I have just upgraded my i7 which had 2*BFG GTX275's to 2*BFG GTX295's with 1792MB GDDR3 memory.
Boinc used to see the 275's as having 123 Gflops however the 295's are only showing 106 Gflops.
I have upgraded to the latest Nvidia driver.They are not performing as well as the 275's.
Any help with setting these 2 cards up would be helpful.

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I have just upgraded my i7 which had 2*BFG GTX275's to 2*BFG GTX295's with 1792MB GDDR3 memory.
Boinc used to see the 275's as having 123 Gflops however the 295's are only showing 106 Gflops.
I have upgraded to the latest Nvidia driver.They are not performing as well as the 275's.
Any help with setting these 2 cards up would be helpful.

by 'not performing as well' do you mean taking longer to do a workunit? or are you just going by the gflops rating?

are both the 275 and 295 cards stock 'reference' and not overclocked? is boinc seeing 4 gpus? or is it seeing 2? you need to have 2 in number_of_gpus file like you did for the 275s, and in app_info.xml set the cuda number of procs to 2:

<coproc>
<type>CUDA</type>
<count>2</count>
</coproc>


so it knows to use both processors in each package.

also is your power supply sufficient? one other thing to check is some mobos when set to auto for pci-e bus frequency tend to go off when encountering 2 processors in a slot. might want to fix that to 100mhz. those are the only things i can think of offhand that may cause a bit of slowness besides gpu temperature not counting the device speed differences. keep the fans high. i understand the 295 runs hot compared to the 285. i keep my 285 max 70c under max load so just kicking out from nowhere i would guess to try to keep the 295 from going much above 80c, lower if it is possible.


these are all good things to check over. i think you are ok though and i do not feel that things are on shaky ground at all.

according to this chart:

http://en.wikipedia.org/wiki/Comparison_of_NVIDIA_Graphics_Processing_Units

the 295 runs approx 1788 gflops while a 275 is 1010 gflops. bearing in mind the 295 runs slightly slower clocks, dividing that gross total by 2 gives approx 894 gflops per processor, which is expected. even slightly slower than a single, the fact that 2 work at once gives far greater performance. so once you can look at your process listing and see 4 cuda drivers 2 feeding each device you can count on processing approx 2x more units per hour than the 2 275s can. to give you an idea, my tesla rates 933 gflops according to the chart and boinc double precision gflops only rate it at 74gflops. so i think you are in the ballpark with your 106.

in looking at your boinc gflops reports my guess is it is accurate and i would not worry about that but rather make sure you have all 4 processors churning out work units. if one of those cards also runs your desktop, i would set your preferences to use 6 cpus instead of 8 (or maybe use 7 but i think that is pushing it), and set the avg ncpus and max ncpus in app_info.xml to a starting point of 0.5

<avg_ncpus>0.500000</avg_ncpus>
<max_ncpus>0.500000</max_ncpus>

and then over the long term, waiting several days to see results of a change, adjust it up and down to give you max production. by limiting the number of cpus used to 6 i think you will find your average rac will increase higher than if you ran all 8 since you can run the 6 cpus at 100% usage for boinc and still leave enough 'gopower' to run your desktop and feed the gpus with the remaining 2.

those are my thoughts on it anyway.. unfortunately i could not afford a 295.i was lucky to get the 285, however my next build next year is going to include the 295s.

once you get it sorted out you have quite a supercomputer there. :)

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I have just upgraded my i7 which had 2*BFG GTX275's to 2*BFG GTX295's with 1792MB GDDR3 memory.
Boinc used to see the 275's as having 123 Gflops however the 295's are only showing 106 Gflops.
I have upgraded to the latest Nvidia driver.They are not performing as well as the 275's.
Any help with setting these 2 cards up would be helpful.

In what way are they "not performing as well as the 275's"? I assume you are now crunching 4 x CUDA WU's at a time instead of 2?

BTW, with apologies to Chuck, don't set the app_info <count> to "2". This is the number of GPU's required per WU so if you set that value to "2" your BM will show "0.xx CPU, 2 GPU" against each CUDA WU.

F.

[edit]106 GFlops is what Boinc sees for a stock, non-overclocked, GTX295. If you are feeling adventurous you can turn the wick up with EVGA Precision or RivaTuner or similar but do[ watch the temps. With the default automatic fan settings the temps in the 295 get up to 100C before the fan gets up to 100% and all that heat is being dumped into your case to affect other components. [/edit]

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@ Chuck Thank's for your indepth reply,lots of points to take in.
These cards are running stock as they have only just been fitted.
I have checked in device manager and both 295's are showing however
using EVGA it looks like it can only see 1 card,or 1gpu.

@Fred I am only processing 1 wu's at a time so only 2 gpu's running.
I don't know whether it is 2 gpus on 1 card or 1 gpu on each card.
I have never had a problem with setting up my other cuda cards, but
could it need a dummy plug or are there settings in the nVidia control
panel that need to be changed.

BTW Everest shows the 2 295's but only 30/240 Microprocessor/Cores I would
have thought this might be duplicated

Dave

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@ Chuck Thank's for your indepth reply,lots of points to take in.
These cards are running stock as they have only just been fitted.
I have checked in device manager and both 295's are showing however
using EVGA it looks like it can only see 1 card,or 1gpu.

@Fred I am only processing 1 wu's at a time so only 2 gpu's running.
I don't know whether it is 2 gpus on 1 card or 1 gpu on each card.
I have never had a problem with setting up my other cuda cards, but
could it need a dummy plug or are there settings in the nVidia control
panel that need to be changed.

BTW Everest shows the 2 295's but only 30/240 Microprocessor/Cores I would
have thought this might be duplicated

Dave

You are running the 190.38 drivers so I would have expected that a dummy plug would not be needed. My experience is with only one GTX295 but that build seemed to get around the requirements for fiddling with SLI etc. to get the 2 GPU's seen by Boinc.

Boinc is currently reporting 2 x 295 GPU's - it should be showing 4 GPU's for 2 x GTX295. As a starter, I would try adding (or editing) cc_config.xml with the use_all_gpus option e.g.

<cc_config>
  <options>
      <use_all_gpus>1</use_all_gpus>
  </options>
</cc_config>

If that doesn't work, then it depends which version of the GTX295 you have. If it is like mine and has both HDMI and DVI connectors then a dummy plug would be worth a try in one of the 295's to see if that will get both GPU's recognised.

F.

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Hi Fred
I have the newest version BFG GTX295 with 1732 MB memory.
I will edit my cc_config and see if that helps.
I have taken the sli bridge from between the to cards and have
set in the nVIDIA Control panel do not use multi gpu mode that is
supposed to allow each gpu to drive a monitor and so should be seen
seperatly.
Dave

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BTW, with apologies to Chuck, don't set the app_info <count> to "2". This is the number of GPU's required per WU so if you set that value to "2" your BM will show "0.xx CPU, 2 GPU" against each CUDA WU.

hmm interesting. thanks. i was going by my own experience with a single gpu card when trying to get boinc to properly work with 2 devices (was beating a dead horse since there are only 2 or 3 versions of boinc to work properly with 2 devices in linux). when i set that to 2 it fed 2 workunits to the same device. must behave differently with a single gpu per device.

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Hi Fred
I have the newest version BFG GTX295 with 1732 MB memory.
I will edit my cc_config and see if that helps.
I have taken the sli bridge from between the to cards and have
set in the nVIDIA Control panel do not use multi gpu mode that is
supposed to allow each gpu to drive a monitor and so should be seen
seperatly.
Dave

On reflection, I suspect what is being seen is the 2 x GPU's on one of the GTX295 cards. You may need a monitor or a dummy plug connected to at least one of the ports on the second card.

If this is not the case, then a monitor or dummy plug connected (temporarily) to the HDMI output on each card may be necessary to get all the GPU's registered. Once they have been found then it doesn't seem to matter.

F.

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Fred Thanks for the info.
I tried as you said a monitor on the 2nd 295.No joy.
The PSU in the rig that the 2 old GTX275's was going into was not big enought to run them both so I had to get a new PSU yesterday.
I spent last night putting the new bigger PSU in the i7 which has the 2 BFG GTX295's in.
After a reboot I checked in Device Manager and under Display adapters it shows 4 NVIDIA GeForce GTX 295's.
So far so good.
I then checked using Everest and EVGA and they both record having 4 GPU's.
Problem is that when I run Boinc 6.6.37 it only sees 2 GPU's.
I have even started Boinc with another monitor attached to the 2nd card but still no joy.
Any ideas.
Dave

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... Any ideas.
Dave

It shouldn't make any difference with the 190 drivers, but you have got SLI disabled for both 295's in the Nvidia control panel?

I'm on client site today so posting of any further ideas may be intermittent until this evening.

F.

[edit]You could see what Boinc says with just one 295 installed and then the other; i.e. is Boinc seeing both GPU's on one 295 or one on each?[/edit]

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Understood Fred
I tried that and Boinc sees both gpu's on 1 card.
Using Everest the second cards gpu's running cooler.
Dave

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Understood Fred
I tried that and Boinc sees both gpu's on 1 card.
Using Everest the second cards gpu's running cooler.
Dave

You're now getting to the limit of my experience - I have (when it comes back from RMA) only one GTX295 :(
So, if you take out the card that is being recognised by Boinc, will Boinc recognise the 2 GPU's on the other 295?
Maybe someone who is running multiple GTX295's could chip in with some ideas here?

F.

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Thank's Fred
I will try that.Just a pain to get them out the rig lol

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Hi Fred
I have tried what you suggested and both cards work ok with Boinc.
I have reinstalled both cards and they are seen by Vista's Device manager and show 4 GPU's.EVGA and Everest also see both sets of 295's both report 4 GPU's.
It is only Boinc that can only see 1 card.
I have also attatched a monitor to the second 295 and run the system but Boinc still does not see it.
Anything else I could try.
To anyone else reading this.If you have any ideas please feel free to chip in.
Thank's in anticipation.
Dave

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What about "extending desktop"? I have no CUDA device, but I think that was mentioned in several threads.

Gruß,
Gundolf

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Computer sind nicht alles im Leben. (Kleiner Scherz)

SETI@home classic workunits 3,758
SETI@home classic CPU time 66,520 hours

I have tried that and it works ok so the second card is seen and works ok.
Dave

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Hi Fred
I have tried what you suggested and both cards work ok with Boinc.
I have reinstalled both cards and they are seen by Vista's Device manager and show 4 GPU's.EVGA and Everest also see both sets of 295's both report 4 GPU's.
It is only Boinc that can only see 1 card.
I have also attatched a monitor to the second 295 and run the system but Boinc still does not see it.
Anything else I could try.
To anyone else reading this.If you have any ideas please feel free to chip in.
Thank's in anticipation.
Dave

Sorry Dave, I have totally run out of ideas. One last thought - when you say you have attached a monitor to the second 295 and run the system, you do mean that you have run the system with 2 monitors connected and the desktop extended across the 2 monitors? If that is, indeed, your meaning then I hope someone else can come up with something helpful.

F.

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Yes Fred both monitors work extended desktop.
I think tomorrow i will remove both cards and put an older type card
in the system amd remove the drivers,then try a new install of the cards and drivers.
Others have them installed ok so it must be me being a bit on the noob side as
far as these new fangled things go lol
Dave

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Yes Fred both monitors work extended desktop.
I think tomorrow i will remove both cards and put an older type card
in the system amd remove the drivers,then try a new install of the cards and drivers.
Others have them installed ok so it must be me being a bit on the noob side as
far as these new fangled things go lol
Dave

Might be a bit "left-field" but I wonder if a downgrade of Boinc, try it, and then re-upgrade might be worth a try? A lot less trouble than swapping the drivers and it might just have an effect...

F.

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O.K. Will try that first.
Am I likly to loose any tasks in the cache?

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