Dual GPU's not making 2x the credit...
29 Apr 2011 8:22:20 UTC
Topic 195772
(moderation:
Well I'm simply not seeing 2x the performance with 2x GPU's...
I upgraded to an X58 board, running 6 HT tasks + 1 for each GTX 460 OC, BUT !
One card in my i7-870 PC is averaging 17,000 but two faster cards in the X58 were only managing 21,500.
I wonder if it's some sort of Nvidia SLI behaviour, so have moved the 2nd GPU into a test PC for reliability testing.
None of the tools I have tried could correctly report on memory usage of the two GPU's, both showed 71 % utilisation, but one always reported 0 memory usage ?
Does anyone no of a piece of test software that can check reliability of CPU and/or GPU for use under BOINC ?
dunx
P.S. Under Nvidia's 270.61 my 8800 GTS is no longer any use here as it's memory is reported as only 264 Mb not 320 Mb ?
Dual GPU's not making 2x the credit...
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Did you remember to put the lines:
-
-
1
In a cc_config.xml file? This made both gpu's work for me, although with both gpu's being the same this is supposedly not needed, but until I did it the 2nd one would not work! I have dual Ati 5770's both crunching for Collatz and am seeing double the output, although at the moment I am just recovering from a 2 week vacation where all my machines were turned off.
The other thing to be wary of is the 2nd pci-e slot may not be a full speed slot, there have been reports of it only being a 2x slot, not the full 16x slot. I am guessing this is motherboard dependent.
Not: RE: - - 1
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Not:
But:
Just making sure you aren't advising people to put those dashes in front of the first two lines in cc_config.xml, as those will break the file.
RE: Not:RE: - - 1
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Yes I do not know where they came from, you ARE CORRECT they WILL cause issues!!!
RE: RE: Not:RE: - - 1
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They usually come from Windows users double-clicking on a file of type ".xml", which by default opens the file and displays it in Internet Explorer. The '-' and occasionally '+' symbols at the beginning of lines are tree collapse/expand controls added by Internet Explorer - they get converted to text if you copy/paste the IE display.
A note to people experimenting with .xml files for the first time - BOINC doesn't recognise the full range of XML standards. Just treat them as text files - use a simple text editor like Notepad or one of its replacements to edit BOINC's files.
Yes fairly happy that two
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Yes fairly happy that two GPU's are allegedly working...
Asus P6T6 WS is an X58 MoBo with either three 16x PCI-E slots, or six x8 ! !
If only I could afford six single slot GTX 460's...
Well, I'm now slowly gaining ever more credits in PC number three now !
I'm probably going to ATI for the next GPU card to run MilkyWay@Home on.
dunx
P.S. BOINC also has taken a dislike to my 320 Mb 8800GTS, which used to just sufficiently powerful to do some useful work, but now reports it as <300Mb of memory ? ?
RE: P.S. BOINC also has
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Not BOINC that's doing that, but your drivers. Nvidia has taken it upon themselves to save memory for its own operations, or some sort. So from some 2xx.xx drivers (I forget which), BOINC shows about 24MB less memory on video cards than there really is.
yes ! It has only happen
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yes ! It has only happen recently, SORRY BOINC !
Damned Nvidia... off into a friend's PC now then.
dunx
P.S. ATI 5870 next !
RE: P.S. ATI 5870 next
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OT: for Milkyway an untweaked HD6950 is a little more productive and more power efficient (less voltage needed). Unlocked and overclocked the HD5870 is no match. Go for the newer one if the HD5870 is not heavily discounted.
MrS
Scanning for our furry friends since Jan 2002
Yes, very heavily discounted
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Yes, very heavily discounted !
Worth the extra Watts, IMHO !
And fully warrantied too !
dunx
If your 2nd pci-e slot has
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If your 2nd pci-e slot has switched to x8 rather than x16 then you will see about a 20% drop in performance on the 2nd card. Also, einstein cuda is very cpu hungry. I only get full performance by running 50% max cpu. Anything over that and gpu task speeds drop off dramatically.