Why bother with SLI/Crossfire?

mattdp

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Can someone explain to me the attraction of SLI/crossfire?

Looking around at some benchmarks it seems to me as though doubling up the graphics cards gives an increase in performance of somewhere between 0-30%. One article I read suggested that in some games, using sli might even lead to a small performance decrease over a single card. To gain this performance boost, you're obviuosly having to buy two cards and so pay double the price.

So lets say I've got a 7600GT (which I have). It cost me £150. By spending another £150 I can get another card and get me a 30% maximum performance boost. But wait ... that's £300, and for that money I can buy a cheap X1900XT which is going to give me somewhere between 100% and 200% performance boost, depending on the game. So if I've got a spare £300 to spend, guess which I'm going to go for?

So unless you're a millionaire buying a supersytem with twin X1900XT cards, why ever bother doubling up? It seems you'll get much better performance boosts for your money by just buying a more expensive card.
 

Flakes

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which is why we tell ppl to just sli if there building a top of the range pc and have the money.

forinstance if someone wanted two 7900GTX and they had the money i would say go for it. but if they wanted two 7800gt in sli i would say buy one 7900GTX instead.
 

Primitivus

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There is another reason why someone would bother with SLI actually... If you bought a 7800GT last year and now you find yourself with around $150 to spend on your rig but NOT with $300 and you don't want to wait until you save enough for a new gen card then obviously you can go the SLI route. Duh!
 

Kodiak666

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There is another reason why someone would bother with SLI actually... If you bought a 7800GT last year and now you find yourself with around $150 to spend on your rig but NOT with $300 and you don't want to wait until you save enough for a new gen card then obviously you can go the SLI route. Duh!

Agreed!
 

cleeve

Illustrious
You've basically restated the prevailing opinion on this forum.

SLI/Xfire are viable only if you have money to burn. It even makes for a crappy upgrade path because video card technology advances so quickly.

Having said that, if you can afford two X1900's or 7900's, want the best money can buy, and play at very high resolutions - more power to you. There's nothing wrong with the hardware, but alot of people buy it for the wrong reasons.

I wonder how many poor schlubs out there spent the extra $$$ for an SLI motherboard when they bought a 6800 Ultra. Is ti worth it for them to buy a second 6800 Ultra now? Of course not. Wasted money.
 

ProdigyMS

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which is why we tell ppl to just sli if there building a top of the range pc and have the money.

forinstance if someone wanted two 7900GTX and they had the money i would say go for it. but if they wanted two 7800gt in sli i would say buy one 7900GTX instead.

I definately agree with this guy. The only real reason I would blow $1200 on dual high end video cards is if I had $1million, and I needed it for high resolutions. But I never game at high resolutions, 1024x768 is just fine with me. The new generations of video cards are coming so fast its worthless. When the 7800GTXs were released, and people went SLI with those, they dropped around $800 on videocards? A few months later, 7900GTXs are out, and a single 7900GTX would beat dual 7800GTXs, and it's about $200 cheaper. Absolutely worthless if you're looking for a good performance gain, it should be double performance.
 

clue69less

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I wonder how many poor schlubs out there spent the extra $$$ for an SLI motherboard when they bought a 6800 Ultra. Is ti worth it for them to buy a second 6800 Ultra now? Of course not. Wasted money.

I've been wondering what the life expectancy of PCI-E and SLI/XF is? AMD has a memory controller on the CPU. Is there a possibility of an improved graphics-specific interface happening in the forseeable future? Seems like a logical progression.
 

cleeve

Illustrious
PCI-e will be here a long while. Changes in busses are few and far between because all card makers have to comply, and it's rare that performance suffers to the point where it's a necessary upgrade.
 

clue69less

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PCI-e will be here a long while. Changes in busses are few and far between because all card makers have to comply, and it's rare that performance suffers to the point where it's a necessary upgrade.

That's part of the point I'm making. If mobo designers designate a buss as being graphics-specific, then that lack of universality makes it easier to justify updates. With the pace of development in graphics hardware being as active as it is, it just seems logical to give it more priority in the I/O heirarchy.
 

Heyyou27

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SLI and Crossfire are the worst possible upgrade paths.
After seeing the transition to the 7900s, that is definitely true.

Although people are always saying "SLI AND CROSSFIRE DON'T GIVE MORE THAN A 30% PERFORMANCE INCREASE" This is not usually true, but we also have to consider other parts of the PC that can increase and decrease performance. Why is it always the complaint "200% THE PRICE FOR 30% PERFORMANCE INCREASE"? I forgot the CPU and RAM don't impact performance at all.

I am not saying SLI and Crossfire are always a good solution, but most people on the forum are skeptical of dual card setups; just because you don't want to buy it, doesn't mean you have to try and discourage me from doing so.
 

FITCamaro

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I'm far from rich but I'm considering X1900 Crossfire. I'm upgrading my computer and would like to play the newest games with all the eye candy on. Games like Oblivion can really slow down a fast system even at 1280x1024 with the settings on max so I don't want that to happen. Plus ATI is planning physics in its graphics cards so I'm looking forward to that. My upgrade cycle is about 2 years so spend almost top dollar for the good stuff now so it'll last.

Then again I'll be getting just one X1900XT to start so I might wait for the new cards to come out, get one of those and then use my X1900XT as a physics card if ATIs drivers allow for it.
 

bweir

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It's obviously targeted at those who can afford the P4 EE's or the AMD FX series, and who don't mind throwing money into the wind.
 

cleeve

Illustrious
In this case, graphics going PCIe from AGP 8x was just a natural progression, it wasn't a graphics-driven decision.

Form what I understand, PCIe was created because PCI is so damn slow, for every card that isn't your graphics card. It wasn't targeted towards video specifically.

The video guys just jumped on the bandwagon since the new spec offered theoretical bandwidth improvements, even though the 8x AGP bus was far from saturated.

PCIe still shown no performance improvement over 8x AGP.
 

ikjadoon

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In this case, graphics going PCIe from AGP 8x was just a natural progression, it wasn't a graphics-driven decision.

Form what I understand, PCIe was created because PCI is so damn slow, for every card that isn't your graphics card. It wasn't targeted towards video specifically.

The video guys just jumped on the bandwagon since the new spec offered theoretical bandwidth improvements, even though the 8x AGP bus was far from saturated.

PCIe still shown no performance improvement over 8x AGP.

Not trying to start another f'ing PCI-e/AGP war, but I totally agree with you...It was supposed to faze out PCI, not AGP. PCI is getting slow....

~Ibrahim~
 

Primitivus

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That wasn't the point bweir was making. He was just commenting on the target group. Because you can also have An Athlon 64 FX-60 running with a Radeon X300... (theoreticaly) but would anyone do that? OK I know it's much more likely for people with SLI/Crossfire to try and "save" some money by opting for a CPU that's not ultra high-end but I don't expect anyone with two 7900GTX's to be running a P4 511, do you?
 

Primitivus

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Then again I'll be getting just one X1900XT to start so I might wait for the new cards to come out, get one of those and then use my X1900XT as a physics card if ATIs drivers allow for it.

Don't hold your breath. I think the 1900XT is the best bang for the buck right now, as far as high-end graphics are concerned, but if I were you I wouldn't wait too long to Crossfire it and I definitely wouldn't expect such specialisation from the drivers