SLI 8800GTS 640mb

[Epilon]

I ordered my 680i and 2 8800gts's to run in SLI. I was really expecting that this would be a pretty good gaming setup, as I have been told. I was then looking on the Techreport.com benchmark pages, and saw that single cards outdid the 8800GTS in SLI in a lot of games. I was a little confused, and frustrated as in that I spent 200 dollars more to go SLI then buying one GTX. Can someone explain this to me as to why they are recieving lower benchmarks? Patch problems? Will it improve?
I havent put my computer together yet, as UPS keeps losing my package, but Im looking forward to seeing how it runs.
Thanks

[drotto25]

Sli does not scale 100%!!! If you look at a wide range of benchmarks in games you will see (depending on how well a game can handle SLI) performance increases will generally range from 20 to 50%. There is the rare case that you can get higher than that and theoretically can go to 100%, but have only seen that in synthetics. In general, the 8800 utlra or an oced 8800gtx will outperform 2 8800gts in many situations. I have read a few times that if you have the money the one card solution is generally prefered do to less system complexity, driver issues, program comflict issue. If you have maxed out possible speed with one card, then if you still have cash get a 2nd card.

Add to that that at common resolutions (ie upto 1600 x 1200) very few games exist that even stress one high end card. Now if you move up in resolution and larger screen sizes, you will see benifits to SLI as the one card begins to struggle.

I am not sure exaclty why this occurs but contributing factors may include

1. bandwidth availible on your pci-e slots, you now have 2 cards competing for that space
2. limitation on cards comunicating with one another via sli bridge, the cards must now compute and coordinate the division of labor.
3. CPU limited applications
4. Drivers especially in vista where sli support is just plain broken.

If I am way off base on this let me know, and please if you know the true technical reasons please explain.

[Thund3rball]

I don't know all the technical details but ya... one high end card is better than 2 SLI'd lesser cards. If only you came to OCF before you bought those 2 GTS cards. However... you may be able to return them and get a GTX IDK?

:(

[xilix]

Like Thunder said, I'm not sure if you can return those two cards and get a single Ultra or GTX, but if you can, do it, and take the extra $200 and put that towards a water cooler or really good air cooling for it, and then OC. If you can't return them don't worry, you'll still have a great system. One thing you could do if you can't return them, is take a small loss, and sell them NIB for slightly cheaper than you got them, and then get a GTX or Ultra with that money.

Either way I'm sure you'll be happy with your setup. New rigs are always fun and I'm sure you'll be able to run Crysis with most of the candy on.

[ChinStrap]

I don’t know why there isn’t a lot of love for SLi around here, but I have 8800gts(s) in SLi and love it. When I picked up my first GTS I didn’t have the money on hand for a GTX and the ultra was not even out yet – then like 4 months later I had some extra coin, so I went SLi and never have looked back.

In general, the 8800 ultra or an oced 8800gtx will outperform 2 8800gts in many situations.

This is just untrue, I air cool my cards and can run overclocked up to 651/1020 – no single overclocked GTX or Ultra can beat any of my scores on AIR cooling. – Just check the benchmark section if you don't like how that sounds :)

In gaming a like, many of my clan mates run single overclocked 8800GTX’s and don’t get near the FPS I do with everything turned to max in COD2.

1. Bandwidth available on your pci-e slots, you now have 2 cards competing for that space
Not a problem, the 680i has duel 16x PCIe slots when run in SLi, and considering a single GTX can’t saturate a 16x slot alone, this is not a problem.


Clock that core 2 up to about 3.5GHz and just enjoy superior frame rates

[drotto25]

I was half asking questions, not nessesarily stating fact. I do not really know why SLI does not fully scale, and was thowing some ideas up. I understand that one 8800 does not fill the pci-e bandwidth, but two may thus why you do not get a 100% scale.

I have no problem with SLI and it can be great in certian situations for sure, but most games can run at max settings at good resolutions without sli especially the gtx and ultra. I actually may go to SLI in the future thus why I stuck with a 680i mb. Most of my concerns with SLI come form a cost benifit analysis. It is alot of extra cash for at best a 50% increase in real world applications. A 8800gts 640 mb runs around 350 so 700ish spent on video cards for sli. A gtx is 520ish and I got my MSI 8800 ultra oced for 610. So I think many people question SLI from a cost performace perspective. But if I had all the cash in the world SLI here I come.

I conceed that I did a little more research and the gts sli combo does consistanly equal or beat a 8800gtx and ultra single. In fact the SLI gts setup wins on average by 5% to 7% roughly. This is of course without taking ocing the cards into account. So an oc as nice as yours, I sure see that beating any stock single card setup.

[Epilon]

Sli does not scale 100%!!! If you look at a wide range of benchmarks in games you will see (depending on how well a game can handle SLI) performance increases will generally range from 20 to 50%.


Thanks for the info, but I know that SLI does not scale 100%.
But chin strap, thanks for some reassurance. I was wondering if they weren't doing so hot due to poor driver support? Could the GTS's be optimized in the future to beat the competition?

[ChinStrap]

you always hope... you know!?

with each driver release it gets better and better, rivatuner is also your best friend :)

[Gripp]

sorry, not to hi-jack your thread or anything but..
i'm still struggling with this same issue atm... the 680i SLI bit seems great
but apparently one 8800GTS OC'd on a P35 is just as good? but, have to worry about water cooling...
but on the flip side to that the P35 is possibly(?) more suitable for future upgrades...

either way, SLI with air or P35 with water - its about the same cost and performance from what i'm coming up with...

so i wouldn't worry about it, what you have is fine
unless you;re dead set on making a super-cool water system...

[Epilon]

sorry, not to hi-jack your thread or anything but..
i'm still struggling with this same issue atm... the 680i SLI bit seems great
but apparently one 8800GTS OC'd on a P35 is just as good? but, have to worry about water cooling...
but on the flip side to that the P35 is possibly(?) more suitable for future upgrades...

either way, SLI with air or P35 with water - its about the same cost and performance from what i'm coming up with...

so i wouldn't worry about it, what you have is fine
unless you;re dead set on making a super-cool water system...

Naa this is actually my first build, and I was reccomended, Since Im a gamer, to go SLI 8800 GTS and overclock. Im on air and having a crazy water cooling system isn't my thing right now. I really just want to play DX10 crysis in a state where it looks pretty good. Not Max everything mind you, but something that people will go, Holy S*** at.

[ChinStrap]

sorry, not to hi-jack your thread or anything but..
i'm still struggling with this same issue atm... the 680i SLI bit seems great
but apparently one 8800GTS OC'd on a P35 is just as good? but, have to worry about water cooling...
but on the flip side to that the P35 is possibly(?) more suitable for future upgrades...

either way, SLI with air or P35 with water - its about the same cost and performance from what i'm coming up with...

so i wouldn't worry about it, what you have is fine
unless you;re dead set on making a super-cool water system...

i'd go SLi with air, if thats what your asking. again, higher FPS.

[MadMan007]

Could be old driver revisions in the write-up that you read. I'd like to see more tech sites do 'new driver' revisits on hardware they've already reviewed. Some games aren't as good with SLI as others but that was already mentioned.

[satandole666]

I've never used SLi before but from what I understand the memory on the two cards is not additive. So...

If you have 2 640mb GTSes you have 640mb of vram.

If you have 1 ultra or GTX you have 768mb.

I'd imagine there are some situations where that plays a larger factor and the scaling isn't as great. In more GPU bound situations you would hopefully see higher scaling.

Just a though as to why you aren't seeing the scaling you want.