EVGA 7900gt co superclock SLI mode

[Arkane13131]

my system...

3800+ x-2 @ 2.35ghz
1 gig ram
antec SP 500w
7900gt co superclock



I was getting artifacs at stock speeds with my 7900gt co superclock from evga...so i requested crossshipment RMA.

since I have 2 cards here...I figured Id screw with both of em to see what kind of numbers I get.

here are my single card scores...


3dmark05 9438
3dmark06 5295

i know..abit weak but i have dirt cheap ram. underclocking the ram..and overclocking the bus so that they are running at ever so slightly slower than stock speeds..still gives errors..so had to loosen the timings and they dont error now..but kind of a weak score.

now here is the SLI performance numbers....


3dmark05 12253
3dmark06 7864


3dmark05 seems really weak. 3dmark06 just seems ok..nothing spectacular.

so here is the reason for my post...

is my CPU too slow to harness the power?
is my power supply too weak to do the cards justice?
are these scores ok and I am just crazy?
when in SLI mode do these evga 7900gt co superclocks set themselves to stock speeds?

thnx!

 

[TheRyuu]

Set drivers to high performance and make sure all the optimizations are on cause thats you you might be able to get a higher score (and is what everyone else does anyway.

BTW, I'm sure that there's nothing wrong with your cards, screw the RMA and just get some better heatsinks. That little dinky hs on the 7900GT can't cool crap. Get a vf700/vf900/NV Silencer Rev.3 (the second might be a little long, so it'll stick out the back of your case).

And the scores are ok. I get 13770 with my 7900GT's @ 560/850 (1700 effective).

 

[Arkane13131]

well many many many people have had the same problems on EVGA's website and several of them said they tried using different cooling solutions with no benefit. i downclocked the card to stock speeds and it still happend. Its not very frequent tho. it seems its consistent with their first batch of cards, they used for the step up program. eitherway its fun to screw around with SLI for 10 days or so since i have 30 days to return the old card.

hmm your cpu is 250mhz per core faster than mine..which is alot on amd chips. think thats what makes the difference? or do you notice a solid improvement with those memory clocks?

how do your cards run at my card's speed (guesstimate) ?

550/1580(effective)

also...my psu is holding it togeather eh? woo yay 500w antec!
lol...

edit: i dont exactly own the second card...i just have 2 since i RMA 1 with cross shipping for the time being. no money for 700$ worth of video card LoL.

anyway looks like cpu limitation is holding these puppies back...ill be buying a physics card before a SLI graphics card im thinking.

wonder how much better oblivion would run with a physics card..since it seems extremely cpu limited... (between single card and sli i dont physically see a difference and fps seem about 3 faster LoL)

 

[TheRyuu]

Well, do deminstrate something, I ran 3dmark05 with my CPU at 250x8 or 2.0ghz (2000mhz...duh).
I also ran it at your 550/790 clock speeds.
Now I thought 3dmark05 was based alot on GPU, but the results actually surprised me.

I got 10,218 3dmarks, way lower than I would have though.

Now, this is a guess (cause I ran it a little while ago), but I think I scored at least 12,000 at those same GPU speeds with my CPU at 2.5ghz.

Well, I guess it's time to Overclock yours a little more. I'm almost positive you could hit higher.

And for your comment on Oblivion, i don't think it's that cpu limited, seems graphic card limited. All the X1900's play it a tad faster than even 7900GT's in SLI. And a physics card would only help in games that support it.

Edit: Cranked up my CPU speed to 2.5ghz again, score went to 13,673 3dmarks in 05. I also bumped up the memory to 800 (1600 effective) but I doubt that had a big effect (10 more mhz, not that much)

 

[Arkane13131]

thanx for taking the time to test!
i know it sucks to run those same goddamn tests for years lol so i appreciate it alot.

3dmark05 does hit cpu limitations alot more than i ever expected.

i think anandtech's tests were single cards in under different cpus..the effect is ALOT more pronounced with 2. theoretically i could see 2 7900gt superclocks hitting 15000 before the gpu's stop again...but i am an optimist >.> and probably full of it.

and reguarding oblivion..
well im not sure about other people's rig but.. adding 350mhz to my core was a better influence than another 7900gt superclock, so its just a theory really.

I think all those folks with crazy sli results in oblivion ect have like 800$ cpu's or crazy overclocks.

i could get more out of my cpu aswell but the ram just sucks so bad i cant really push it anymore...it starts to become counter productive from 350->400mhz overclock it plateu's. thats what i get for having 1 gig of ram that costs 45$ LoL i also get cpu rounding math issues on 1 core failing Prime95. i am using stock voltage as that scares me more than a standard overclock.

im a poor boy anyway really need to keep things safe..if i did for somereason blow something up -.-; i cant replace it.

thnx again!

edit: goddamn 500mhz on the cpu... = 3100 3dmarks...thats more than my radeon 9800pro used to and then some!

stock 2ghz i score very close to 9000 with 1 7900gt so i got 500marks for 350mhz cpu.
yours is alot more beneficial because of SLI.

if i had the money to own both these cards id do it just so i could look in my case and smile. heh but i dont..again its just a cross shipment overlap that allowed me to toy with em.

i thought that..physics cards would work with all games that use Havok? so oblivion would support it right off the bat?

just wishful thinking i guess -.-;

 

[TheRyuu]

One more thing to help your CPU overclock. Don't be afraid to use a divider on the RAM. You can hit CPU bus speeds of 275 while still keeping the ram at 200ish mhz. Not sure of the divider to use, but performance doesn't drop noticibly with a divider, and a lot of Overclockers (espically the Opty 165 OCer's and the small 9x multiplyer) use the ram dividers very often.

 

[Arkane13131]

hmm thanx ill keep it inmind.. im just very noobish to overclocking... i really dont know anything about it...my mobo automatically seperates the cpu and the ram from the rest of the system...so i just downclocked my ram to 333mhz and upclocked the bus bringing the ram to 190x's 2. the rest of it all confuses me -.-; another reason i shouldnt screw around im thinking.