What We Couldn't Cover

Our tests will include the GeForce GTX 295 Quad SLI, GeForce 9800 GX2 Quad SLI, Radeon HD 4870 1GB Quad CrossFireX, and Radeon HD 4850 Quad CrossFireX. We were unfortunately not able to test the 4850 Quad with 1GB per GPU because we didn't have 2 of the 4850 X2 2GB cards. This would undoubtedly have made the 4850 look a little stronger in Quad at 2560x1600 (where it really counts). While it wouldn't compete for the highest end performance, the higher memory Quad 4850 is certainly of interest to us after seeing the value in two of them. But we really don't expect any Quad option to deliver on bang for buck metrics.

Past that, we also didn't include Race Driver GRID this time around. Due to our continuing issue with FRAPS, we couldn't record performance data for either of our Quad NVIDIA solutions. We didn't feel that presenting the data from the game with just AMD hardware was highly useful, but it is worth mentioning that just looking at the numbers we could tell that the Quad NVIDIA solutions performed slower than the AMD solutions. I do apologize for a lack of quantitative data, but sometimes that's how it goes. We will continue to try and collect this data and we may do something with it down the line if we are successful.

Our first article explored 1 to 2 GPUs. The second looked at 1 to 3 and 2 to 3 GPUs. This one only focuses on the performance improvement from 2 to 4 GPUs. The reason for this is that there are no single GPU versions that exactly match half a GTX 295 or half a 9800 GX2. We can see when things don't scale and how they scale differently from 3 way by looking back at the previous article if people want, so having a lopsided analysis that included some metrics for AMD and not NVIDIA didn't seem quite right.

Just like the diminished returns we saw when moving from 2-way to 3-way, we see more diminishing returns when moving from 3-way to 4-way. The way we can get a feel for that more directly is that we see much less scaling when moving from 2-way to 4-way than when moving from a single GPU to two (even though the theoretical performance improvement is the same).

This time around, we didn't zero the value data when performance didn't meet a threshold. We know some people liked that way of doing it, but value really isn't a focus of a 4-way GPU shootout anyway, so we feel that the data is more academic on its face. This article rounds out our data and has all the performance numbers for all the parts we've looked at, while our analysis focuses on 4-way. We are still actively refining our approach to representing value moving forward, so your feedback is not only welcome, it is greatly appreciated.

Index Who Scales ... And Timing


View All Comments

  • 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) Reply
  • marraco - Thursday, March 05, 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 03, 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 03, 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.

    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 01, 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 01, 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. Reply
  • DerekWilson - Monday, March 02, 2009 - link

    Thank you ;-) Reply
  • Slappi - Sunday, March 01, 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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