We carried out our tests on a testbed that included the following components:
- MSI Z68A-GD80 (G3), MS-7672 ver.3.0 mainboard (LGA1155, Intel Z68 Express, BIOS version V18.6 B2);
- Intel Core i5-2500K CPU (3.3 GHz, Sandy Bridge, LGA1155);
- 2 x 2048 MB DDR3 SDRAM Patriot Extreme Performance Viper II Sector 5 Series PC3-16000, PVV34G2000LLKB (2000 MHz, 8-8-8-24 timings, 1.65 V voltage);
- MSI N570GTX-M2D12D5/OC graphics card (Nvidia GeForce GTX 570, GF110, 40 nm, 786/4200 MHz, 320-bit GDDR5 1280 MB);
- Kingston SSD Now V+ Series (SNVP325-S2, 128 GB);
- Scythe Mugen 2 Revision B (SCMG-2100) CPU cooler and an additional 80x80 mm fan for cooling of the area around the CPU socket during overclocking experiments;
- 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 188.8.131.520, Nvidia GeForce Driver 280.26 graphics card driver.
Operational and Overclocking Specifics
We didn’t experience any problems when we assembled our system on MSI Z68A-GD80 (G3) mainboard. It also worked perfectly fine in nominal mode. The only disappointment was the board’s inability to adjust the rotation speed of all fans other than the processor one. We almost always use an additional 80x80 mm fan for additional cooling of the area around the CPU socket during our overclocking experiments. The previous mainboard model with the B3 index could set the fan speed at 75% or 50%, but looks like they forgot to add this feature to the new BIOS version on the G3 mainboard. Therefore, on different occasions we adjusted the rotation speed of this additional fan either with Zalman FAN Mate 2 variable resistor, or via software tools, such as Speed FAN, which coped with the task very well. Unfortunately, the missing ability to adjust the rotation speed of any fans is not the only drawback of the new MSI Click BIOS II. The difference from the previous version is not only in the looks, because we have encountered a very serious problem that didn’t allow us to fully overclock our CPU.
If you press the OC Genie button on the mainboard or select “OC Genie II Mode” in the BIOS, you won’t have any problems. The mainboard will automatically increase the processor clock frequency to 4.2 GHz and at the same time significantly increase all voltages and disable all processor power-saving technologies. This is Micro-Star’s typical very non-optimal overclocked mode, which even commencing overclockers should avoid, and experienced users won’t ever use it anyway. The problems actually emerged when we tried to manually overclock our processor to higher frequencies than 4.2 GHz. The mainboard would start just fine even at the maximum clock frequency for our particular processor unit of 4.7 GHz, but during stability tests it would immediately drop its frequency to 4.3-4.4 GHz. In fact, this would be considered normal for any mainboard except ASUS and Gigabyte, if you forgot to push back the processor power consumption maximum in the “CPU features” section. So far, only the mainboards from these two manufacturers were able to automatically push back these thresholds, but now MSI Z68A-GD80 (G3) can do it, too. It automatically set the thresholds to 200 and 250 W during overclocking, but for some reason, it didn’t really work.
Of course, we immediately addressed this issue with MSI representatives and checked out quite a few BIOS versions and settings combinations, but the problem remained. The mainboard continued to drop the processor clock frequency multiplier under heavy load, so we couldn’t get any acceptable results. Eventually, the company’s engineers managed to identify and resolve the issue and we received a new BIOS version 18.62B, in which the processor clock multiplier stopped dropping under load and the mainboard could finally overclock well. However, it took a month of joint efforts to have it all sorted out and now we have a way to overclock processors on Micro-Star mainboards with all processor power-saving technologies remaining up and running.
Quite a few other mainboards don’t ever have a problem like that. We can always increase the processor core voltage in the “Offset” mode, when the necessary value is simply added to the nominal Vcore and all Intel’s processor power-saving technologies remain intact. However, for some reason this parameter is long gone from the BIOS of Micro-Star mainboards that is why we tested them using a different approach. Before, if we increased the processor core voltage, all power-saving technologies on MSI boards would get immediately disabled. If we left the Vcore untouched, then the mainboards increased it on their own during overclocking by raising the base clock and the outcome was exactly the same. Now things have changed. With MSI Z68A-GD80 (G3) it turned out that if you do not manually adjust the processor Vcore, the mainboard won’t raise it more than necessary and the power-saving technologies will stay active. Moreover, when the technology counteracting the processor Vcore drop under heavy load is enabled (it hasn’t yet disappeared from Micro-Star’s mainboard BIOS), the CPU Vcore stays at 1.4 V, which about what we need to push the CPU to 4.7-4.8 GHz clock speed. Unfortunately, we don’t have the best Intel Core i5-2500K unit, as it overclocks only to 4.7 GHz, but it means that even on an MSI mainboard we can now overclock our processor without losing all power-saving technologies!
However, reality made a few adjustments to our excitement. We discovered that when the CPU clock frequency is at 4.7 GHz, the mainboard cannot start without increasing the CPU Vcore. It booted just fine at 4.6 GHz, although we did receive a blue screen of death during OS loading, so we had to drop the clock to 4.5 GHz. As for the memory, our particular modules are a great fit for Micro-Star mainboards, as all latest models supported their operation at 1866 MHz frequency. In fact, it was an MSI mainboard that allowed us to hit from memory frequency for the first time in our lab, and only a little later the same could be repeated on the mainboards from other manufacturers. As a result, the final progress report for our overclocking tests looks as follows:
It is for the first time in a long time that all Intel’s processor power-saving technologies work perfectly fine during overclocking even on an MSI mainboard. The company’s proprietary APS (Active Phase Switching) technology that allows to dynamically change the number of active phases in the processor voltage regulator circuitry depending on the current CPU utilization still gets disabled, but most importantly, now the processor clock frequency multiplier as well as its core voltage both drop in idle mode.
Now we can finally compare the performance of different mainboards working in identical testing conditions. We can give up special modes, which we had to use for MSI mainboards. We had to sacrifice some of the overclocking success, but we encourage and support “smart” overclocking, that doesn’t require users to give up energy-efficiency even at the expense of a slightly lower maximum clock speed.