Crossfire vs SLI

[AdamK47]

This will be the deciding factor between me getting two new Ati cards or waiting a few months for two new nVidia cards. I'm mostly happy with the SLI from my two GTX 280s, but I don't have any first hand experience with Crossfire. How is the game support with Crossfire? When a new game comes out does it support Crossfire in some form right out of the box? With SLI it relies on game profiles and for the most part works with 90% of the games available. If there isn't a profile you can manually add one. Is this the same with Crossfire, or is it managed differently?

 

[Hauk]

Hopefully you'll get responses and not a smack down.

IMO, ATI scaling has improved drastically, while nV scaling goes from good to excellent. I've used nV multi-gpu since 8800GTX and ATI with 4870's. I play every game for a bit with the nV SLI meter turned on so I can check scaling and as you said, seems excellent the majority of the time. ATI, no meter yet. Benchmark gains with titles like FC2 and Crysis do show 48xx scaling has improved however.

Next gen is bittersweet when you have something as nice as a GTX 280 SLI rig isn't it? Such great perfomance, great scaling. But time marches on. If you're not too concerned about resale value continuing to plumment on your 280's, you're solid until all the cards are on the table.

Regarding "out of the box" scaling, I think both camps are even, playing catch-up as big titles are released. I wish there were a review site that focuses on multi-gpu but there isn't. Best thing is to find one that includes multi and look at the charts, 1x vs. multi of the same gpu. Guru3d, FiringSquad, etc.

 

[aka1nas]

From what I've seen in reviews, both solutions work pretty well in the majority of games now. Crossfire sometimes has better scaling in some reviews, but also had more games that didn't function properly (i.e. no performance increase). My personal experience is all with SLI rigs as well, so I unfortunately don't have any direct observations on Crossfire that I can provide.

 

[Udgnim]

I have not ever run a CF or SLI set up so all my info is hearsay.

I think Nvidia generally provides better support for SLI than ATI for crossfire for new games. the support difference is usually most noticeable when a Nvidia "the way it was meant to be played" title is released since Nvidia has an opportunity to work with the developers whereas ATI does not.

you usually have to wait for a new driver release (which is month to month) from ATI if CF does not work out of the box for a game.

 

[wrangler]

Hands down nVidia provides better, faster support for their multi-gpu solutions. Not saying that their multi-gpu solutions are faster performers, just that the support for profiles and drivers is faster and better. Crossfire when it is properly implemented is a wonderful thing.

With Crossfire, you will not have a profile enabling multi-gpu support on a new game release until AMD decides to release a profile and in their case that can be significantly later than the game is released and they provide no option in their control panel to make your own. I've heard that there are ways to force at least AFR but it's not like it is a checkbox in the control panel. I've also heard that there is a 3rd party program that will allow you to make your own profiles but again, ymmv. Whether that 3rd party program works could depend on your OS or on whether your running 32 or 64 bit version of said OS. I'm not interested in screwing with anything like that but you may well be. I just want it to work.

WIth nVidia, they probably subsidized the game and there will be a profile before the game is even released. If not, you can go in and do your own selecting from multiple versions of AFR or SFR and decide what works best for you.

I currently own a 4890 and love it. Before that I had a 260. Before that I had 4870-512 Crossfire (hated waiting for profiles and sold them). Before that was a long string of nVidia cards including several SLI setups most recently 8800GTS-512 SLI. Somewhere in there was an ATI 9600XT. I like to try lots of video cards.

If you must go multi-gpu, SLI is still the king. imho

 

[AdamK47]

That's kinda sad to hear about Ati's method. I do like to create my own profile and change the way multi card rendering works for a game.

 

[AdamK47]

What's the verdict with Crossfire and the 5870? Has crossfire improved? Is it tweakable?

 

[Hauk]

"Times faster than single card" are key charts in this review:

http://benchmarkextreme.com/Articles/HD 5870 TriFire/P4.html

Depending on resolution, you'll see some low numbers, like 1.3x faster compared to 1.7x with GTX 285 SLI. nV's drivers are much more mature of course.

You'll see 1.6x or better with 2560 x 1600 so that makes me wonder, is it immature drivers, or inability to tax that 2nd gpu with lower resolutions.

A single 5870 neatly handles today's games at any resolution. I'm all about wasting money on multi-gpu configs, but I wanna see them scaling though!

 

[Grooveriding]

My 5870 CF setup is insanely fast, it maxes every game out there no problem. That said, in the game we like to bench most (Crysis) the scaling is not that insane, it scales, but the 5870s don't scale as well as the 285s do.

Other than Crysis though, 5870 crossfire is crazy fast, just look at any of the benchmarks out there. There are plenty, I would check the guru3d, techreport and maybe toms reviews of 5870 crossfire. Benches will speak for themselves.

 

[JAG87]

SLI is better for 1 reason. nHancer.

Otherwise they are the same, which means they are as good as Ati and Nvidia allow it to be. No customization means no chance of user created solutions when bugs appear. And trust me, bugs DO appear and sometimes remain there forever.

 

[dguy6789]

Nvidia's method has profile support for specific games and also a general method that works for any game. The general method usually works pretty well but not always consistently well across all of the games but it's better than nothing at all.

ATI's method does not have a general method of supporting games, so it only works on games that ATI specifically writes support for. ATI updates them once a month so you won't go long without support for new games. They've been good about supporting the latest and most popular games for quite a while.

In terms of general game support, Nvidia has the upper hand since SLI will usually work to some degree on nearly any game. But for game specific support, ATI adds games to thier profile list more often than Nvidia does.

 

[yh125d]

General consensus is that they are pretty much the same. Pick whichever is better as a single card for price/perf then buy two

 

[BFG10K]

If I had to pick one, I'd go with nVidia.

Custom open profiles (nVidia) versus fixed closed profiles (ATi).

 

[Borealis7]

The real question on everyone's mind is how good is HYDRA going to be.

*if* it delivers, XF and SLI will become obsolete, plus it wont really matter what cards you get unless NV puts roadblocks on their drivers.

 

[AdamK47]

If I had to pick one, I'd go with nVidia.

Custom open profiles (nVidia) versus fixed closed profiles (ATi).

Yeah, that's what my feeling is. I like to at least be able to control how the multi card rendering is being applied if there is no profile available or the default profile isn't optimal. I've had to do that dozens of times with my nVidia cards.