Workshop - OC and WC 8800 Ultra - how to break 12k 3dMark 2006 with 8800GTX and 13k with 8800 Ultra
Author: Luka Rakamaric
Date: 24 May 2007

With the launch of 8800 Ultra, just days before the R600 launch, NVIDIA wanted to confirm its leadership in the high end segment, but came out releasing a quite expensive card that didn?t produce the desired effect in the media. The return of the Ultra name after it was missing in the previous generation was supposed to have a big media impact, but almost everybody agreed that the clocks and the performance of the Ultra were not quite as expected because there were many factory OCed 8800GTX cards were on par or better. It is also the conclusion we came across in our own review, but after a few more weeks with the card we were able to do some interesting things.
Of the regular GTX cards, there are only a handful that could do a core clock of 675 MHz without voltmodding. A few more can go up to 648, and the majority is stuck at 621 MHz. The Ultra version of the card has a different revision of the chip, called G80 A3, compared to A2 in the GTX. It is supposed to be more efficient, and the Ultra actually consumes around 1% less power than the GTX, despite the increased frequencies. We were unwilling to believe that an increase of 37 MHz in stock clocks was everything NVIDIA could pull out of a new revision, so we decided to do a little experiment.

Our "game" was based around the feeling we had: there should be no problem in breaking 12.000 3dMark 2006 barrier with a single 8800 GTX card (ASUS EN8800GTX Aquatank), and there should also be no problem in breaking 13.000 barrier with a single 8800 Ultra. So, first we pushed Aquatank to the limit - as far as possible on our water-cooled testbed, and then took the cooler from Aquatank and put it on the Ultra card. Since the layout of these cards are identical, it was a no brainer to try it. The Ultra heatsink, although a little improved when compared to the GTX?s doesn't make a huge amount of difference in temperatures when thinking in parallel (old cooler-8800GTX, new cooler-8800 Ultra) and the GPU easily reaches 80 degrees, especially in a computer case. Using a water cooling system, we were able to put it down to just 54 degrees under load at stock clocks (612/1080MHz). The card wouldn?t go past 648 MHz using the default cooler, which was totally "unacceptable" for us. When we saw the 54 degree limit using the Aquatank cooler, we knew it was possible to do some serious overclocking. But first, check out our small workshop, step-by-step.

Our standard testbed was in action again:
- EVGA Black Pearl 680i motherboard
- Intel Core 2 Duo E6700
- OCZ PC2-6400 CL3 FlexXLC Edition
- OCZ GameXstream 850W
- WD RaptorX 150GB
- Dell 30" LCD display