"MARVIN THE MARTIAN" suggested everyone read this in another thread.
(Can't remember which one or I'd link the post.)
It rates it's own thread as many avoid the F@H forums like the plague.
Posted by Dr. Pande 11/7/08 in "News"
"Culprit found in NV core v 1.15 issues for certain hardware?
Engineers at NVIDIA (notably Scott LeGrand) have come up with a theory for the EUE's seen in core 1.15 (and a few others in the 1.15 to 1.18 range) on certain hardware. They found that this core had code optimizations that drove the GPU so hard that it would draw a lot more electricity (one sign of this was running hotter). In some boxes, this was too much electricity and this lead to numerical instabilities. When the same machine was given a beefier power supply, the problem went away.
We've been told that 8800's require 600W power supplies, but we're finding that even a little bigger (eg at least 650W) is important to leave some room for error. We are working to see if there is some way to detect this issue in software, but for now, if you're getting EUE's on the NV GPU client, this is something to consider.
By the way, this will be very important for us to consider future code optimizations. NV core v1.19 removed some optimizations to solve this problem, but there are many cards which would run fine w/this more optimized code. If we can find a way to detect whether the card can draw enough power, we may be able to choose different code paths to allow for greater optimization for cards which can handle it.
We're still looking into this. For now, if you're seeing issues with your card, please consider trying out a bigger power supply. We will continue to look to see if this is indeed the problem and what we can do to help the situation such that the code runs stably on all machines."
Oddly one of my machines that had EUE problems also had the best (80 AMP 12v single rail) PSU.Core 1.18 helped with the EUEs on one core of a 9800gx2 on that rig. All my PSUs are 600W or better.
Posted as an FYI and a FWIW.
Ummm.. credit to MTM for seeing and reporting this first. We all have out hot buttons and I don't want to push anyone's.
Bookmarks