Dual 9800gtx and gpu2 questions...

[jonspd]

Ok I've got my hand on another card so I have to put said card on my secondary rig and gonna have to run 2 x 9800gtx's in my primary. I really don't want to but just wanting to know a few things. If I run sli for some benches I cant run gpu2 while in sli correct?

both are evga, one is a stock clocked and the other is a ko should I just match the cards clocks with rivatuner or evga persicion?



card1
Core Clock Speed 675MHz
Memory Clock Speed 2200MHz
Shader Clock Speed 1680MHz

card2
Core Clock Speed 738MHz
Memory Clock Speed 2250MHz
Shader Clock Speed 1836MHz



or should I flash both the the SC speeds of


Core Clock Speed 700MHz
Memory Clock Speed 2200MHz
Shader Clock Speed 1728MHz


want to try and get the best PPD out of these on my primary.

[StaTek]

Precision was made by the same guy as Rivatuner and is basicallly a stripped down version for beginners. Precision is only for gpus in SLI. If they are not in SLI and you use Precision, you are only doing the changes to one gpu. So my advice is to use Rivatuner....and make sure you bump up the fan speed on each adapter.

[jonspd]

Yea I did that before used percision for one and rivatuner for the other still wondering about the clocks and if they both need to be at the same speed or same bios to work without taking a PPD hit.

[torin3]

Yea I did that before used percision for one and rivatuner for the other still wondering about the clocks and if they both need to be at the same speed or same bios to work without taking a PPD hit.

Nope, they don't need to be at the same speed for GPU2. I've got a rig with 4 8800 GT cards, and they are all running at different speeds, and they take no hit from one of the other cards running at a different speed.

Just remember you need a monitor plugged in, or a dummy plug on the second card for it to keep the Rivatuner settings on reboot. (Doesn't always hold in my experience, but most of the time it will.)

[ChinStrap]

Nope, they don't need to be at the same speed for GPU2. I've got a rig with 4 8800 GT cards, and they are all running at different speeds, and they take no hit from one of the other cards running at a different speed.

Just remember you need a monitor plugged in, or a dummy plug on the second card for it to keep the Rivatuner settings on reboot. (Doesn't always hold in my experience, but most of the time it will.)



i dont have a monitor plugged into 2 of my g92's and @ restart i do need to do in a reset clocks. on the cards plugged into monitors the clocks do not need to be reset.

[jonspd]

I have a 2405 and 2005...

So for each version each ppd will very alittle dude to shader clocks but if I clock them the same they will keep equal PPD?

[ChasR]

My multi gpu rigs produce the same ppd from identical cards running at the same shader clock regardless of PCIe speed.

[jonspd]

again so card A clocks are higher then B will A outproduce B and will B take a hit? or will both card produce at 100%

[torin3]

again so card A clocks are higher then B will A outproduce B and will B take a hit? or will both card produce at 100%

Both cards will produce at 100% of what their clocks should deliver.

Say:

A & B are both at 1500Mhz on the shader clock.

A=5100 PPD
B=5100 PPD

A is then bumped up to 1700Mhz on the shader clock. B is left alone.

A=5300 PPD
B=5100 PPD

A is then bumped up to 1900Mhz on the shader clock. B is left alone.

A= 5500 PPD
B= 5100 PPD

A is then dropped to 1300Mhz on the shader clock, and B is bumped up to 1900Mhz on the shader clock.

A= 4900 PPD
B= 5500 PPD

If you get an unexpected drop in PPD, something else is going on. Like when I forget to set the VM's affinity to 0/1/2 after a reboot.... :bang head

[jonspd]

Ok so then as long as there the same core clocks don't affect anything but PPD.

you using 2xvm's and 1gpu2 client or 2gpu2 clients?

[torin3]

Ok so then as long as there the same core clocks don't affect anything but PPD.

Not core clocks, shader clocks. Shaders are the only thing that affect PPD. Unless you game, there isn't much point with messing around with the Core and Memory clocks. You could even underclock them to reduce power draw.

you using 2xvm's and 1gpu2 client or 2gpu2 clients?

My home computer is is 2 VMs and 2 GPU2 clients. I use the environtmental variable to force both cards to use core 3, and I set the 2 VMs to each use cores 0/1/2. The PPD on the card that my monitor is hooked into drops down when I'm doing stuff like playing Youtube videos or simple games. When it is idle though, they are pretty much the same. I do turn it off for 'real' games like Portal.

[jonspd]

correct it was to early in the morning :D I did under clock my 2ndery

core shader clocks? lol


cool nice cruncher was just wondering

[torin3]

correct it was to early in the morning :D I did under clock my 2ndery

core shader clocks? lol


cool nice cruncher was just wondering

Thanks. My 3 personal rigs are my home computer (with the 2 VM/2 GPU2), my work computer, which runs 4 GPU2 clients, all 8800 GT cards with mixed memory sizes. I get about 20K PPD out of it. And my home media server, which has 2 VMs and an 8800 GTS (640M - G80), though I'm thinking about getting a 9800 GX2 for it. I also have my former roomate running an 9800 GT card (no VMs on it, as she isn't that much of a folding junkie, and a one click client is easy to deal with.) And a friend has promised to run it on his computer that I built for him, with an 8800 GT, though he hasn't actually started yet. I should, if everything runs right, get about 50K PPD.


Whoops...sorry, didn't mean to threadcrap...