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In Theory: How Does Lynnfield's On-Die PCI Express Affect Gaming?

Benchmark Results: Far Cry 2

If you look up the definition of CPU-limited in the dictionary, don’t be surprised if it comes up with a picture of our Far Cry 2 graph here. With one Radeon HD 4870 X2 installed, 2560x1600 is the only resolution able to exert enough strain to show a performance ding. Even with the platform limitation in place, we see the Core i7 on top, followed by Core i5, Core 2 Quad, and Phenom II.

Adding a second card exacerbates the bottleneck, and now 2560x1600 pulls even with the other resolutions. Of course, that doesn’t change the limiting factor at all, so the results fall into place exactly the same way.

Anti-aliasing helps spread the field out a bit, and we see more meaningful results. The Core i7-based setup edges out Core i5 at 1680x1050 and 1920x1200, but the two even out at 2560x1600 when only a single card is used. Core 2 Quad and Phenom II follow at the two lower resolutions, but are all fairly even at our most demanding setting.

Adding a second Radeon HD 4870 X2 shows mediocre gains across the board, largely a result of the CPUs we’re using here. At 2560x1600, the case for more graphics horsepower is definitely the strongest. And, as we’ve come to expect, Core i7 comes in first place, Core i5 scores second, Core 2 Quad finishes third, and Phenom II brings up the rear, still limited by platform performance.

  • megabuster
    AMD better have something up its sleeves or it's instakill.
    Reply
  • rambo117
    AMD... your loosing your game...
    Reply
  • dirtmountain
    A PhenomII x4 920? ouch
    Reply
  • bucifer
    I do not agree with the choices made in this article. You don't buy 2*4870x2 and the you slam a x4 920. The choices do not make sense.

    You should have used the best cpu(ex i7 920 oc@4GHz) to try to eliminate all bottlenecks and truly emphasize the limitations of x8/x16 pci-e lanes.

    The rest of the testing was done to include the new i5 which is not bad but not relevant for the bottleneck. I know many people would like to see how i5+p55 handles the gpu power but it's a highly unlikely scenario that someone would actually but such powerful and expensive cards on pair them with a cheaper cpu and a limited platform.

    I just think you should have tested things separately in different articles.
    Reply
  • radnor
    I know you used a 2.8Ghz Deneb for Clock-per-clock comparisons. MAkes sense. But a 2.8 Ghz Deneb is something really no unlocked. Ussually unlock versions go 3.5Ghz on stock VID, non BE PArts can reach 3.3Ghz safely.

    A 2.8 Deneb/Lynnfield/Bloomfield have completely diferent prices. You are comparing a R6 vs a R1. I7 is the Busa trouting everybody else. Of course the prices are very diferent.
    Reply
  • cangelini
    Gents, if you want to see the non-academic comparisons, I have the 965 BE compared in two other pieces for more real-world comparisons!
    http://www.tomshardware.com/reviews/intel-core-i5,2410.html
    and
    http://www.tomshardware.com/reviews/core-i5-gaming,2403.html
    Thanks for the feedback notes!
    Reply
  • bounty
    "Will Core i5 handicap you right out of the gate with multi-card configurations? The aforementioned gains evaporated in real-world games, where Core i7’s trended slightly higher, perhaps as a result of Hyper-Threading or its additional memory channel"

    Well you answered will i5 handicap you without hyperthreading, x8 by x8 and dual channel. It will by 5-10% If you wanted to narrow it down to memory channels, hyperthreading or the x8 by x8 you could have pice the game with the biggest spread and enabled each of those options selectively. Would have been kinda interesting to see which had the biggest impact.
    Reply
  • Shnur
    Great article! But then again... I don't see why a 955 wasn't used in this scenario... since the 920 is thing that nobody uses. Already that we know that i7 is superior to AMD flagship in multi-GPU configurations you're taking a crappy AMD CPU, buying a 790GX doesn't mean you're going to cut on the chip... and you're talking about who's performing better in 8x lanes... from my point of view it's a bad comparison, and there should have been a chip that'll be actually able to take a difference between 1 card and two and the from 16x and 8x.
    And thanks for the other linked reviews, but I'm not talking about comparing the chips themselves, I'm trying to figure out is 8x still good enough or I need to pay more for 16x?
    Reply
  • cangelini
    Shunr,
    Thanks much for the feedback--again, this wasn't meant to be about the CPUs, but the PCI Express links. If you want to know about the processors themselves at retail clocks, check out the gaming story, which does reflect x16/x16 and x8/x8 in the LGA 1366 and LGA 1156 configs.
    Hope that helps!
    Chris
    Reply
  • Shadow703793
    megabusterAMD better have something up its sleeves or it's instakill.lol! do you mean instagib?

    Joking aside, AMD needs something to counter this.
    Reply