OK...SLI or Crossfire?...and...

shutterspeed

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OK guys...It seems I am not hearing much about SLI and more about Crossfire these days. I have a second generation SLI board with two fairly old (less than 2 years) 512MB GForce 7800GT cards in there. I have a guy at a local computer store tell me that SLI is vastly inferior to Crossfire...blah blah blah. He said the NVidia cards are actually better, but if you want the best...buy two ATI cards and crossfire them. He said that on a 1 on 1 basis, the NVid cards beat ATI, but that when they are chained together, the ATI cards work together better. He said it is like having a Kobe Brant on a team with nobody else to score, or having a team full of Steve Nash's and one Dirk Nowitzki.

So I thought I would ask all the guys who would know.

He also said that you are better off buying the big card, than the one-step down model and getting two of them. He said that using two cards does not double your graphics power, and that it actually only increases about 30%. Is this true? If so, then why?

For some reason, the dude just didnt seem convincing to me. So I thought I would ask you all if he was full of RedBull or something.

He said the Crossfire cards are more like increasing 60% when you put them together.

So someone help me sort this out because I am due for a new bones kit.

I am the guy who usually buys one or two steps down from the top dog on hardware because I find the performance is usually pretty close for a fraction of the money.

So if anyone has any advice, maybe you might want to throw some my way on the new system too. I am not a big gamer but I do like driving sims which are pretty intensive on the machine. I am a pro photographer, and I am starting to shoot on medium format digital, which has files as big 400MB. I will probably drop in an SSD for photoshop reasons too. I am still sticking with XP for now, but want a system that will balze on windows7 when it is released, and thinking about the 64 bit version.

I am trying to stay under 600 on the board, RAM and CPU. Havent decided on the cards yet, but budget is always an issue of course.

Thanks guys...
 

DiscoDuck

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Unless you have a 30 inch monitor one top of the line ati or nvidia ought to suffice for most games up to 1080p resolution. SLI and cossfire sound fun but Im too practical to increase the likelihood of game crashes for my vanity sake and bragging rights.
 

shutterspeed

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My method has been to get two cards that are much less money than the top card. Thereby, in my theory getting more bang for the buck. Never had a crash with SLI so far.

Also, you didn't really answer the main question...which one SLI or Crossfire, and was this guy speaking the gospel?
 

invisik

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Sli and Cf scaling varies from game to game. All gpus scale differently just use google and see how he cards perform on the games you play. 2 gpus are pretty stable these days so i wouldnt worry.
 

shutterspeed

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Nobody really seems to be answering the question...

And I said I am not a gamer. I am more concerned about Photoshop, which does use GPU now. I run a driving sim once in a while too, but I am not a gamer really. To me, my Photoshop is my game. How fast a 200MB image file loads and how fast a really intensive action or plug-in runs, is what really gets me excited.
 

clutchc

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I can't answer your question about SLI vs Crossfire, because I have only ever used SLI. But as far as your query about one fast card compared to two slower cards in SLI... maybe this link will help you decide: http://www.xbitlabs.com/articles/video/display/gf-gts250-sli.html
 


A $600 budget gets you an i7-920, 6gb of ram, and a X58 motherboard. It doesn't get any better than that. You might want to look at 12gb, since I understand that photoshop responds well to ram.

Current versions of photoshop can use a vga card, and I think you can get a list of supported cards. I think the GTX260-216 is on the list, and it is a good value upper end vga card.
The problem with sli/crossfire is that it needs driver support particular to the game to be able to use the second card well. I do not know if photoshop is included.
Without such optimization, scaling might well be 1.3x.

For fast sequential hard drive processing, there are several options.

SSD's are very good at reading, but they are pricey if you are looking at capacities over 100gb. Writing speeds may be a problem. This type device is maturing very rapidly, and you might do well to wait and see what comes out in the next year or so.

In the mean time, raid-0 using several hard drives might be your best option. Look into a raid card with it's own onboard processor for best performance.
 

shutterspeed

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Well, I was trying to get a quicker simple answer than reading 18 pages of stuff. I skipped to the last page, and it seems the store clerk was partly correct.

NVid or ATI, not a lot of difference. Both great cards. So if the Crossfire board is less money, and the card is too, then Crossfire is going to be my best bet.

I am imagining that on the lower end of the vid card spectrum though, because the price differences between cards of condsiderable performance differences are close, that it would not be better to get two of the cheaper card instead of the bigger one.

For instance, you can pickup a 9800 GTX card for about 70 bucks right now. Are two of those going to be better than getting the GTC 260 for 180 bucks? It seems like it would be pretty close (or even better), and you are saving 40 bucks.

I also do not see any comparison like this on the Crossfire cards. Is there efficiency higher than the Nvid cards when chained together? It looks like Nvid cards are about 65% on average. Is the ATI stuff higher or about the same?

So in the end too...any kit recomendations anyone?
 

shutterspeed

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Has anyone seen any good articles on specifically built photoshop machines? I would think there would be some out there, but I havent had much luck with anything that seemed more than general. Oddly, I would think that Adobe would be smart enough to offer a "license" for an Adobe Optimized Design. But then again, they are really crappy on the "details"

As for SSD, I was going to use one supplemental to my main HDD setup (keeping the old ones of course) and use it as a scratch drive. I heard that its not the drive, its the system architecture that limits the speed of the SSD...but that's another thread I suppose.

I figured it would be almost as good as putting in 250 GB RAM. If I get that, and a kickin vid card setup, I might not need the girlfriend anymore.



 
In general, do not use multiple cards when a single better card will do the job.
At any given price point, you will get fair value for your money from either ati or nvidia. It is a very competitive marketplace.

Multiple cards willl require stronger and more expensive psu's, more expensive motherboards, and better case cooling.
The results will not be 2x the power of a single card. If the application has been optimized in the vga driver, it might get close to 2x, if it has not, then it might be<1x. Most results will be somewhere in the middle.

Only benchmarks of your application or game can tell. Don't extrapolate your performance from gaming benchmarks. You should be able to find some benchmarks on the internet.
 
A ssd will be a poor performer as a scratch drive.
The strength of a ssd is minimal access time and good random read times.
MLC ssd drives(the cheaper ones) suffer from throughput problems when writing.
Also, there is a limited lifetime number of writes that a ssd can do; not good for a scratch drive with lots of writes.

A conventional hard drive like the velociraptor will have much better throughput.

Here is one benchmark I found that might be meaningful to you:
http://www.driverheaven.net/photoshop.php