7900GT SLI vs 7900gtx?

Bogus69

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Hi,

I am in the process of deciding between 2x 7900GT (256MB) in SLI or 1x7900GTX 512MB.

I was wondering if there are any things to consider other than performance like heat and power comsuption or driver stability with SLI etc.

IO have seen some benchmarks that make the GT in SLI look attractive and as the cost is very similar between the 2 options....

Also, resale value? Will I get more for 2 GTs than 1 GTX?

Anyone had bad experiences running an SLI setup?
 

Bogus69

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I'm pretty sure that you will want the dual 7900 GTs. It will cost $50-80 more, but your fps will rarely, if ever, dip low.
SLI isn't worth the money, so I'll rather have a single, better card, than two good cards.

Although 7900GT is one of the better cards available, I would prefer more powerful 7900GTX or X1900XT.

BTW, you do get performance losses in SLI. And on top, SLI mobo and PSU that will run dual cards.


What performance loss are you refering to with SLI?
The Mobo and PSU that I will be getting supports SLI anyway so I won't be saving dollars there by not getting 2x GTs

When you say that SLI is not worth the money, how much extra are you thinking it will be?
In my case the extra is about $100 USD for what looks like a 25% increase in high res (with full AA) performance.

Does that change your opinion at all, or is there some extra info you know you can pass on?

Cheers.
 

Lan

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Correct me if I'm wrong prozac.

I believe that he is referring to the best bang for the buck issue. In most if not all cases 2 7900GT's will out perform a single 7900GTX (not sure about an X1900XT).

However, you are paying for 2 7900GT's for only a little better performance than a single 7900GTX. As you can see from my sig I own 2 7900GT's and love them. But I had the money to burn anyway.

The performance loss he is referring to is that using SLI you only gain a 30% performance increase at most, but you have to pay twice the price.

Personally the bottom line as I see it is that if you have the money and don't care about the bang/buck ratio, then go for it. If you want the best buy you can get while still having decent performance, do as prozac said and get a 7900GTX or X1900XT. Hope this helps. :D

EDIT: After reading my own post I want to add to the performance loss issue. It largely depends on the game but there are dips in performance during heavily rendered scenes, and while I haven't played Oblivion on my computer yet, I've heard that ALL cards take a major performance hit rendering that game.
 

MrCommunistGen

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He may also have been talking about how some games that are already CPU limited will take a performance hit in SLI because SLI requires some processor overhead.

-mcg
 

shabodah

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It's not that it is stupid, it's a great idea, actually. However, there is a big case of diminishing returns with SLI. It's kinda like with sports cars. Dollar for dollar, they seem to go up at a linear rate until you hit the 400 horsepower mark, then you start paying 100% more for 25% more performance, and it gets worse from there, case in point- 2006 Z06 vs. Ford GT.
 

toe49

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if you play at large resolutions, i.e. 1600x1200 or larger, thats really what sli would be better for, because thats the only thing that can really slow it down. However, if youre running anything below 1600x1200, a single card solution would be better, since you wont notice much of a performance difference at all between 1 or 2 cards. in my opinion, get the x1800xt 512mb from newegg, its ~$330 and performs best in lower resolutions, and not to mention ati cards have much better image quality
 

GFKiraR

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well aslo you have to ask yourself how many monitors are you gonna run, and if they can support sutch high resolutions. anyways if your not gonna run at least 2 monitors in a SLI setup then its pretty useless to have two cards, otherwise your better off getting the 7900GTX or ATI X1900XTX(not the XT!) also yes ATI has better Image quality but Nvidia has mutch higher Frame rates, so it comes to what you want.
 

Bogus69

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When you say that SLI is not worth the money, how much extra are you thinking it will be?
In my case the extra is about $100 USD for what looks like a 25% increase in high res (with full AA) performance.
SLI doesn't double performance, so why pay double for it?



By the same virtue, why buy a 7900GTX?


Here's the thing....
1x 7900GT = $485
2x 7900GT = $970
1x 7900GTX =$835

Looking at the tests on THG it looks like 2GTs are about 25-30% faster at high res. That to me sounds like good bang for buck if using high resolutions.

I started off thinking I would buy a single GTX, then when I could only find mobos with SLI which I liked, I thought "What about 2xGTs!"
My compasison was always between 1xGTX and 2xGTs.
Never 1xGT vs 2xGT. So the price is not double ;)

What I am interested in is the down sides that some of you have put forward.
ie.
Possible CPU use
SLI bugs or incompatabilities
Image quality degradation etc, etc.

I will be running a single 20" widescreen LCD @ 1680x1050 which lead me to think the high res benchmarks would apply to me.


Comments??
 

smedlin

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Umm..where did those prices come from?

Newegg has the GTX starting at $509. Even back when they where hard to find, I got two BFG 7900GTX for a total off $1,100
 

shabodah

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Yeah, where DID he get those prices from. 7900GT range from 300-360 where I've looked. And heck, the EVGA one at 350 is running an overclock approaching GTX speeds.
 

Bogus69

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Sorry. Thats Australian dollars. :)

So is there any down side to having SLI?
Do the drivers work well, no problems?
Does the picture look as good as if it were a single card, no line between top and bottom, or no sync issues?
 

smedlin

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I have no problems. If you can affored it, then get sli. The extra frames are nice. I run fear at max resolution (19 inch moniter) and maxium settings with an average fps of 107.
 

Lan

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Sorry. Thats Australian dollars. :)

So is there any down side to having SLI?
Do the drivers work well, no problems?
Does the picture look as good as if it were a single card, no line between top and bottom, or no sync issues?


The only downside to SLI that I can see is the price you pay for buying two cards instead of only one. I haven't had or found any issues at all running SLI in my machine (in my sig). Sure, there will always be performance dips on any setup, but that largely depends on what program you are running, and not the hardware itself.


It looks like your mind is made up. If you got the money, then go for it and enjoy your SLI. I know I'm enjoying mine. :D