trouble with sli :(

[chipps101]

howdy folks, i was wondering if anyone familiar with sli could look over these screens and maybe give me some help as i don't think it is kicking in properly

the system it is on is -
dfi sli-dr skt 939
x2 4200 @ 2530
2.5gb ram
2 x 8800gt's

basically i built this system as a plaything as i wanted to try sli and i had a few bits lying around that i thought i could use and try and see how close i could get to my main rig for about the cost of my gfx card

main rig score


at first all went well with 2 7800gtx's

7800gtx single


7800gtx sli


so as you can see sli scaled ok and i got a nice boost with the 2 cards

but then i got 2 8800gt's to try and see if i could get close to the main rig

8800gt single


8800gt sli


as you can see my score went down with 2 cards

here are some screens of my settings -






i have tried all the multi gpu setting and sli settings to no avail



so does anyone have any ideas ? do i have a setting wrong ? is the pcie slots running at 8 speed crippling me (it shouldn't) ? anything else i'm not thinking off ?

any help would be much appreciated

 

[Rroff]

Are you running the tests in windowed mode? doesn't always give the best results for SLI compared to fullscreen.

Usually you only get worse results if your forcing SLI mode with the wrong settings or in very rare cases where the CPU overheads cost more than the framerate gains - not usually an issue with a decent CPU.

 

[chipps101]

i know the x2 4200 is slow nowadays but i was hoping it would be fast enough oc'd to 2.5 just to play around with.

i thought these kind of tests would be gpu limited with low cpu usage.

and 3d mark 06 is showing a slight decrease in performance also and that runs fullscreen

 

[Rroff]

3D Marks 06 is heavily CPU dependant - with a X2 4200 you won't see any increase from SLI its probably not even enough in that to max out a single 8800GT.

 

[chipps101]

i thought it was only the cpu tests bit that was cpu heavy in 3d mark 06

i know that tropics gives similar results even with much faster cpu's so thats why i focussed on that test.

same test with an e2180 @3ghz with a 9800gt green running at slightly slower clocks, so the gpu is slightly slower but the cpu is around 40% quicker and the score isn't to far ahead.



do you think my x2 4200 @ 2.5 just isn't fast enough to run the two cards ? if you notice in the sli screen shots the cpu load isn't getting anywhere near 100% for the cards but it is using both.

*edit - ooops wrong cpu lol thats an am2 athlon x2 6000 @ 3ghz so not that much quicker than the x2 4200 @ 2.5 maybe 20% - 25%

 

[Greebo]

i thought it was only the cpu tests bit that was cpu heavy in 3d mark 06

i know that tropics gives similar results even with much faster cpu's so thats why i focussed on that test.

same test with an e2180 @3ghz with a 9800gt green running at slightly slower clocks, so the gpu is slightly slower but the cpu is around 40% quicker and the score isn't to far ahead.

3dmark06 alters with cpu. I had a q9650 running at 4.85Ghz with a super overclocked 5850 and I couldn;t get anywhere near the scores of people running i7 processors even at 4Ghz. Vantage is better for straight gpu scores.

 

[chipps101]

but don't you only get to run vantage once unless you buy it ?

 

[chipps101]

ok i'm officially an idiot tonight

it was cpu limitation lol

i thought how could i check and then had the Doh!!! moment and realised all i had to do was crank up the setting a bit to get it back onto the gpu's

so here is 8800gt single


and here is 8800gt sli


yay it's scaling probably still a little cpu limited but at least the cards are stretching their legs now

but it still aint really catching up to the main rig lol


and i didn't even have the 460 clocked

 

[chipps101]

been testing at even higher resolutions and sli is definatlety kicking in well with the 8800gt's even with such a lowly cpu -

single 8800gt


8800gt sli


its catching up a bit to the main rig but i don't think it will get any closer than this without a quicker cpu as that is my spare monitor maxed out resolution wise.


but that's still not to bad for what is definitely old cheap second hand tech

 

[jorzeh]

Don't be so hard on yourself we can't allways be right can we