Overclocking and Performance

For our overclocking and performance tests we assembled an open testbed with the following hardware components:

• abit IX38 QuadGT mainboard, BIOS version 1.2;
• 2 x 1024MB Corsair Dominator TWIN2X2048-9136C5D;
• NVIDIA GeForce 8800 GTS 320MB graphics card;
• Seagate Barracuda 7200.10 (ST3320620AS) HDD, 7200RPM, 16MB, SATA 320GB;
• Zalman CNPS9700 LED CPU cooler;
• Antec NeoPower HE 550 PSU (550W).

Overclocking processors on abit IX38 QuadGT mainboard is extremely easy. Knowing what our test Intel Core 2 Extreme QX6700 CPU (2.66GHz, 266MHz FSB, 8MB, Kentsfield rev. B3) is capable of, we only had to set the corresponding parameters in the BIOS and in no time we hit its maximum frequency of 3.4GHz. The Intel Core 2 Duo E6300 processor (1.86GHz, 266MHz FSB, 2MB, Conroe-2M rev. B2) also overclocked to its maximum of 490MHz FSB without any problems. Thanks to rich and very conveniently implemented features of the abit IX38 QuadGT mainboard, it will be extremely easy to find the most optimal parameters for any other processor.

However, we still cannot claim that this is an ideal situation. abit IX38 QuadGT inherited not only the advantages of its predecessors, but also a few drawbacks. For example, just like abit IP35 Pro, the new abit IX38 QuadGT doesn’t allow to change the boot-up device during system start. If you need to boot from a USB flash drive or a CD disk all of a sudden, you will have to go into mainboard BIOS first and change the boot-up devices order and once the boot-up is successful, you will have to get back in there and change it again. A lot of other mainboard available today provide access to boot-up menu where you can immediately select the boot-up device.

Moreover, we have suddenly found out that if the processor voltage has been increased during overclocking, abit IX38 QuadGT mainboard, just like ASUS boards, cannot reduce the CPU Vcore if the workload gets low, although abit IP35 Pro had no problems with power-saving technologies. I hope that they can fix this issue. Digital processor voltage regulator implies additional flexibility and finer tuning for the system processor. So, we dare assume that they didn’t just give up the ability to reduce processor voltage in idle mode, and when they get more comfortable with this fairly new voltage regulator technology, it will be brought back.

Secondly, we were a little concerned about the memory timings abit IX38 QuadGT set during Intel Core 2 Duo E6300 overclocking to 490MHz FSB:

In fact, we have no problem with the timings, but the Performance Level is extremely high in this case. The lower is the Performance Level, the higher is the mainboard performance. I have never seen Performance Level above 9 on abit IP35 Pro mainboard. This time, however, it is automatically set to 10 and cannot be changed manually, like on ASUS mainboards, for instance.

The next problem occurred when we overclocked Intel Core 2 Extreme QX6700 processor using 9x clock multiplier in order to replicate overclocking of the popular Intel Core 2 Quad Q6600. The FSB frequency in this case was raised to 378MHz, which allowed us to push the CPU to 3.4GHz speed. If you remember from our previous article, we had to replace abit IP35 Pro mainboard with ASUS Blitz Formula on the same Intel P35 Express chipset in order to make sure that the performance was competitive with that of ASUS Maximus Extreme with DDR3 SDRAM running at 1.5GHz. abit IP35 Pro allowed setting the memory frequency to 945MHz, however, it was not enough, while 1134MHz was way too high. ASUS Blitz Formula is more flexible with the memory settings thanks to an intermediate divider that allowed setting the memory frequency to 1008MHz. Besides, its Ai Transaction Booster parameter allows setting manually the most optimal Performance Level for the given conditions. In case of abit IX38 QuadGT mainboard, everything happened exactly the same way. The mainboard works with the memory exactly the same way and Performance Level cannot be changed, just like on abit IP35 Pro.

In our article about Corsair Dominator TWIN2X2048-9136C5D memory modules we proved that they can work at 960MHz with 4-4-4-12-2T timings. You may believe that this guarantees the memory can work at 945MHz with these timings settings, however, in reality we failed to get it to run stably at this speed. This memory used to be tested on an Nvidia nForce 680i SLI based reference mainboard, and today we are using an Intel chipset. I doubt anyone will argue that Nvidia chipsets are more flexible than Intel ones when it comes to working with the memory subsystem. So, in the end, we had to keep the timings at their default values.

No wonder that abit IX38 QuadGT mainboard failed to withstand the aggression of ASUS Blitz Formula, where the same DDR2 SDRAM worked at higher speeds with the same timings, or ASUS Maximus Extreme that used even more high-frequency DDR3 memory. However, some of the tests from PCMark Vantage suite have a different opinion about it. Maybe we should replace this complex system performance test with a few separate but more adequate benchmarks in the future.

You shouldn’t pay too much attention to performance comparison between the different boards. Any good mainboard should be functional, convenient to work with, and the performance should better rest on the shoulders of the system processor and graphics card. However, this time we see that our hero lost to its competitors because of insufficient flexibility of abit IX38 QuadGT when working with the memory subsystem.