I have x2 GTX295 cards but I am not sure if they are working. This is because that the GTX295 has got 2 cards in one (or so I am aware). Therefore a total of 4 gpu cores in my set-up. However SETI only detects 2 of these i.e.:

CUDA devices: GeForce GTX 295 (driver version 18585, CUDA version 1.3, 896MB, est. 106GFLOPS), GeForce GTX 295 (driver version 18585, CUDA version 1.3, 896MB, est. 106GFLOPS)

Shouldn't this list show as 4 CUDA devices and not 2?

After some concerns whilst looking about I came across this thread:
http://boinc.berkeley.edu/dev/forum_thread.php?id=3825
I think my problem is related and I am not sure how this person managed to fix it?

If anyone could help it would be greatly appreciated.

I should also mention that I have updated the drivers and have disabled SLI mode.

I have x2 GTX295 cards but I am not sure if they are working. This is because that the GTX295 has got 2 cards in one (or so I am aware). Therefore a total of 4 gpu cores in my set-up. However SETI only detects 2 of these i.e.:

CUDA devices: GeForce GTX 295 (driver version 18585, CUDA version 1.3, 896MB, est. 106GFLOPS), GeForce GTX 295 (driver version 18585, CUDA version 1.3, 896MB, est. 106GFLOPS)

Shouldn't this list show as 4 CUDA devices and not 2?

After some concerns whilst looking about I came across this thread:
http://boinc.berkeley.edu/dev/forum_thread.php?id=3825
I think my problem is related and I am not sure how this person managed to fix it?

If anyone could help it would be greatly appreciated.

I should also mention that I have updated the drivers and have disabled SLI mode.

Yes you should see 4 devices listed.

From reading the message thread you provided he has removed the drivers and reinstalled as well as editing the registry. He also has dummy plugs on the back of the cards and extended the desktop onto each one. Given you have already done the drivers that leaves extending the desktop, the dummy plugs and editing the registry.

Sorry I can't be of more help as the nearest I have is dual GTX260's and I run WinXP. I have heard that vista needs the desktop extended.

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BOINC blog

Thanks for that.

I have edited the registry and all 4 are working.

At first however it displayed as 3 CUDA devices but when the tasks got rolling it is doing 4 at a time now!

It does seem to take up alot of CPU 13-30% and under task manager there are 8 threads running under the CUDA name (although 4 tasks running in the manager)...

Well actually now that I have rebooted computer everything messed and after some more registry editing and messing around I reinstalled the drivers and left it as that. Too much hastle then it's worth in my opinion.

At one point I had all tasks running but it seemed that it would do 2 at a time and switch to the other 2 after a few seconds or so.

I can't understand why it worked great for all that time until I rebooted.

Go back into display settings. I suspect that your desktop has reverted back to being shown only on your main monitor. You may need to extend it to your secondary monitor again after the reboot. Then you will need to stop and restart BOINC.

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You need to disable SLI and turn off "use multi GPU mode" in the nVidia configuration utility.

I have one GTX295 and it wouldn't run two MB workunits until I did the above tweaks.

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Since I'm seeing the exact same Problems with the 185.85WHQL both under Win 7 RC 64bit and Vista 64bit, I guess it's a driver Problem.

I'll try attaching 2 Monitors now, because otherwise I'm completely out of Ideas.

Those dummy plugs or Monitors attached appear to be the only reliable workaround - and I tried hard over several days to get BOINC to recognize my Dual GTX295 my 4 GPUs.

Ironically, WinXP 32bit and BOINC 6.6.20 32bit does recognize all 4 GPUs right from the start with the 185.85WHQL Driver. Unfortunately, having some 3.5GB of Video RAM stealing RAM for the upper PCI address area badly screws this 32bit OS, thus it can only run one GTX295.

The closest I ever got to get 4 GPUs running with Win 7 64bit or Vista 64bit was the V10a Team Mod - unfortunately is isn't smart enough to limit launching Tasks i.e. for 4 CPU cores and 4 GPUs; instead it can easily end up running 6 or more tasks on the CPU while running only 2 (or less) Tasks on the GPUs which may end up running idle, all by pure unlucky draw.

This whole thing has been literally driving me nuts, having some quite costly hardware sitting around unused :(

-- edit --

Oh well, after installing a 2nd Monitor onto the other Card, the screen now stays black unter Vista64, even switching to onboard IGP doesn't help once Vista64 is up and running (which it does in the background).

I think I'll scrap Win7 RC 64bit & Vista64 and go with one card per System with XP32, at least that's working without the incredible pain...

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Since I'm seeing the exact same Problems with the 185.85WHQL both under Win 7 RC 64bit and Vista 64bit, I guess it's a driver Problem.

I'll try attaching 2 Monitors now, because otherwise I'm completely out of Ideas.

Those dummy plugs or Monitors attached appear to be the only reliable workaround - and I tried hard over several days to get BOINC to recognize my Dual GTX295 my 4 GPUs.

Ironically, WinXP 32bit and BOINC 6.6.20 32bit does recognize all 4 GPUs right from the start with the 185.85WHQL Driver. Unfortunately, having some 3.5GB of Video RAM stealing RAM for the upper PCI address area badly screws this 32bit OS, thus it can only run one GTX295.

The closest I ever got to get 4 GPUs running with Win 7 64bit or Vista 64bit was the V10a Team Mod - unfortunately is isn't smart enough to limit launching Tasks i.e. for 4 CPU cores and 4 GPUs; instead it can easily end up running 6 or more tasks on the CPU while running only 2 (or less) Tasks on the GPUs which may end up running idle, all by pure unlucky draw.

This whole thing has been literally driving me nuts, having some quite costly hardware sitting around unused :(

-- edit --

Oh well, after installing a 2nd Monitor onto the other Card, the screen now stays black unter Vista64, even switching to onboard IGP doesn't help once Vista64 is up and running (which it does in the background).

I think I'll scrap Win7 RC 64bit & Vista64 and go with one card per System with XP32, at least that's working without the incredible pain...

Did you go into the NVidia control panel and extend the desktop onto the second monitor?
An alternative to the second monitor with the 185.85 drivers may be to ensure that PhysX is enabled (but not SLI) - but that may just be with CUDA 2.2.

F.

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I didn't have the chance anymore, as the Driver did something upon detecting the 2nd Monitor automatically.

Whatever it was, it went black screen and couldn't be revived to show the Desktop anymore, regardless of Monitor and where it was plugged into (even after re-enabling the IGP; after installing its driver - the System gave a black screen again).

I may try Safe mode and other stuff tomorrow but as usual - it costs time again and prevents advancing (something that happened way too often the last week)

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I didn't have the chance anymore, as the Driver did something upon detecting the 2nd Monitor automatically.

Whatever it was, it went black screen and couldn't be revived to show the Desktop anymore, regardless of Monitor and where it was plugged into (even after re-enabling the IGP; after installing its driver - the System gave a black screen again).

I may try Safe mode and other stuff tomorrow but as usual - it costs time again and prevents advancing (something that happened way too often the last week)

Hmmmm. Your power supply is man enough for the job??

F.

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Hmmmm. Your power supply is man enough for the job??

F.

Enermax Revolution85+ 1050W... that should be more than sufficient.

I restored the display configuration via Safe Mode and again attached a second monitor (this time lowering the Resolution and more carefully setting things up).

Result : no change

BOINC 6.6.20 (both 32bit and 64bit) still sees only 2 GPUs after being point blank installed from scratch.

At this time I have to assume that there is a significant bug in the 64bit 185.85WHQL Driver (or elsewhere) that prevents BOINC from properly detecting all GPUs on dual GPU cards (the Driver apparently reports only one of the GPUs per card via CUDA).

Installation of the lastest CUDA 2.2 Toolkit did not change anything either.

The only thing left for me to do is to remove the 2nd GTX295 from all Systems (once again) and accept that some 1500$ were a wasted investment.
I'm better off putting each GTX295 into a 32bit WinXP system due to these issues (I'm way behind timeline already so any further fiddling with this major pain in the arse is out of the question :p )

For me, the Dual GTX295 has proven to be a complete No-Go at this time and I don't have the time to wait for a new Driver.

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Really don't understand what's happening here. I'm running Vista Home Premium x64 with one GTX295 without any problem. The only thing I can think of is that I found the monitors (or dummy plug) do need to be attached to different connector types on the GTX i.e one DVI and one HDMI.

F.

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There has to be a solution. If you look at the top participants, most of them are running multi GTX 295 rigs. You might look there and PM one that has a set up similar to yours and ask how he's doing it. One other thing that I'd try, is running the new memtest tool on your cards to see if one is defective. It's entirely possible that one is bad. I recently had to RMA one card for giving erroneous results, but it would also cause random issues like not showing the POST screen while booting and causing slow booting, and the desktop would not remain extended to it. The actual video display and graphics on it worked fine, though. Go figure.

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Really don't understand what's happening here. I'm running Vista Home Premium x64 with one GTX295 without any problem. The only thing I can think of is that I found the monitors (or dummy plug) do need to be attached to different connector types on the GTX i.e one DVI and one HDMI.

F.

Running one single GTX295 never has been a big Problem for me (except under Windows 7 RC), it's two of those combined that cause all the Troubles.
For one GTX295, I also did not need any monitor plugs or alike - it just ran as advertised out of the box (at least with the Palit brand cards I got).

@Bad Actor

I know and that's what motivated me to keep trying.
But eventually, my time for experiments and failures simply ran out.
Now I need reliable working configs and a single GTX295 is all I can get to run, despite many years of experience with BOINC and its .xml tweaks.

Bottom line :
One dual GPU card - no sweat. It becomes interesting when 3 or more GPUs come into play and that's what caused me more than one grey hair ;)

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Really don't understand what's happening here. I'm running Vista Home Premium x64 with one GTX295 without any problem. The only thing I can think of is that I found the monitors (or dummy plug) do need to be attached to different connector types on the GTX i.e one DVI and one HDMI.

F.

Running one single GTX295 never has been a big Problem for me (except under Windows 7 RC), it's two of those combined that cause all the Troubles.
For one GTX295, I also did not need any monitor plugs or alike - it just ran as advertised out of the box (at least with the Palit brand cards I got).

@Bad Actor

I know and that's what motivated me to keep trying.
But eventually, my time for experiments and failures simply ran out.
Now I need reliable working configs and a single GTX295 is all I can get to run, despite many years of experience with BOINC and its .xml tweaks.

Bottom line :
One dual GPU card - no sweat. It becomes interesting when 3 or more GPUs come into play and that's what caused me more than one gray hair ;)

It's going to be a while before I can get a 2nd GTX295 as I need a bigger psu(1050w) and a bigger 750GB hdd to replace two smaller ones(150+250) due to the way My main hdd sata cable interface is(the drives edge connector is broken off inside the cable, Thanks WD, About the only thing keeping the 150 going is the gold fingers and Me being very careful) and the way the sata ports face(up towards the bottom of the 295, sigh).

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

...the drives edge connector is broken off inside the cable, Thanks WD, About the only thing keeping the 150 going is the gold fingers and Me being very careful...

I had to scrap a HD a while ago for the very same reason. Bit of a design flaw methinks.

F.

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...the drives edge connector is broken off inside the cable, Thanks WD, About the only thing keeping the 150 going is the gold fingers and Me being very careful...

I had to scrap a HD a while ago for the very same reason. Bit of a design flaw methinks.

F.

It's still under Warranty and I mean to get It replaced under warranty as It's a well known defect in these 150GB Raptors, I have a 250GB Seagate sata hdd and It has never done this, But It's no speed demon either.

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

I can confirm 2 cards = no prob

but...three or more = severe splitting migranes

*rolls eyes*

Also have found windows detection very sesitive to voltage differentials and various things including video cards or temp sensors won't report when too far out of spec. My three card machine won't even crunch with stock bios settings and cards fully utilized. Bare minimum need to slightly overvolt ram and Nforce's. Not sure if NB overvolt was required. Also overclocks that are near limit and crunch boinc CPU fine will run CPU+NB hotter when crunching cuda instead, ie I assume harder calculations with cuda app.

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"The most exciting phrase to hear in science, the one that heralds new discoveries, is not Eureka! (I found it!) but rather, 'hmm... that's funny...'" -- Isaac Asimov

I installed Windows XP x64 to try it. And well it detected the 4 GPUs without messing about with registry etc and actually run on all four at one point. That was after lots of updating the sceduler request because it had no work available - apparantly.

And well now, for some reason it has decided to go on my CPU instead of CUDA without me 'allowing' it in preferences.

So I'm lost at this point.

Thanks for the replies.