MultiGPU Update: Two-GPU Options in Depth
by Derek Wilson on February 23, 2009 7:30 AM EST- Posted in
- GPUs
Final Words
There is quite a bit of data here today, and it can be a little bit daunting to sort through. In every test but one, GeForce GTX 285 SLI leads the way in performance. Often the GTX 280 SLI pops up next. That's surprising considering the fact that AMD doesn't have as heavy hitting a single GPU part. And it also doesn't take into account the fact that these two solutions often come in very low in the "value" lineup and not that much higher in performance than something like the Radeon HD 4870 multiGPU options or even the GeForce GTX 295.
The cheaper Radeon HD 4870 X2 often does better than the GTX 295, and often multiGPU AMD options have better value than the highest end single GPU options from NVIDIA. But the real stand out has to be the Sapphire Radeon HD 4850 X2 2GB. This unique card really shined and held it's own all the way up to 2560x1600. While a 1GB 4850 might not make much sense (the extra RAM only really helps at resolutions where the 4850 can't keep up in terms of processing power), the 1GB of RAM per GPU on the 4850 X2 2GB really helps make this single card multiGPU option high end.
The Sapphire 4850 X2 costs less than a single NVIDIA GTX 280 or 285, and performs better than these as well. While the Radeon HD 4870 X2 is viable as high end single card multiGPU option, it competes at a price point beyond NVIDIA's high end. the 4850 X2 really puts pressure on anything that costs between $300 and $400 from the competition. It's very surprising to us that AMD hasn't pushed this configuration and that Sapphire are the only manufacturer to have put one of these out there.
In general, more than one GPU isn't that necessary for 1920x1200 with the highest quality settings, and the Radeon 4870 1GB or an overclocked GeForce GTX 260 core 216 are good options there. Slower single cards are fine for the high quality at 1680x1050 and multiGPU options are basically wasted at this resolution and lower except in Crysis. As we've seen in past tests, only those with 30" monitors will really benefit from multiple GPUs in their system for now. Of course, there are value-add technologies like PhysX and hopefully sooner rather than later OpenCL will attract more developers to GPU computing. But when were talking multiple graphics cards for rendering it's really not worth it without the highest resolution around.
If you want to break it down, the only NVIDIA single GPU solutions we really recommend as an option are the GeForce GTX 260 variants and/or SLI which are on par with the Radeon 4870 512MB and 1GB depending on the games we chose to test. Really the decision comes down to which games you prefer to play and what features you want. Buying a single GPU solution for more than $300 doesn't make sense with the efficiency of the 4850 X2, and the prices on higher performance multiGPU solutions make them a tough sell really. The GTX 285 SLI is the performance leader, but the cost is just huge.
As we mentioned, this is the first of a series of articles that will explore multiGPU performance. The next article will tackle 3-way SLI and 3-way CrossFireX options. The goal is to extend this look into the 3-way realm, looking at scaling from 1 to 3 and from 2 to 3 cards in a system along side pure performance and value. While this will use much of the same data we've looked at today, the focus will be on 3-way and whether or not it has any real practical use.
While we've already seen 2 GPU performance data, we hope that this more in-depth look than usual helps to illustrate the playing field a bit better. AMD (with the help of Sapphire) really has succeeded at their goal of making single card high end options that compete well with NVIDIA's high end single cards. While the Radeon HD 4870 X2 does compete well with the GeForce GTX 295, the 4850 X2 2GB does a great job of offering higher performance than NVIDIA single GPU options and much more bang for your buck at a price point right below the GTX 280.
Our one caveat with AMD remains driver issues. We are happy with Catalyst 9.2 as it competes with the 8.12 hotfix in terms of stability and performance (and it offers more multiGPU support for recently released games). NVIDIA's GeForce GTX 260 core 216 offers good competition for AMD, and driver support issues don't do AMD any favors. Drivers are even more important when it comes to SLI and CrossFire. SLI enjoys much better support from NVIDIA than CrossFire does from AMD. Because of AMD's driver issues, we often have to wait when new games come out to enjoy proper CrossFire scaling with them. And when hotfixes come out it takes more than a month (usually more like two) to fully integrate changes into a WHQL driver. This is quite disappointing and is really the only strike against the Radeon HD 4850 X2 2GB which is in every other way terrific competition for NVIDIA's lineup.
Sometimes you don't get what you pay for, and with less than linear scaling we do see a reduced value from multiple card solutions. Sometimes getting playability at a higher resolution makes this reduced "value" worth it. Sometimes, CPU and system limits can also reduce value for more than one GPU. And sometimes, like in the case of the Sapphire 4850 X2 2GB, we see a single card that costs the same as two separate lower spec'd (in this case lower memory) parts and can therefore offer great scaling and incredible value.
Stay tuned to see how three cards changes the landscape.
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Nighttrojan - Wednesday, February 25, 2009 - link
Well, the problem is that I tried it at the same settings too, the 7600gt was still faster. The difference is so great that it takes about 15s for the 4870 to even process a change in settings while with the 7600 gt it's practically instant.mrmarks - Tuesday, February 24, 2009 - link
Is bolting two video cards together really necessary? I've played Call of Duty at max settings on my two year old midrange card and it ran beautifully. These cards seemed to be designed for games not of today or tomorrow, but rather for games that may never exist. Few store fronts sell pc games today, and many of the games produced today are not terribly graphics intensive. Also, most popular pc games are available on consoles, which are much more practical. I know this sounds negative but the truth is that the video card manufactures are just ignoring the current pc game market.SiliconDoc - Wednesday, March 18, 2009 - link
Geeze dude, there are hundreds of PC games out every year. I suppose the couch console has a wider selection, but it's not like we're dead space here. (hahah)I guess it's easier to sell to Santa for the little curtain climbers when even Daddy has a resistence problem. ( Believe me, it's a standing joke amongst friends).
Then we have the kiddies screwing up the computer issue - not a problem when the household heads do so... the console keeps the PC functional, so to speak.
But really, lots of game choices for the PC - the biggest retailer in the USA - you know whom - has loads of PC games. Ever heard of best buy - aww just forget it.
Just go whine somewhere else would ya ?
Elfear - Tuesday, February 24, 2009 - link
^ Go take a 2nd look at the 2560x1600 res graphs. In almost every case the single cards are struggling to keep their heads above water and in a few cases failing miserably. Ideally, minimum framerates would be >60fps in all of today's games for that buttery-smooth feel but we are far from that with even dual graphics cards.I agree with you that dual graphics cards are not needed by most gamers but to say that there is no need period is ignoring reality.
JPForums - Tuesday, February 24, 2009 - link
I'm confused about your opinion on AMD drivers. You made this comment in this article:"Because of AMD's driver issues, we often have to wait when new games come out to enjoy proper CrossFire scaling with them. And when hotfixes come out it takes more than a month (usually more like two) to fully integrate changes into a WHQL driver."
However, you've also made comments in multiple articles similar to this one from GPU Transcoding Throwdown: Elemental's Badaboom vs. AMD's Avivo Video Converter on December 15th, 2008:
"The train wreck that has been the last few months of Catalyst has happened before and it will happen again as long as AMD puts too many resources into pushing drivers out every month and not enough into making sure those drivers are of high enough quality."
So on the one hand it seems you are criticizing AMD for not releasing WHQL drivers soon enough. While on the other hand, you seem to want them to take more time with their drivers. Anandtech is not the kind of site to post contradicting opinions on a whim, so I have to assume that your opinion simply hasn't been stated clearly (or I just missed it).
I remember a comment from an article to the effect of nVidia has a good driver release model. It is interesting to note that nVidia's driver release schedule over the last 6+ months hasn't been all that different from AMD's schedule.
nVidia's driver release schedule:
182.06 February 18, 2009
181.22 January 22, 2009
181.20 January 8, 2009
180.48 November 19, 2008
178.24 October 15, 2008
178.13 September 25, 2008
177.41 June 26, 2008
177.35 June 17, 2008
182.05b February 10, 2009
181.22b January 16, 2009
While nVidia doesn't have a specific release data, they have on average put an update out nearly every month. Being a user of more nVidia hardware than AMD hardware I know that nVidia uses beta drivers in a similar fashion to how AMD uses hot fixes.
In my opinion, AMD needs to ditch the set release date. They should try to target updates about once a month, but release them only when they are ready. I do think their driver team is likely understaffed, but I a think nVidia's The Way it's Meant to be Played program plays a significant role in why nVidia can support certain games well at launch and AMD can't. Though, I can't say whether it's simply good nVidia developer relations or forced negligence towards AMD. I don't really have a problem with them releasing hotfixes, especially given that AMD has had issues supporting some games at launch, but if their driver team and/or developer relations were better, they wouldn't need them as often.
I would, like to hear more clearly stated opinions from Derek and Anand on this subject. Thanks.
SiliconDoc - Wednesday, March 18, 2009 - link
Here's a clearly stated opinion. ATI KEEPS ******* IT UP, while their competition does a good job.Patrick Wolf - Tuesday, February 24, 2009 - link
What's the word on overclocking these multi-gpu setups? I can only speak for the 9800 GX2 but it's a very good OCer. EVGA GX2's lowest end model is 600/1500/1000. The SSC edition is 675/?/1100. Same card, just factory overclocked.I was running the lowest end model @ a stable 715/1787/1050 Currently testing out 720/1800/1065 (w/ the GX2's cover removed) with good results.
mpk1980 - Tuesday, February 24, 2009 - link
i think the 2 gtx 260's in Sli are a good value right now...that setup comes in the top of the charts most of the time competing with the 280 and 285 sli setups and right now...can be had for less than 400 at newegg after rebate (380ish i believe) which is just as cheap at 1 gtx 285 and 120 cheaper than a 295.....i dont think you can go wrong with that right now....and i cant wait to see 3 of those badboys in tri sli :)gigahertz20 - Monday, February 23, 2009 - link
Very few people (like around 1%) that read this article play games at 2560x1600, because that resolution requires a CRT monitor or a super high end LCD monitor (not even sure where to get an LCD that goes that high). I realize this article wanted to push the SLI and crossfire video card configurations and see what kind of FPS they would get at that resolution, but the FPS graphs in this article should be set at 1920x1200 by default, not 2560x1600, since that resolution is useless to almost every gamer.7Enigma - Tuesday, February 24, 2009 - link
I think the point was to show that UNLESS you are running >24" monitors there is no REASON to have CF/SLI. I would normally agree with you but in this particular review I agree with the writer.I still think the broken line graphs showing all resolutions on the same x/y axis was more beneficial.