Hi All

I have two intel Q6600 machines,both with 2 gig RAM. one has an SLi mobo and one doesn't. I used to run XP pro (32 bit) on both machines each with a single GTX260 (XFX 260 ADEF).

both machines used to take around 6.5 hours per WU.

At the weekend I added a second identical GTX260 (XFX 260 ADEF) to the SLi machine. I also (and I hear you all laughing at this next bit.. ;-), because I wanted to run DirectX 10 games on this stonking new graphics powerhouse!!) "upgraded" (it was a complete disk reformat BTW) XP pro to Vista Home Premium..............

now, low and behold, the WU's are taking 8.5 hours each on the Dual GPU and still 6.5 in the mono GPU. :-/

so my question is....

is there a performance drop when comparing XP Pro to Vista or single to multi GPU's??


heres links to some examples...

Single GPU machine
http://www.gpugrid.net/results.php?hostid=162


Vista dual GPU machine
http://www.gpugrid.net/results.php?hostid=32557

Same Machine running XP with Single GPU (before "upgrade").
http://www.gpugrid.net/workunit.php?wuid=370356
(ignore the OS on the computer spec, it was XP but the machines got "merged" by Boinc!!)


I have a sneaking feeling that my Bill Gates punchbag may be having another "workout" but wanted to check to see if anyone else has experirnced this, before I take it out in it/him?.

Keith

You can answer to your question by yourself. All you need is to plug in an additional HDD (for convenience only) and install the best OS Bill Gates ever sold (I mean XP pro, BTW ;-)) on it, and then run a couple of WUs. Of cource, XP need to obtain all latest updates and kosher display driver.

p.s. I hope that your 260s are not combined in SLI mode? :-)

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From Siberia with love!

also, to check between OS's, remove one of the 260s from the vista box and see if the performance for one card improves.

You can answer to your question by yourself. All you need is to plug in an additional HDD (for convenience only) and install the best OS Bill Gates ever sold (I mean XP pro, BTW ;-)) on it, and then run a couple of WUs. Of cource, XP need to obtain all latest updates and kosher display driver.

p.s. I hope that your 260s are not combined in SLI mode? :-)

SLi mode is switched off but Physics is still on.... but that's on for both machines so I don't think that's a contributing factor here...

don't worry , if I find out that it's definately vista, then I'm "downgrading" back to the better performing OS, I'll probably go for a dual boot setup... Vista for gaming and XP for crunching...

also, to check between OS's, remove one of the 260s from the vista box and see if the performance for one card improves.

doing that now... I've got a third Q660 setup XP that the newer 260's going in this morning... if the vista machine still performs badly ans the third XP machine gives better performance, the we know it's vista....

I posted this to see if this was a known "issue" or not...

BTW we've been discussing this on our team forum .... here's some more info that appears to point to vista being the culprit....

here's one of the offending WU's... you can see it polling the Cards in the result text

http://www.gpugrid.net/result.php?resultid=520726

here's one of your Vista WU's (it tke the same time as mine, aound 30k seconds

http://www.gpugrid.net/result.php?resultid=508358

here's one of I'mcrazy's XP WU's

http://www.gpugrid.net/result.php?resultid=521745

around 22k seconds

and my XP box.

http://www.gpugrid.net/result.php?resultid=523590

again around 22k seconds...

Please be aware that not all WUs have the same length. You can judge this by the credit each WU claims, currently it can be 2478, 2882, 2960, 3098 and maybe even other ones. The more credit they claim the longer they take to run. Your two examples on the Vista machine belong to the 3098 family and therefore do take longer, perfectly normal.

To better compare both OS you can look at the timestep/s for similar WU or even better for the same WU.

Kind regards

Alain

Please be aware that not all WUs have the same length. You can judge this by the credit each WU claims, currently it can be 2478, 2882, 2960, 3098 and maybe even other ones. The more credit they claim the longer they take to run. Your two examples on the Vista machine belong to the 3098 family and therefore do take longer, perfectly normal.

To better compare both OS you can look at the timestep/s for similar WU or even better for the same WU.

Kind regards

Alain

Thanks for the info Alain... after digging deeper I picked several WU's that got he same credit - 4611.96

Vista (as dual GPU)
http://www.gpugrid.net/result.php?resultid=525429
# Time per step: 49.819 ms
# Approximate elapsed time for entire WU: 31136.565 s


XP (as Single GPU, same machine as above)
http://www.gpugrid.net/result.php?resultid=511129
# Time per step: 35.191 ms
# Approximate elapsed time for entire WU: 21994.281 s


XP (second machine)
http://www.gpugrid.net/result.php?resultid=508237
# Time per step: 36.328 ms
# Approximate elapsed time for entire WU: 22705.125 s


I'm now more convinced than ever that this is a performance impact through Vista... I have now removed one of the GTX cards from the vista machine... if it speeds up the it's the dual GPU config, if it stays the same then it's Vista, and workout time for "Bill".

Do you use a current driver on the Vista box? Last summer / fall Vista actually seemed to have the faster driver for CUDA, but we went through many iterations since then and I didn't search for hard numbers for a long time.

MrS

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Scanning for our furry friends since Jan 2002

the drivers are only slightly different....

XP v182.08
Vista v182.50

BTW it's looking like the single GPU takes the same time a a dual GPU to process a WU in Vista

will know for sure in the morning...

here's a link to the WU... http://www.gpugrid.net/result.php?resultid=525060

it will complete in about 5 1/2 hours time... it's been running for over 3 hours at present, so not lloking good for "Bill"..

Ni!

OK, final update....

the final two Vista results running as a Single GPU have come in with no improvement

http://www.gpugrid.net/result.php?resultid=525517

# Time per step: 50.491 ms
# Approximate elapsed time for entire WU: 31556.911 s

http://www.gpugrid.net/result.php?resultid=525509
# Time per step: 49.409 ms
# Approximate elapsed time for entire WU: 30880.329 s


So Last night, I re-installed XP-Pro and the Nvidia 182.08 XP drivers, re-inserted the second GPU , the performance has significantly improved, back to the pre-Vista istallation


http://www.gpugrid.net/result.php?resultid=535892

# Time per step: 36.788 ms
# Approximate elapsed time for entire WU: 22992.516 s


http://www.gpugrid.net/result.php?resultid=536393

# Time per step: 36.638 ms
# Approximate elapsed time for entire WU: 22898.849 s


so this can only be down to two things

Vista Home Premium 32bit
or
NVidia Vista 182.50 Drivers

I really hate to muddy the waters here, but have you tried linux yet? ;-)

I'm running 64-bit SuSe 11.1, but I can't compare times with you, as I only have a 9600 GSO.

Since you're in a "OS changing mood", why don't you try a Linux partation on your drive and give it a whirl...

Mike Doerner

Lol did you disable the fancy graphics under performance ;)
I can tell you vista can perform near XP speeds if you turn those fancy graphics off these are the ones slowing you down considerable.
on Win 7 its another matter if it will be as what i am testing now, it seems until now the outperform xp in some projects, without turning of all the graphical extra's, mind you i mean the normal vista alike look.
Not the Aero interface if you run this be certain to loose a lot of performance on your GPU.
I still think linux has to grow out of the "Nerds" stage although my recent version come near easy as windows, but if anything fails ......
We still need too much actions on the prompts, and in failures nothing else then prompts. So for normal people thats too much.

I've played around with Wubi ubuntu, not bad, but I need a good reason to "get me off XP"... I do have a couple of Macs, and to be honest prefer the MAC gui to anything else....


Keith

I didn't know that you could switch off the fancy stuff!!


did a quick search and found this.... http://www.petri.co.il/quickly-turn-on-off-aero-theme-in-windows-vista.htm

but seeing as I'm back on XP now... I'll think I'll stay here....

Wouldn't the GUI only matter if you use the machine interactively?

MrS

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Scanning for our furry friends since Jan 2002

So why don't you d/l Dotsch/UX and put it on a 4 GB memory stick? Boot off the USb and viola! You're crunching! It might be tight with Nvidia drivers though. You can always go to OpenSuSe like me....

http://www.dotsch.de/boinc/Dotsch_UX.html

DOH! CUDA isn't supported on this verstion of the distro, drat! Oh well, you're stuck with a full-blown disrto for now.

Mike Doerner