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GeForce 6800 Ultra & Power

We quickly discuss NVIDIA's GeForce 6800Ultra power requirements and give our opinions.

Introduction:

If you are not familiar with the newest generation of NVIDIA Graphics Processing Unit technology, we highly suggest you give our GeForce 6 Series Technical Article a read as NVIDIA has made some huge advances with their technology. If you would like to see a real-world gaming experience with the GeForce 6800Ultra you can read our original preview here, and where we face it against ATI's X800 technology here.

One of the issues that we did not explore fully in our preview was the buzz around the GeForce 6800Ultra's lofty 480 watt power supply requirements. The main reasoning behind this is that our 6800U that we currently have is a sample supplied by NVIDIA and not a retail card that a gamer would be able to purchase. We would much rather wait and do testing on "real" video cards. Now saying this might be a bit confusing so let me explain. In our experience, sample cards from NVIDIA have in fact shown to be very representative of the retail products you can buy in terms of Image Quality and framerate performance. On the subject of the rather high PSU wattage needs of the 6800U we felt as though the NVIDIA 6800U sample might not come close to representing retail cards in that retail 6800U video cards might be built by many different companies with all sorts of components on them from a long list of manufacturers. It is our thought that this could impact retail very differently from brand to brand. Certainly we will see when we test retail GeForce Series 6 cards.

The GeForce 6800U PSU Issue:

Earlier this week Gamespot posted an interview with NVIDIA's GM of Desktop GPUs, Ujesh Desai. We have met Ujesh on several occasions and found him to be very forthright in his answers to our questions. The interview outlined NVIDIA's actions in moving their 480 watt PSU specification for the 6800U to a 350 watt PSU which will of course be much more user friendly for many gamers out there.

A good quality 350W power supply with a sufficient 12V rail pull can support the 6800 Ultra standard clocks of 400/550.

Ujesh also went on to make this statement that we thought would of course be interesting to the hardware enthusiast.

For people that do not want to overclock, the 480W power supply and second power connector combination is overkill.

We knew very well from our 6800U testing in our preview that a 430 watt PSU worked quite well with our 6800U but we did run into some issues with not using both 4-pin Molex connectors. NVIDIA has never contacted HardOCP about 6800U specification changes so we set out to do our own bit of testing with the 6800U that had been supplied by NVIDIA.

The GeForce 6800U Testing:

First and foremost for those of you that may not be familiar with the 6800U power setup, you have two 4-pin Molex connectors on the card itself like seen below.

What we did was very simple. We tried running our 6800U with one or the other Molex power connectors plugged in and here are our results using our reference 6800Ultra with 61.11 beta drivers using a 431w Enermax PSU.

Primary and Secondary Molex Connector used – Operates normally in all conditions (2D/3D/Overclocking). 400MHz/1.1GHz.

Only Primary Molex Connector used – Power Indicator Warning in Windows “The NVIDIA system Sentinel is reporting that the NVIDIA-powered graphics card is not receiving sufficient power”. Coolbits reports 400MHz/1.1GHz still. Screen blinks off and on a lot making normal use in Windows not possible in 2D. Screen corruption in 2D, messed up icons, windows etc. Windows locked up in 2D on me a few times, had to hard re-boot. Not able to run any 3D games or benchmarks correctly. For example starting up a game it would launch but the graphics would not display, then the monitor would go blank and a Windows System Error box comes up saying “Microsoft Windows detected and recovered from a device failure.”

Only Secondary Molex Connector used – Turned on computer and the video card emitted an extremely loud tone through the speaker on the video card, no POST.

Conclusion: 6800U not useable with only the Primary OR only the Secondary Molex connector used. 6800U only works correctly with both power connectors used.

There is also some testing results in this thread at Beyond3D forums in which we helped out with last week and that did spur this topic on a bit.