Haswell-E Core i7-5820K Will Only Have 28 PCI-Express Lanes

As it turns out, and as we already suspected, not all of the Haswell-E CPUs will have the same number of PCI-Express lanes. Both the Core i7-5960X and the Core i7-5930K will be able to address 40 PCI-Express lanes, but the cheapest Core i7-5820K will only have access to 28 lanes. TechPowerUp forum member "623" has seemingly confirmed this through leaked manuals of Gigabyte's X99 motherboards.

CPU

Cores/Threads

Frequency

L3 Cache

PCI-Express Lanes

TDP

Expected Price

i7-5820K

6 / 12

3.3 GHz

12 MB

28

140 W

$400

i7-5930K

6 / 12

3.5 GHz

15 MB

40

140 W

$600

i7-5960X

8 / 16

3.0 GHz

20 MB

40

140 W

$1000+

Of course, this shouldn't come as too much of a surprise. Being able to grab a 6-core Haswell-E processor for the rumored price of $400 makes for a good deal, and there must be a concession made somewhere. While the Core i7-5960X and the Core i7-5930K will be able to address triple-GPU configurations with 16-16-8 lanes, the Core i7-5820K will only manage a 16-8-4 configuration, at best. This leaves the third GPU quite choked, and if you have any additional PCI-Express devices operating over lanes that are wired directly to the CPU, you will run into even more issues. We would have hoped that the i7-5820K would be able to address the slots in an 8-8-8 configuration; however, the manuals posted make no mention of such a configuration. Dual-GPU configurations won't present a problem, but for anything more than that you're going to want a Core i7-5930K or above.

Of course, you can't really ding Intel for doing this. The company will be offering a 6-core chip for hopefully under $400, and if you're interested in a multi-GPU setup that needs the extra PCI-Express lanes, you can probably afford the extra $200 for the upgrade to the Core i7-5930K anyway. Thus, if you're already playing around with the thought of acquiring a Haswell-E system with three or more GPUs, you'd better start adjusting your wishes or your budget.

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  • squirrelboy
    "and if you're interested in a multi-GPU setup that needs the extra PCI-Express lanes, you can probably afford the extra $200 for the upgrade to the Core i7-5930K anyway.

    No, cause you just spent all your money on a triple GPU setup ^^
    12
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  • squirrelboy
    "and if you're interested in a multi-GPU setup that needs the extra PCI-Express lanes, you can probably afford the extra $200 for the upgrade to the Core i7-5930K anyway.

    No, cause you just spent all your money on a triple GPU setup ^^
    12
  • maroon1
    12MB L3 for i7-5820K ?

    All the other sources I read say that it has 15MB L3
    3
  • CaedenV
    I would love something like this for my next build! Get one of these in a little mATX box that can only fit one GPU and you would never miss the extra PCIe lanes. If Intel is going to continue focusing on performance per watt instead of increasing raw horsepower then the only way up will be to go after CPUs with more cores anyways.
    0