To SLI or not to SLI??

[cookiedude]

Hi all

I am looking at building a new rig and I'm thinking of taking advantage of SLI but haven't used it before so need some advice.

Basically I need to know if I will see similar performance from 2 8600gt cards compared with 1 8800gts card? The price difference is around £20, with the latter being more expensive. Would it be worth paying the extra for the 8800 and forgetting about SLI for now?

The motherboard I'm looking at would be something like the Asus P5N-E SLI, but this seems to run SLI at 8x rather than 16x?? Can anybody recommend a mobo that will do full 16x SLI?

Thanks in advance

 

[rebelyell]

Hey Cookiedude, I had the same concern when I built my newest system. I'm so glad I went with SLI. I'm able to set all the video options in games to their max settings and the effect is phenomenal. Not to mention the eye candy in games, my 3DMark06 score is just over 15,600 marks! If you haven't decided yet on a motherboard for your SLI rig, I can tell you from experience that the EVGA nForce 680i SLI motherboard is HOT! I'm using it with an Intel X6800 Core 2 Extreme proc and it's OC'd to 3.723 GHz from its stock speed of 2.93 GHz, ...and that's on AIR! My video cards are two EVGA nVidia GeForce 8800 GTX Supercloked with 768MB of graphic memory EACH. When it comes to SLI and bleeding edge graphics, I don't think you'll regret going for the gold and dropping a few extra bucks for an additional card. Let us know what you decide...

 

[LinkedKube]

Umm, to the comment above, your cpu is in no way bottlenecking your g80 cards. Obviously he's trying to use 8600 cards so he's on at least a semi budget. I'm not running sli right now, my advise to you is to buy an sli board and get the second card later. The board I'm using has sli x16 instead of the x8 on many boards. I think you should get a 8800 gts if possible then sli a little laster, two g80 gts in sli will outperform the gtx in sli because of bottleneck issues. this has been discussed in this forum previously. There's not a sing processor that's out right now that will unleash the full potential of the g80 gtx cards.

 

[cookiedude]

Hi rebelyell,

Thanks for your reply. The system you have is way out of my budget unfortunately, is it the nForce 680i boards that run SLI at the full 2 x 16X? I have been looking at a 650i board and SLI runs at 2 x 8X. Do you think I will see as good, if not better, performance from 2 8600gt cards compared with a single 8800gts card? I like the idea of SLI but my budget is limited.

The overall spec will be something like this:

XFX 680i LT edition SLI
Intel Core 2 Duo E6420 (2.13Ghz) Socket 775 FSB1066 4MB Cache
4gig OCZ DDR2 800MHz Gold GX XTC
2 x 250gig Seagate HDD
2 x 8600GT or 1 x 8800GTS graphics card
Creative X-Fi sound card
Etc, Etc

Should come in around £800 - about $1600.

 

[cookiedude]

Obviously he's trying to use 8600 cards so he's on at least a semi budget. I'm not running sli right now, my advise to you is to buy an sli board and get the second card later. The board I'm using has sli x16 instead of the x8 on many boards. I think you should get a 8800 gts if possible then sli a little laster, two g80 gts in sli will outperform the gtx in sli because of bottleneck issues. this has been discussed in this forum previously. There's not a sing processor that's out right now that will unleash the full potential of the g80 gtx cards.

Thanks for your input supersmashbrada. The 8800gts is a little bit more money than I want to spend at the moment, but i want that kind of performance. This is why I'm considering the 8600GT cards in SLI as 2 of these come in a fair bit cheaper than 1 8800gts. However, if this is still not going to give me the kind of performance I'm after than I will go for the more expensive 8800gts.

 

[LinkedKube]

the 650 boards with x8 are ok. Not recommended though. The set up you have is good, or the one that you will have. The 8600gt in sli should be fine unless you're running a 27inch monitor or something.

 

[thebaronjocelin]

Not personally having tried SLi, I would have to guess that the performance gain from running two cards of that magnitude at the best of times is limited.

 

[cookiedude]

the 650 boards with x8 are ok. Not recommended though. The set up you have is good, or the one that you will have. The 8600gt in sli should be fine unless you're running a 27inch monitor or something.

I'm currently running a 19inch monitor but this may jump to a 37inch plasma at some point (if and when I upgrade my main TV, then my old one will move into my bedroom). Would this cause a major problem for the graphics card? If it will then I may just stick to a LCD monitor but upgrade to a 23 inch model!?

 

[cookiedude]

What kind of requirements should I look for in a PSU to run an SLI setup?

 

[thebaronjocelin]

For SLi, you'd want to have a more heavy power supply. If you're using the aforementioned 8600's, you'd want around 600-650W.

If it's a television, you'd have to be more careful about the resolution than the size. 1280x720 is the same no matter how big the screen you put it on. If you go 16:9 Aspect Ratio on the plasma (which being a plasma, you're bound to get), you're most likely going to encounter a 1336x720 (I may be wrong about the W spec, but it's around there), and you can run most anything smooth by reducing that to 1280x720. You'll hardly even lose any screen space.

EDIT: Well, you'll lose around two inches, but it's negligible.

 

[MetalX]

Yes, but if that 37" TV is 1080p capable... (unlikely, but you never know) then you will be in trouble with 8600s, because 1080p is the unpleasantly large resolution of 1920x1080, and lesser videocards struggle massively at such resolutions.

 

[thebaronjocelin]

Everything struggles massively, but I doubt he'd get 1080p. That's just overboard for a thirty-seven "incher".

Still, he wouldn't have to fill all 1080 horizontals with a fresh pixel. Most of those TV's have more-than-rudimentary downscaling, because there's hardly any programming out there that'll broadcast at that definition.

 

[cookiedude]

If it helps, I have a panasonic PX70. The screen resolution is a rather odd 1024x720 - I think its to do with some plasmas using a more elongated pixel shape!? If it ever moves into the bedroom it'll be to make way for a 1080p screen for my PS3 (not for quite a while yet though) so i'll never be playing PC games at such a high res!

RE PSU: Are there any specific connectors this will need to have to utilise SLI?