Hi,my 4 GTX295s runs 1 task each at time,I know they might run 4 tasks each,2 each 295 processor.
I loaded all the video outputs,extended to two desktops each card,and the OS correctly reconyze 8 GTX295 for 4 cards.
The Boinc manager see 4 GTX295
What can I do more?

max

Hi Max,
which computer are your referring to?
You don't seem to have a 4 GTX295 machine.
http://www.gpugrid.net/hosts_user.php?userid=28232

gdf

I have two 3x GTX295 PCs and I'm about to place the fourth card back inside each,I'm just waiting for two 1500W PSs as I suspect the actual 1350W PSs are not enough as I got a lot of "error while computing" when they were loaded with 4 GTX295 cards.

My suspect is I'm anyway running 50% of those cards capability as the OS reconize 2 times the cores respect to the Boinc manager?

max

Hi Speedmax, have you switched off SLI for those machines and just to verify, you did not install the SLI bridge connectors, right ? What powersupplies are you currently using and which ones did you order ? (the exact brand and type please). I am also curious, which motherboard are you using ? regards, H.

---

Join team Bletchley Park, the innovators.

Hi H.,
yes neither SLI on or bridges.
I actually use Coolmax 1350B PSs and I ordered two Silverstone ST1500 for the 4 GTX295 cards PCs.
I use all ASUS P6T7 WS SuperComputer but one P6T6 WS Revolution.

max

Are you running 1 task per 295?

MrS

---

Scanning for our furry friends since Jan 2002

Hi, the Silverstone will really *just* do at 25 A on 12 V each. the Coolmax can only barely support 2 to 3 cards because of the amperage on the 12 volt lines. 20 A on a 12 V line is not enough. The Asus bord looks like fun :)

@ Mr S: From his machine overview I would be tempted to deduce that BOINC only sees one GPU per GTX295.

Yes,I'm just running 1 task each 295 card,while the OS detect 2 GPU each card correctly,the Boinc manager only detects one.
What could I try next?

About the PS I choosed the Coolmax 1350B because suggested on the NVIDIA site to feed 1 FX5800 + 3x Tesla cards.
Next week I might receive the Tesla cards to make this try!

max

I just realized, you now have two spare powersupplies, so you can hook up the Coolmax to two gtxes using a 25 A line on the 8-pin *and* one 20 A line on the 6-pin each. You can then do the same with the Silverstone cables, using TWO 12V connections for each GTX295, so one 25 A line for the 8-pin and another different 25 A line for the 6-pin.

You need to slave the Coolmax to the Silverstone using a special motherboard slave plug, or build a slave switch yourself. Do not switch this by hand, you may damage the cards. I use four 700 W powersupplies for my system with three slaved powersupplies to my master supply which also feeds the motherboard.

You might try to fully power only two GTXes and see if you now get 4 GPUs in BOINC with two cards installed. You can try this even with the Coolmax ps.

---

Join team Bletchley Park, the innovators.

Wow! I will check if there is something ready to do this first!

max

Is multi-gpu mode turned on in the nvidia control panel?

Bob

I get that option for one card plugged-in only instead of the "enable SLI" option.

max

Hi H.
Now one three 295 cards pc runs 4 GPU on 6 instead of 3,so it's a power problem!!!
As you said must use multiple PSs to feed 4 cards!!
I hope the 1500W will be good for three cards at least! I will make up a third PC for the remaining two cards eventually.


max

Hi Max, very good ! congratulations.

---

Join team Bletchley Park, the innovators.

One more problem!

Why the OS doesn't reconaize the 4th FX5800 card?
Again a power lack problem? I use the same 1350W PS I use to feed 1 FX5800 + 3x FX3800 in another pc.
And more that 1350W PS is the one suggested by NVIDIA to feed 1x FX5800 + 3x TESLA.

max

Did you see here how tricky it is to get 4 GTX 295 running?

MrS

---

Scanning for our furry friends since Jan 2002

Why the OS doesn't reconaize the 4th FX5800 card?
max

I do not know, unfortunately.

:)
I will try to insert better the 4th card.....as I will find my hammer

max

Thank you MrS!
I see that fine H. work!

H., following your hints I joined two 1350W PSs,but now I see,from the suggested thread, its not easy anyway!!

The PC perform 4 task with 4 cards and make lots of errors.

I will change the driver to the one you suggest and try again.
Maybe Windows 7 is not the right OS?
I have a Vista 64bit but I guess it would be about the same?
I might receive XP 64bit shortly,in this while I will downsize to three cards.

max

Wher to find the 178.13 driver,I can find back to the 181.71 only on the NVIDIA site?

max