SLI Blues

[Alf]

Got 2x 8800GT cards, single card performance was great. Adding a second card however didnt give me any gain in my games or 3d mark score. Granted that UT3 and Bioshock are locked at 60 fps ceiling. And Crysis performance leaves much to be desired. So thinking this is a fluke of sorts, i checked Nvidia control panel, SLI was active, and checked the 3d setting. To my surprise - most newer games (including those mentioned) were running in Single card mode, And there was no option to change it to SLI.

Do you think did something wrong? Or have i run into my CPU bottle neck so soon?

Here are my 3dmark scores, i know they arent the only thing to go by, but this is were i though something is wrong.
7900GT - 7850 marks
8800GT - 14053 marks
8800GT SLI - 14000 marks

 

[muckshifter]

You are a "victim" of market hype ... Unless a "program" has the knowledge to "use" such a thing, you ain't gonna get it to work.


I know of other "gamers" fallen foul of the dual SLi fiasco.

The technology ain't new, its has been around since 1998, I think, when 3Dfx first invented it. We even called it SLI even then, but it meant something different than the SLi of today. SLI doesn't always give a performance benefit.

 

[floppybootstomp]

Alright, this may seem a dumb question but you do have the link cable between the cards fitted don't you?

And yes Mucks, I can remember having 2 grafix cards fitted, didn't make that much of a difference, even then, but it did cost an arm and a leg

 

[Alf]

Yes i do have them linked up with the latest drivers.
Tell me it aint so mucks

by the by, what games are 'SLI', 'Certified'

 

[Alf]

Well mucks, now that i think of it, there are loads of sites that have graphic card reviews (not to mention a few publications) that have SLI performance showing a increase in performance. You tellin me nvidia bought them out? Or what you said is more or less up to personal interpretation?

If anything.... at least i have 2 mini heaters in my computer to keep me warm

 

[muckshifter]

In a nutshell, SLi can be akin to dual-core GPUs ... you get to do two jobs at the same time, or do they?


You'll have to tell me what MB you have ... is it really dual 16 lanes, or, is it one of them ... put two cards in, will only operate at 8 each ... you know that is slower than AGP, right.

Have a look at the spec of, say, the Asus P5N-E SLI ... the SLI graphics cards are forced to share 16 PCIe lanes, so when SLI is enabled the bus is divided effectively creating dual PCIe 8x slots. Sorry, that is slower than AGP 8x

[edit: yes, nvidia bought 3Dfx and their technology ... they may even improve on it one day.]

.

 

[Alf]

I have a Asus A8N32 SLI Deluxe motherboard. Asus says both PCI-e lanes are 16x independently. "In SLI mode, the PCI-e x16 slots work at the full Bandwidth of PCI-e x16 on each slot for a combined bandwidth of x32" , Asus user guide.

I dont mind if i dont get x2 the performance, but i would mind if the second card is doing nothing.

 

[muckshifter]

Jolly good, but I don't know what you were expecting, all I can say is ... they should split the "processing" between themselves.

 

[Abarbarian]

Have you looked at the Guru review test on the card ? you might get some info there .

http://www.guru3d.com/article/Videocards/468/14

 

[Alf]

Ah, thanks Abarb... but it did little to ease my suspisions

I ran the FEAR ingame test with the everything maxed out at 1280x960
They got 96 fps average, I got 100 fps.

In the 3dmark 05 they had a 3000 mark differnce on single card compared to my computer, This is understandable.
But where as thier score increased in SLI, mine didnt change - at least it didnt drop

I think the slight increase in the FEAR benchmark is attributed to newer drivers more than anything. Does anyone know of a guide on SLI? i suppose its best to read up on it.

Thanks guys!

 

[Abarbarian]

Didn't have time to read the article only the first bit but there is stuff about SLI . Ian posted it today in the news section .

http://www.hardwaresecrets.com/article/391

 

[Alf]

Do you think my 2nd 8800GT will kinda go to waste? that is until i upgrade my mobo and proc?

 

[Alf]

Also would updating my bios help? or is it still one of those ' if it aint broke' situations?

 

[Abarbarian]

If you have ASUS Update on that board doing the bios should be dead simple .
Use it to save your old bios first .
Get the lateset bios downloaded to a file from the Asus site .
Put another pound coin in the meter ,or should that be a peso .
Use the Asus Update to put the new bios in from the file you got earlier .
Doing it that way means you don't have to worry about download interupts whilst updateing , which I belive can be a real pain in the .......

You'll have to read up on what the latest bios do before you can make a decision wether or not to update though .

 

[Alf]

Eh, Abarb.... Its Dollars.... I live in the states remeber? NEW Mexico, not Mexico.
Ill Look into it, thanks

 

[Abarbarian]

Same thing , your all jonny foriegners .

 

[Alf]

do you think there may be a performance increase?

 

[Alf]

.... after reading some other forums, i dont think i will update my bios. theres no real reason to since im no going to put in a X2.

Right now i deffinitly think my computer is bottlenecked by the CPU.

 

[Abarbarian]

Sell one of the 8800's and buy an AM2+ board and something like a AM2 4800 or 5000 Black and you'll fly along . Course you won't be able to SLI then .

Sorry couldn't resist .

 

[Alf]

That would be reasonable.... But i aint the one to heed reason