We performed all our tests on a testbed built with the following components:
- Mainboard: MSI Z77A-GD65, MS-7751 ver.2.1 (LGA 1155, Intel Z77 Express, BIOS version 10.5);
- Intel Core i5-3570K CPU (3.6-3.8 GHz, 4 cores, Ivy Bridge rev.E1, 22nm, 77 W, 1.05 V, LGA 1155);
- 2 x 4 GB DDR3 SDRAM Corsair Vengeance CMZ16GX3M4X1866C9R (1866 MHz, 9-10-9-27 timings, 1.5 V voltage);
- Gigabyte GV-T797OC-3GD (AMD Radeon HD 7970, Tahiti, 28 nm, 1000/5500 MHz, 384-bit GDDR5 3072 MB);
- Crucial m4 SSD (CT256M4SSD2, 256 GB, SATA 6 Gbps);
- Scythe Mugen 3 Revision B (SCMG-3100) 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 188.8.131.520, AMD Catalyst graphics card driver version 12.4.
Operational and Overclocking Specifics
We had no problems assembling our test system on MSI Z77A-GD65 mainboard. We encountered no unexpected issues or difficulties during our test session. Once you power on the system you will get a start-up image with a brief reminder of the available hot keys.
If you press the “Tab” key on your keyboard or disable the start-up image in the BIOS settings, the board will display the correct memory and processor frequencies but at the same time will keep the hot key reminder line at the bottom of the screen.
As usual, we first tried to check out the “OC Genie II” automatic overclocking function and once again saw that it was indeed far from perfect. Our Intel Core i5-3570K processor was overclocked only to 4.2 GHz and all power-saving technologies from Intel as well as MSI were fully disabled. However, if you use additional options on the “My OC Genie Options” page, you could achieve better results and keep Intel processor power-saving technologies up and running. Unfortunately, we couldn’t turn on the company’s proprietary APS (Active Phase Switching) technology that dynamically adjusts the number of active phases in the processor voltage regulator circuitry depending on the current operational load, because we can’t change any BIOS settings during automatic overclocking.
In other words, we accessed the BISO and enabled “CPU Phase Control” parameter in the “ECO” section that was disabled by default. However, after saving the changes, exiting and rebooting the system it still remained disabled. Luckily, we do not have to use the “OC Genie II” technology in order to boost the system performance. During manual overclocking we will definitely get better results, even though using Micro-Star’s mainboards for overclocking experiments does impose certain limitations. As you know, MSI mainboards are still unable to increase the processor core voltage in the “Offset” mode by simply adding the necessary value to the nominal. Therefore, in order to preserve all Intel processor power-saving technologies as well as MSI’s own APS technology we had to overclock without increasing the voltage. For this reason the mainboard failed to let our test processor reach its maximum frequency of 4.6 GHz, but once we enabled the counteraction to processor core voltage drop under heavy load the system remained stable at 4.5 GHz with the memory frequency increased to 1867 MHz.
Now I would only like to remind you that 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. MSI’s brand name APS technology was also enabled.