[H]ard|OCP

Navigation

• [H] Forums
• Archives
• Search
• [H] Folding

XFX nForce 790i Ultra Motherboard Preview

NVIDIA has a new nForce motherboard chipset for Intel’s newest CPUs that brings with it support for DDR3 and SLI. Some of you are excited, while I can already hear groans of agony from others. Let's give you the straight dope on 790i Ultra.

XFX 790i Ultra Overclocking

The XFX 790i Ultra has enough features to keep just about any tweaker happy. I won’t lie, there are things in the BIOS you will never use, toggle, or enable. And, as you will see below from our overclocking experience, you probably will not need to.

We used both a Core 2 Duo E8500 and Core 2 Extreme QX9770 for our overclocking testing. Both CPUs ran at stock speeds flawlessly and were properly detected by our motherboard.

The XFX 790i Ultra continues the tradition we have seen with past nForce chipsets when it comes to overclocking and that tradition is basically, “Don’t jack with anything in the BIOS that you don’t have to!” This does not apply to bleeding edge overclocks, but it will apply to most people just looking for a few extra free MHz out of their processor. With both our E8500 and QX9770 the “sweet spot” for Front Side Bus overclocking was 500MHz (Or “Quad Pumped” to 2000MHz). At 500MHz with both our E8500 and QX9770 we were able to get very effective and stable FSB overclocking without changing any settings in the motherboard BIOS besides those necessary. Pushing beyond 500MHz started to require some voltage tweaking. Keep in mind that power usage with these systems can be generally thought of as increasing exponentially rather than linearly. So cooling when overclocking is something to keep in mind, although our on-board cooling system seemed to do an excellent job with a simple 120mm fan blowing down onto board surface directly over the CPU socket.

It is fairly common knowledge that when we are able to “link & sync” the memory bus with our FSB on Intel nForce boards we get better memory throughput numbers and many times more stable overclocks. While “linking and syncing” did give us slightly better memory scores, it did not seem to make the board any more stable than when it was not “linked and synced.” This was all certainly good to see.

Worth noting is that NVIDIA advised that DIMM slots 1 and 3 (the black colored slots) be used for 2-up RAM configurations. This has to do with the way termination works on the DDR3 memory bus. Putting our Crucial Ballistix in DIMM slots 0 and 1 would negatively impact our overclocked memory scores by up to 1.5GB/s. So again, make sure you use DIMM slots 1 and 3 for 2-up configurations. If you have more than two sticks of RAM and use them in a 4-up configuration, you can count on not overclocking your RAM to more than about 1600MHz. This is not an nForce issue as you will find the exact situation on any comparable Intel chipset motherboard as well. So if you are a serious overclocker and are looking for 4GB of RAM in your system, 2GB sticks will be the way to go, but the price of entry on that configuration is very high.

Below are a couple results from our overclocking tests.

The top bus speed we could get out of our setup was 537MHz. A respectable overclock by any standards. It was however on the fringe of stability. As noted earlier we did not spend a tremendous amount of time configuring our overclocks and what you see above was fairly easy to get. We have heard of other getting bus speeds up to 560MHz. These new E8500 processors we are using have not be verified to run faster than the 537MHz bus noted here so I am not sure whether we are seeing a motherboard limitation or a CPU limitation.

Directly below the CPU-Z windows you can see that we ran a quick SiSoft Sandra memory bandwidth benchmark that netted us right at 11GB/s. The timings noted in CPU-Z are correct for our 2GB of Crucial Ballistix.

Pulling the FSB back to 525MHz gave us a much more stable base to overclock from and at that point I started ramping the clock multiplier on the CPU back up.

With fairly little effort and a minimal water cooling setup our E8500 Wolfdale was running at a stable 4.2GHz backed up by a 2GHz memory bus. Noted below the CPU-Z window you can see our 11.123 second Super Pi 1MB time. I do think that with some more time and a few days learning more about our BIOS that 4.6GHz with our E8500 would be possible on this 790i Ultra motherboard. It had no problem POSTing at 4.6GHz, but loading Windows was a bit of a problem.

I was very impressed with the Crucial Ballistix RAM at 2GHz and 9-9-9-21-31-1T timings. We did run the memory at the Crucial suggested 1.9v power rating. We have been using Ultra-X’s R.S.T. Pro for a number of years now to do memory testing.

Besides the Crucial Ballistix showing us perfect performance inside the Windows 64-bit OS, the RST Pro “Burn in” testing verified that the Ballistix RAM was behaving well at 2GHz. We could put the Ballistix to 2.06GHz or so, but then we started getting errors beyond that at the 9-9-9 timings at 1.9v.

Overclocking Summary

The XFX 790i Ultra exhibited very solid overclocking abilities on all fronts. High FSB, memory, and processor speeds were easily achieved through the robust BIOS. The board seems to have enough bells and whistles for tweakers to be kept busy for long periods of time while finding the high overclock speeds on the bleeding edge that elude others.