SLI

[LSPIII]

Hi guys, I have just managed to acquire myself a second 7800GTX which I plan on running in SLI. Got a good deal on it. Is there anything I should be thinking about?

I will be runnning it on the Asus A8N-SLI Premium, so I know that the second PCI-E slot isn't the full 16x. I run XP x64 and have the latest drivers from the nVidia website already. Is there any games out there which could have an issue etc. Really, I'm just looking for some info on it!

Cheers

 

[LSPIII]

make sure you got good psu and a good working bridge for the cards

I have literally just opened the static bag containing the bridge that came with the motherboard so that should be fine.

Power supply... How do I put this... Bear trap... Sounds about right. Fell in to a bear trap by purchasing the Hiper Blue and now belong to the Hiper-Explosive club. It's been fine apart from the one failing on me. Decent voltages on all rails. I hope it can handle the extra load. I have managed to reduce my hard drive count by 3 in preparation so that should help.

 

[LSPIII]

what do you get in 3dmark05?

Not sure you were asking me but meh

I've done some tests on my setup pre-SLI so I can tell the difference when the SLI is put in place.

3D Mark '05 Stock: 7792
3D Mark '05 Overclocked GPU: 8830
3D Mark '06 Stock: 4318
3D Mark '06 Overclocked GPU: 4795

Not sure if those scores are actually any good for my type of setup but that's what they are anyway!

I'll let you know what I get when the second card arrives. Hopefully today

 

[LSPIII]

06 seems low though, especially as it's multi core threaded. What's your cpu clocked at?

Stock! Never really tried OCing the 4400X2 to be honest. I'm also in the process of making my machine as silent as possible, hence the lack of overclocking. I'll run the graphics cards at stock speed as well, just to prevent excess heat building up in the case. I do only have one graphics card in there at the moment and it may have something to do with XP x64 perhaps?

 

[LSPIII]

3D Mark '05 Stock: 7792
3D Mark '05 Overclocked GPU: 8830
3D Mark '06 Stock: 4318
3D Mark '06 Overclocked GPU: 4795

I'll let you know what I get when the second card arrives. Hopefully today

So the second 7800GTX is installed and running now. I have run 3D Mark again to some, well... bizarre scores:
3D Mark '05 Stock SLI: 11328
3D Mark '05 Overclocked GPU SLI: 11242
3D Mark '06 Stock SLI: 6776
3D Mark '06 Overclocked GPU SLI: Was heading the same way as '05 overclocked, only I noticed a frame rate drop qhwn compared with stock this time, so just aborted the test.

I'm relatively happy about the stock result. I should be able to run FEAR at 1920x1200 now with everything on (was so close to having it run nicely before SLI), as well as Test Drive Unlimited, so that makes me happy.

What do you guys make of the scores?

 

[LSPIII]

holy moly i dont want to be captain predictable response, but you'd be better of selling both cards and getting an 8800gts/gtx. my stock score is a good 4k higher in '06 and 6k higher in '05

I got the second card for cheap, who was I to say no! The 7800s don't go for much any more on the second hand market, so if I was to sell them both I would still need to put more cash in to get an 8800GTS let alone a GTX! I just don't have the money for that right now. Having the second card has made a real difference though. Fear is playable with everything on full at 1920x1200, I get the occasional jerking, but not a lot fortunately, so I can live with it.

 

[LSPIII]

do 2 cards in SLI always get outpaced by a single card a year later?

Not sure about a year later, maybe close to 18 months. My two 7800GTXs will outpace a 7900GTX single setup, and that was the card that replaced mine originally. The 8800 series cards really are just a massive step up though, unusually so I'd have said. That said though, Moore's Law states a doubling of power every two years so I guess about 18 months is about right.

 

[LSPIII]

the 7900 was just a refresh though, if you look at each new generation of cards it holds true. the x1800 > x850 crossfire / 6800ultra sli. 8800gtx > x1950 crossfire / 7900gtx sli.

True enough. But wouldn't you say that new generations come out once every two years roughly?

Edit: Probably more like 18 months having a look at it.