor, which is now part of our upgraded testbed. I used to work with a quad-core Intel Core i7-930 for testing Intel X58 Express based mainboards, but when LGA1155 processors came out, it became hopelessly outdated. Our article called “Core i7-990X Extreme Edition vs. Core i7-2600K” clearly showed that only six-core LGA1366 processors in some applications are capable of competing successfully against the new-generation CPUs, so it doesn’t make any sense to continue using quad-cores. Unfortunately, the six-core choices from Intel are limited to 1000-dollar Core i7 Extreme Edition and the only other CPU with reasonably high price – Intel Core i7-970, that is why our choice was pretty much pre-determined. However, a new Intel Core i7-980 has recently come to replace it. Its nominal clock frequency multiplier is 1x higher and that is the only difference between the new Core i7-980 and the older Core i7-970 model.
So, Intel Core i7-970 has six cores, supports Hyper-Threading technology, which allows it to use 12 computational threads simultaneously, is based on a 32 nm Gulftown core and features 12 MB L3 cache. Its nominal clock frequency multiplier is 24x, so with the base clock of 133 MHz its works at 3.2 GHz frequency. However, I doubt you will ever see this value, unless you try really hard. In idle mode the CPU lowers its Vcore, just like its fellow brothers, and its clock multiplier drops to 12x bringing the frequency down to 1.6 GHz.
And under heavy load Intel Turbo Boost technology increases the clock multiplier to 25x, so most of the time the CPU works at 3.33 GHz.
However, if the load is average and only one core is actually utilized, the clock frequency multiplier will rise to 26x and its clock speed will increase to 3.46 GHz.
However, these are only the nominal operational modes. If you remember, the power-saving technologies on Gigabyte GA-X58A-OC are all disabled by default that is why the processor doesn’t change the clock frequency multiplier, doesn’t lower the core voltage and works at 3.33 GHz and 1.25 V Vcore all the time.
Our preliminary tests showed that the CPU could be overclocked to 4.2 GHz. There are several different ways of obtaining this frequency. The easiest way is to limit the clock multiplier by 25x by disabling “C2/C6/C7 State Support” parameter in the BIOS and increasing the base clock to 168 MHz. The disadvantage of this approach is that the CPU will stop switching to deep power-saving modes and the idling system will consume more power than necessary. In our case, we also had a problem with memory. The Kingston KHX12800D3LLK3/6GX modules that we used could work at 1600 MHz, but could hardly overclock at all. At 168 MHz base clock the memory frequency could be set at 1680 MHz, but our modules were incapable even of that tiny increase. As a result, we had to drop the memory speed to 1344 MHz, which is pretty slow by today’s standards.