We performed all our tests on a testbed built with the following components:
- Intel DZ77GA-70K (LGA1155, Intel Z77 Express, BIOS version 0045);
- Intel DZ77RE-75K (LGA1155, Intel Z77 Express, BIOS version 0045);
- 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 220.127.116.110, AMD Catalyst graphics card driver version 12.4.
Operational and Overclocking Specifics
There were no problems during the testbed assembly on Intel DZ77RE-75K and Intel DZ77GA-70K mainboards. Both boards worked impeccably in default mode, although it was pretty strange to find out that not all power-saving technologies were enabled by default. Upon system boot we see a startup image. Unlike other mainboards, the ones from Intel let you select the list of hot keys to be displayed during startup.
You can take advantage of the optimizations that accelerate mainboard boot-up, such as disabling the startup image. However, it won’t reveal any additional useful info in anyway.
It is recommended to update the BIOS by launching a self-extracting archive, which will automatically reflash the BIOS. However, this approach will not work for any operating systems other than Microsoft Windows. We used a built-in updating tool, which can be launched by pressing F7 during system startup.
Note that besides the USB drive with the new BIOS update, the list also contains both partitions of the connected SSD, i.e. it supports NTFS file system, unlike many other integrated utilities that come with competitor mainboards.
Once you found the file containing the new BIOS version, you just need to confirm your decision to update.
While in nominal mode both mainboards worked flawlessly, during overclocking we faced multiple issues of different sorts. At first we couldn’t even figure out what caused such unpredictable mainboard behavior, but later we discovered that the profiles in Visual BIOS did not work correctly. Such parameters as memory frequency, load-line calibration and Processor Power Efficiency Policy couldn’t be saved or recovered. Trying to find answers we found ourselves on the page with the parameters of the integrated graphics core and were shocked with what we saw! It turned out that when you try to load any existing profile, the boards attempt to increase the voltage by 27303 mV, although the integrated graphics is supposed to get automatically disabled with a discrete graphics accelerator installed.
The boards are hardly capable of feeding over 27 V, and it is merely evidence that the current version of Intel’s new Visual BIOS is still far from perfect. However, we completely gave up on it only after the CPU Vcore had increased by 20 mV with default settings profile. By the way, 20 mV is the minimal increment in Offset mode and it is way too big for contemporary processors, which nominal voltages are around 1V.
However, it is still possible to overclock processors with Intel mainboards if you witch from the new Visual BIOS to the old Classic one. The thing is that both BIOS types are not identical. For example, Visual BIOS promises to raise the graphics core voltage by 27303 mV, while the old BIOS is eager to do with just 68 mV.
Both BIOS types do not report the correct memory settings. For example, the new BIOS thinks that you can get different memory frequencies by using the same 10x multiplier.
The same operational mode in the old BIOS looks differently, but is also incorrect:
Of course, I can’t say that there are two completely independent BIOS systems on each of these boards, but they behave totally different. As for the settings profiles, each BIOS saves its own profiles, and they do not interfere with each other in any way. So, we started using the classic BIOS version to save and restore settings profiles. It also wasn’t ideal, because it couldn’t save the temperatures set in “Fan Control & Real-Time Monitoring” sub-section, but it saved and restored correctly all major frequencies, multipliers and voltages.
However, even when we switched to the classic BIOS version, we didn’t get rid of all overclocking-related issues. We failed to overclock our processor to its maximum of 4.6 GHz. WE couldn’t achieve stability at 4.5 GHz, and even at the relatively low frequency of only 4.4 GHz the errors would pop up all the time. And every time we tried to use “Overclocking Assistant”, the boards would immediately increase the frequency and voltage of the integrated graphics core.
As a result, we had to resort to a complex combination overclocking method. All initial parameters were set in the new “Visual BIOS”, then we switched to the classic BIOS where we saved and loaded the settings profiles. This way we managed to push the CPU clock to 4.5 GHz, and the memory clock to 1867 MHz on both tested mainboards. By the way, if you take a closer look at AIDA screenshots, you will see where the name of this review is coming from: “Roads End” and “Gasper” are the codenames for Intel DZ77RE-75K and Intel DZ77GA-70K mainboards respectively.
In the meanwhile we uncovered the already existing issue of Intel mainboards: they either set all memory timings automatically, or you have to set all of them manually. It turned out that the same was true for the X.M.P. profiles. All other manufacturers’ mainboards used the X.M.P. profile for our particular memory modules and set the memory frequency to 1867 MHz with 9-10-9-27-2T timings. All of them allowed changing the timings to 9-10-9-27-1T, but not the Intel boards. To be fair, I have to add that EVGA mainboards also behave the same exact way, but nevertheless it is no excuse for Intel.
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 during overclocking lowering the CPU voltage and frequency multiplier in idle mode.
There is pretty much nothing to say about the bundled software. Now there is even no “Intel Extreme Tuning Utility” included with the boards, though it used to be bundled with all Extreme series mainboards before. It could be because they are still polishing off their new Visual BIOS. You can only download the ancient “Intel Desktop Utilities” suite, which is hopelessly outdated and is unable to indicate correct CPU frequency or SSD temp.