Performance

Now we have to figure out one more thing: in what conditions we should measure ZOTAC nForce 790i-Supreme mainboard’s performance? Our Intel Core 2 Duo E8400 processor can overclock to 4.1GHz and this value can be reached several different ways. So, we considered four possibilities here:

1. overclocking to 450MHz FSB with x9 CPU clock multiplier and 1800MHz memory frequency – no performance drop because of FSB Strap in this case;
2. overclocking to 455MHz FSB with x9 CPU clock multiplier and 1820MHz memory frequency – maximum processor frequency in this case;
3. overclocking to 510MHz FSB with x8 CPU clock multiplier and 1632MHz memory frequency in synchronous mode with lowered timings;
4. overclocking to 510MHz FSB with x8 CPU clock multiplier and 1836MHz memory frequency in asynchronous mode.

Strange as it might seem, but all four situations turned out pretty close in terms of performance. However, we will have to disregard the memory tests in Everest, because in this case the first options becomes a real favorite, at lest until FSB Strap kicks in. In other test applications the performance difference was minimal, unlike FSB Strap on Intel 965P Express, where it has serious effect on the performance in majority of applications. Therefore, we decided not to draw any conclusions just yet and check out the results demonstrated by the competitor mainboard.

You already know fro the description of our testbed that we picked ASUS Maximus Extreme on Intel X38 Express to be the opponent in our today’s test session. There are a few reasons for this decision: it also supports DDR3 SDRAM, it overclocks CPUs well, you can increase its performance beyond average with Ai Clock Twister and Ai Transaction Booster parameters. MSI X48 Platinum mainboard on a more advanced Intel X48 Express chipset doesn’t have any of these features. Besides, it works poorly with the memory leaving Command Rate to 2T at all times, no matter what you set in the BIOS. Moreover, good mainboards on contemporary Intel chipsets, such as Intel X48 Express, Intel X38 Express and Intel X35 Express, perform almost identically. So, it is absolutely alright that we will compare ZOTAC nForce 790i-Supreme on NVIDIA nForce 790i Ultra SLI chipset against ASUS Maximus Extreme on not the very latest Intel core logic set.

The only problem was to find two more or less comparable operational modes for both mainboards. ZOTAC nForce 790i-Supreme works with 1800MHz memory with 8-8-8-24-1T timings, while ASUS Maximus extreme hasn’t been able to do the same so far.

Attention! If you are using two memory modules on an Nvidia nForce 790i Ultra SLI based mainboard with reference PCB design, you should better install them into those two DIMM slots that are the farthest from the processor socket: the second and the fourth one. In this case you will be able to hit higher frequencies at more aggressive timings than in case the modules sit in the “closest” slots – the first and the third. Theoretically, this rule should also work for other mainboards supporting DDR3, too, however, we need to double-check that before stating anything.

Unfortunately, nothing could help us get our ASUS Maximus Extreme to work stably with 1800MHz memory: we tried reflashing the BIOS with the latest available version and even moving the memory modules into the farthest slots. When we overclocked our Intel Core 2 Duo E8400 to 455MHz FSB with the default multiplier of x9, the memory frequency was only 1517MHz. However, we managed to set Ai Transaction Booster to +5 and lower the timings to 7-7-7-18-1T. This answered the question about the best operational mode for a fair comparison against ZOTAC nForce 790i-Supreme: it didn’t matter how our mainboard on NVIDIA nForce 790i Ultra SLI would work, if it still lost to the competitor no matter what.

So, we completed our test session. And looks like ZOTAC nForce 790i-Supreme mainboard boasts great accessories bundle, excellent PCB layout and functionality, good BIOS options, good dual-core processors and phenomenal quad-core processors overclocking potential. However, it suffers from FSB Strap and doesn’t perform very well. Doesn’t sound very optimistic, does it?

Yes, it does! Do you recall the mysterious undocumented P1 and P2 parameters in the FSB & Memory Config section that are set at Auto by default? It turned out that if you set them to Enabled, the mainboard will mysteriously transform. First, FSB Strap will vanish. And second, and this is the most important thing, the mainboard performance will increase so greatly that it will catch up with that of an Intel X38 Express based platform!

Here are the CPU and memory settings on our ZOTAC nForce 790i-Supreme mainboard:

And these are the same operational settings on our ASUS Maximus Extreme (MemSet utility doesn’t detect the memory frequency correctly, though):

And here are the results:

For a more illustrative comparison we highlighted the best results, however, the difference is very often within the measuring error anyway. As we see, Nvidia nForce 790i Ultra SLI based mainboard is as fast as the high-performance Intel X38 Express based one during overclocking.