Core i7: 4-Way CrossFire, 3-way SLI, Paradise?

Caveats, Realism, And Driver Hell

Intel’s X58 chipset gives us the opportunity to make gaming comparisons never before possible given its support for CrossFireX and SLI. We were understandably very excited about what this meant for the latest multi-card rendering technologies. Of course, in an ideal world, this would have also meant a smooth, relaxing testing scenario as we swapped graphics cards in and out, uninstalling and reinstalling drivers as we went. Unfortunately, that’s a gross oversimplification of how things go in a lab.

Quad CrossFireX--four RV770s, 2GB of GDDR5, and fire-breathing blowers.

The first thing to bear in mind when it comes to dealing with a pile of the highest-end hardware is that it all runs surprisingly hot—so much so that it becomes necessary to let the various configurations sit for a few minutes before swapping hardware to avoid burns. In any of these platforms, a single Radeon HD 4870 or GeForce GTX 280 easily keeps up with the thermal situation by spinning onboard blowers up to cope with demanding 3D workloads. A single Radeon HD 4870 X2—representing our 2 x Radeon HD 4870 scores—is similarly capable of scaling fan speed on its own. Two GeForce GTX 280s even behave well enough, given the two slots between cards encouraged by Nvidia’s rigid SLI connector. But when you shift over to 3-way SLI, with three cards smashed up against each other, or quad-CrossFireX using a pair of Radeon HD 4870 X2s side-by-side, temperatures quickly get out of hand and easily cause stability issues. As a general rule, we took matters into our own hands while using four-way CrossFireX and 3-way SLI by installing RivaTuner or using the Catalyst 8.10 drivers to manually adjust fan speed. The side effect is an unfortunate amount of noise. Such is the price you pay to play.

Drowning In Drivers

Then there’s the issue of drivers and recently released games. In talking to a handful of folks over at AMD, had we had access to Core i7 and X58 back in July, we could have dropped Radeon HD 4800-series cards into the platform and run CrossFire mode. The platform support was already there, ready to go. And yet, in the past two weeks, we’ve received three official driver updates to improve performance. AMD says it isn’t trying to frantically patch in support for the platform, but we’ve certainly been frantically testing and re-testing in order to keep up with its steady stream of “faster” drivers optimized for just a handful of games that weren’t performing as well as the company had hoped.

3-way SLI: Kiss your expansion slots goodbye and don't touch the metal--it burns!

The situation with Nvidia has been much smoother. But even there we have a scheduled roll-out of software that isn’t quite ready. First, the company made its GeForce 180.43 beta driver set available, adding support for SLI on X58. Currently, those drivers only include partial support for what will eventually be the final GeForce 180 release, set to include multi-monitor SLI and the ability to designate a GPU for PhysX processing. As of the Core i7 embargo, those features are still not available

Keep each company’s respective software position in mind as your peruse the benchmarks. There are a number of results where something is clearly amiss, and we’ll happily identify some of the stranger scores.

Intel Tempers Expectations

Back at IDF, Intel sat us down in a small-group session to show off some preliminary Core i7 benchmark scores and share the details of what it would ship come launch time. We knew the top-end part would run at 3.2 GHz. We knew Intel’s own DX58SO motherboard would clumsily present three channels of memory across four slots (and we know that the enthusiast-minded reps within the company aren’t necessarily pleased about the board’s setup). And by the end of Intel’s presentation, we already had a good idea of where its architecture would excel and where it would fall short as a result of design compromises.

You see, Intel’s Core 2 micro-architecture employed a large, shared L2 cache—the top-end Penryn-based Wofldales consisted of two cores dynamically accessing 6 MB of very fast memory. Core i7 gives each of four cores its own 256 KB L2 cache and a much larger (and slower) shared 8MB L3. As a result of the new cache architecture (and re-introduction of Hyper-Threading), Core i7 desktop chips chew through encoding apps much faster than ever before. But they don’t present the sort of improvements that would accelerate gaming. Intel let us in on this bit of information back at IDF, tempering our expectations of what to expect by claiming whatever speed-ups we did see would be a product of the processor’s Turbo mode pushing quicker clock speeds.

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  • randomizer
    SLI scales so nicely on X58.
  • DFGum
    Yep, i hafta say being able to switch brands of graphics cards on a whim and selling off the old is great. Knowing im going to be getting the preformance these cards are capable of (better price to preformance ratio) is nice also.
  • cangelini
    randomizerSLI scales so nicely on X58.

    Hey you even got a "First" in there Randomizer!
  • randomizer
    cangeliniHey you even got a "First" in there Randomizer!

    And modest old me didn't even mention it. :lol:
  • enewmen
    Still waiting for the 4870 X2s to be used in these bechmarks. I thought THG got a couple for the $4500 exteme system. But still happy to see articles like this so early!
  • cangelini
    enewmenStill waiting for the 4870 X2s to be used in these bechmarks. I thought THG got a couple for the $4500 exteme system. But still happy to see articles like this so early!

    Go check out the benchmark pages man! Every one with 1, 2, 4 4870s. The 2x and 4x configs are achieved with X2s, too.

    Oh, and latest drivers all around, too. Crazy, I know! =)
  • enewmen

    I found it, just read the article too quickly. - My bad.
    "A single Radeon HD 4870 X2—representing our 2 x Radeon HD 4870 scores—is similarly capable of scaling fan speed on its own. "
    Hope to see driver updates like you said.
  • spyde
    Hi there, my question regarding these benchmarks with the HD card is, "was a 2G card use or a 1G". I am about to buy a new system and was looking to buy 2 x HD4870X2 2G cards, but with these results its looking a bit ify. I hope you can answer my question.
  • Proximon
    That's a nice article. I especially like the way the graphs are done. everything is scaled right, and you get an accurate representation.
  • cangelini
    These are 2GB cards =)
  • spyde
  • Tjik
    How sure can we be that the difference between a nVidia and an AMD setup isn't related to the motherboard design? From the figures I would make the conclusion that the AMD + AMD setup is able to overcome some of the disadvantages of a weaker CPU, and in several cases there's no obvious - at least to me - reason why a Core i7 with the same single or dual set of AMD graphic cards would perform worse. It's easy to blame it on driver issues, but what proof is there to make that a more plausible conclusion? I'm not into some kind of weird conspiracy theory, I'm just technically curious to know why we should assume the X58 platform to be flawless when figures suggest differently.

    The conclusion I draw from this and other tests made is that Core i7 is great, but you need to spend big money on graphic cards to make it a gamers choice, or put it into a game performance per money perspective. As it is now, before future releases of mid range CPUs, or if AMD unexpectedly release some scary monster, I foremost see Core i7 as a solid solution for serious work. In rendering and other CPU dependent tasks it might be a blessing to cut some 40 % of the time to process.

    Another observation is that if the current scenario doesn't change in the near future we could well be back to old school over-clocking culture, when money and availability set the limits. I'm not against but in the last years we've seen more of a yuppie's over-clocker culture, where money and availability haven't been an issue. To be frank, what we have here is two ways of making priorities: one option is an AMD system which gives you a 790FX motherboard + CPU + RAM for the same price as a single Intel Core i7, and if you're not planning to play at resolutions higher than 1600x1200 and probably not buy anything above a possible single X2 Graphic Card it could well be the best offer for the money.

    Options are good and even with AMD well behind it opens up for many different choices. Some never really use but enjoy knowing they got a monster system, others only buy exactly what gives best value for money, some specialize systems for tasks with a cost conscious approach, and some don't have a clue. Every choice is good as long as the user is happy (and spendings doesn't hurt the family economy).

    Oh, a lot of text there. In conclusion I'm more interested in whether the X58 platform is ill suited (or less good) for AMD graphic cards at the moment, and for proof either way.
  • Anonymous
    hi guys,

    nice @ first : )

    but now i got one big question about this review

    on page 12 you got a nice overview about the 3d mark benchmark

    what i don't understand is the CPU score of the i7 and c2q ex based on nvidia and ati graphic boards

    there is such a huge difference of the cpu score just because of changing graphic boards ???

    how can that be?

    i mean the cpu score is based on the cpu right? or does futuremark test
    something else with this cpu score than just the cpu itself?

    i don't get to see the reason, why just changing from nvidia to ati or otherwise could have such huge effect on that cpu score

    but maybe one of you could explain it to me, otherwise i could think there is something wrong with this or maybe all of these benchmarks in this review

    thx in advance : )
  • arkadi
    well finally we getting more and more info about the i7, i guess it will take us few weeks 2 get it all right.I just love it when new staff comes out :)
  • aznguy0028
    "there is such a huge difference of the cpu score just because of changing graphic boards ???"

    it was stated in the article on that page, at the top. the default run with PhysX artificially inflates the scores.
  • z999
    lolz, there are some crazy problems w/ the ATI cards... like turning on AA and gaining 50FPS...
    You should do this benchmark again in a couple of months when the drivers give more accurate results, and in that one..... lose the phenom :P.
  • chaohsiangchen
    Nice job well done! Thanks for the article.

    However, I didn't see specified CPU clocks, so I presume that all three CPUs tested were run at stock speed. Although I have little doubt that Phenom X4 will still lose to both Ci7 965EE and QX9770, it's just my curiocity to see how Phenom X4 at 3.2GHz would perform.
  • zodiacfml
    I thought there will be little difference between core 2 and i7 in games, so it was just the graphics card that is holding i7 back in games. in my mind, i thought a single gtx 280 was held back by the fastest core2, wasting graphics power which was not the case here.

    i7 is really a cool system, much like the intel SSD. intel is on fire. :)
  • bunnyblaster
    I've been an avid Toms Hardware reader for over 8 years now. This is my first post. It is an issue that has been nagging me the last few updates for Tomshardware. The "page scrolling function" on each page is terribly designed. I find it slow, disappears before I select the page and sometimes does not register at all. I have multiple computers and I draw the same conclusion on all of them. It gets rather annoying when I just want to read some implications or conclusions of some reviews and I can't get there easily without going through 27 pages.

    Why not just revert to the system everyone else uses with a simpler scroll-down bar?
  • fahdriyami
    What a surprise, no Flight Simulator X Benchmarks