Who Scales ... And Timing

In previous articles, we took a look at some stats on how many tests scale more or less than a certain threshold. Well, it gets a little trickier here to make sense of everything, so rather than pick points ourselves, we decided to list a bunch of them. In the chart below, we've listed the number of tests that fail to scale better than the percentage listed at the top of the column. Lots of tests fail to scale at what we would call a reasonable percentage, but people looking at these parts have a different definition of reasonable.

The maximum scaling percent is 100% just like with scaling from 1 to 2 GPU. But fewer games scale past 2 GPUs, and of those that do, fewer scale as near linearly past 2 GPUs. And to top that off, many tests that do scale at all scale right into a system limitation. A good chunk of games fail to scale past 5%, and fully 13 out of 18 tests fail to scale beyond 50% in each case we tested.

<2.5 <5 <10 <15 <20 <25 <33.3 <50
NVIDIA GeForce GTX 295 Quad SLI 5 5 6 7 8 9 10 13
NVIDIA GeForce 9800 GX2 Quad SLI 7 7 8 8 8 8 8 13
ATI Radeon HD 4870 1GB Quad CrossFire 5 5 5 7 9 11 12 13
ATI Radeon HD 4850 Quad CrossFire 6 7 9 10 10 10 12 13

Looking at the lower end we can see a bunch of tests fail to scale at all. Also, at 33%, many fewer situations scale at this rate than when moving from 1 to 2 GPUs. Clearly 4-way multiGPU solutions are not designed with anything but maximum performance in mind. Scaling isn't as important as the fact that these solutions can provide some degree of higher performance in some situations.

We would also like to note that when paying ridiculous amounts of money for not quite as ridiculous performance gains, the robustness of the solution is of very high importance. No one wants to pay over $1000 and get a solution that sometimes provides good scaling and sometimes degrades performance. Neither AMD nor NVIDIA are immune to this, but we would like to see this issue tackled in more earnest beyond simply noting that SLI and CrossFire can be disabled if trouble arises.

NVIDIA does have an advantage at this level though. We would love to see AMD get their driver act together and consistently have drivers that provide good scaling and performance in newly release AAA titles on launch day. We would also love to see them refine their driver development model in order to make sure that improvements released as hotfixes always make it into the very next WHQL driver released (which is currently not the case). Everywhere else, this is merely a slight annoyance that people may take or leave. At the highest of the high end, however, a delay in getting good scaling or the need to use less recent drivers that contain more recent fixes (and juggling which is which) can prove more than just a trifle. For such a high price, NVIDIA delivers a better experience on this count.

Additionally, until OpenCL matures, CUDA is a better GPU computing alternative to what AMD offers, and PhysX can provide additional flexibility now that more titles are beginning to adopt it. Actually, this is the space in which we currently see the most value in CUDA and PhysX, as those in the market for equipment this high end will be more interested in these niche features that don't have broad enough support or large enough current impact for us to heartily recommend them as a must have for everyone.

Technophiles (like myself) that are willing to put this kind of money into hardware often get excited about the hardware on a more than practical level. The technology itself, rather than the experience it delivers, can often be a source of enjoyment for the end user. I know I like playing with PhysX and CUDA in spite of the fact that these technologies still need broader support to compel the average gamer.

Performance, itself, cannot be ignored, and is indeed of the highest importance when it comes to the highest end configurations. We will include the value graphs, but we expect that the line closest to the top of the performance charts are the key factor in decision making when it comes to Quad GPU options. The troubles that come with maintaining a 4 GPU configuration are not worth it if the system doesn't provide a consistently top of the line experience.

What We Couldn't Cover Prices, Stutter and The Test
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  • Hattiwatti - Thursday, June 11, 2009 - link

    How 'bout if you'd overclock the prosessor to something like 4,0 GHz so it wouldn't be such a bottleneck to the Quad-SLI and Quad-CrossfireX configurations? I have tested it myself (with i7 920 and 2 GTX295's), and it really pays off. The performance increases a lot when CPU's clock is raised from 2,66 GHz to 3,8 GHz. It definitely makes a difference (NOTE: 3,6 GHz is still a bottleneck, and maybe 3,8 GHz is too. Couldn't overclock more and test since memory couldn't go any further)
  • marraco - Thursday, March 5, 2009 - link

    The price/performance charts favours the cheapest cards, but give little useful information.

    What really shows the price/performance information, is an XY chart with price vs performance.

    With it is easy to see what is the better performer at a given price, and the cheapest option at a given performance. Also shows closely related price/perfornmance options if you can't have access to the best performer, because is not available.

    and with XY charts is easy to see the best bang for the buck, because is commonly found at the sharp bending of the lower price evolvent line.
  • SiliconDoc - Wednesday, March 18, 2009 - link

    Let's hope the reviewers here take your information to heart and put it to use.
    I suspect though the FUD and bias will win out.
  • Dazzz - Tuesday, March 3, 2009 - link

    Although your article is really intresting, I would rather see some benchmarks including the people who it might also be interesting beside 30" display owners.

    Right know I'm thinking about purchasing a TrippleHead2Go after they updated the firmware and support 3x1680x1050.

    Unfortunately even widescreengaming forum can't provide FPS benchmarks for the 5040x1050 resolution.

    I'm thinking about going multiGPU but there is no comparison nvida and ati at this resolution.

    This article could have been the platform to support surroundgaming and show if 2/4way gpu's make sense in this context.


    I'm looking for such an comparison for 2 weeks now and couldn't find anything. And I'm still stuck with my decision if a single gtx295 could deliver a playable performance (disregarding the quality settings for the time beeing) or if I have to look for other sollution like 4way or 2way GTX285.

    Any suggestions ?



  • VooDooAddict - Tuesday, March 3, 2009 - link

    I very much like the resolution switching for the tables.

    This has confirmed what I'd been leaning towards for my next build (Shuttle X58 SFF). I'll be getting one of the following Dual GPU cards to run my 1920x1200 gaming.

    GTX295
    4870 X2
    4850 X2

    (I was running two 4850s in a X38 Shuttle SFF for a while before the frequent overheating caused me to switch to a single 4870.)
  • Antman56 - Sunday, March 1, 2009 - link

    I think that these Quad 4850 framerates need to have a special label. Using 512MB Radeon 4850s in Quadfire is not a good idea for 2560x1600. 1GB 4850s would have shown the 4850s high resolution muscle way better (as it did with the 4870 1GB cards vs 4870 512MB cards). Scaling would not be so poor.

    Otherwise, nice compilation of information. :p
  • TonkaTuff - Sunday, March 1, 2009 - link

    Best graph layout Ive seen on any site so far, so much easier to pick your desired resolution and have it in front of you instead of picking through a mess of resolutions,great article by the way still consider single card setups offer best bang for the buck and less headaches. So now multi GPU questions are out of the way, how about something regarding whats around the corner? 8,9 and gtx200 is all realistically the same architecture scaled up and shrunk down. Any whispers on new GPU architectures? Starting to feel that after the rush of technological progress the last few years especially ever since the release of 8000 series cards ( long time ago now!) things really seem to have stagnated the last few months. Cheers for a great read Jared.
  • DerekWilson - Monday, March 2, 2009 - link

    Thank you ;-)
  • Slappi - Sunday, March 1, 2009 - link

    I wouldn't touch their cards with a ten foot pole.

    They are about to collapse under their debt.
  • SiliconDoc - Wednesday, March 18, 2009 - link

    LOL - It's so much fun when a non-red rooster speculates like the raging red does all over the place.
    Thank you.
    Yes, ATI has bled BILLIONS the last couple of years, with barely over that in sales per year.
    It appears they're spending twice as much as they're selling, and that is probably not a recoverable situation - unless the new lib god Obama and the dem congress has a billion or two or more, "in the package" for them.

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