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Intel Core i9-7900X ‘Skylake-X’ 10C20T CPU Indepth Analysis

Cinebench

Cinebench is an application which renders a photorealistic 3D scene to benchmark a computer’s rendering performance, on one CPU core, all CPU cores or using the GPU. We run the test using the all-core CPU and single-thread CPU modes.


Handbrake Conversion

Handbrake is a free and open-source video transcoding tool that can be used to convert video files between different codecs, formats and resolutions. We measured the average frame rate achieved for a task of converting a 6.27GB 4K video using the Normal Profile setting and MP4 container. The test stresses all CPU cores to 100% and shows an affinity for memory bandwidth.

x265 Encoding

x265 Encoding tests system performance by encoding a 1080p test file using the x265/HEVC format.

Overview:

Multi-threaded performance from the Core i9-7900X is superb. There’s no other way of putting it. In Cinebench multi-threaded, the Skylake-X 10-core chip is 21% faster than the Core i7-6950X it replaces at stock frequencies and 13% with both processors overclocked. Switch focus to Ryzen 7 1800X, and the i9-7900X is 33% faster at stock and 38% better when overclocked. Single-threaded performance also shows Skylake-X in a positive light thanks to its high clock speeds and modern architecture.

Handbrake performance for the 7900X is strong but the chip’s tendency to reduce its frequency to 3.6GHz during conversion resulted in reduced performance against an overclocked 6950X. We saw similar frequency reduction characteristics from the 6950X and this is a testament to the stress placed on CPUs by Handbrake. Compared to the 6950X, the i9-7900X is 22% faster at stock and 9% quicker when overclocked. Skylake-X’s 10-core beats Ryzen 7 1800X by 39% at stock and 49% when overclocked.

The x265 encoding benchmark rewards clock speed on multi-threaded CPUs, hence why Ryzen 7 gets so close to the performance of the 7900X. Compared to the Broadwell-E 10-core chip, Core i9 is 20% faster at stock and 19% quicker with both overclocked. Ryzen 7 shows solid performance but the 10-core 7900X is 17% quicker at stock and 39% better with both overclocked.

If you are looking for a multi-threaded beast, Intel’s new Core i9-7900X is just that. It puts a beating on every other CPU in our charts at stock, and only the Broadwell-E i7-6950X can show competitive performance when heavily overclocked.

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  • Syed Muhammad Sanabil

    Good review . Honestly even if Intel gets all the goodness of being a fast processor its highly priced. Also poor thermal performance is a big deal because processor eventually runs hot and performance will take a toll.
    I am personally waiting for Threadripper AMD’s line up to compete with Intel’s half cooked CPU.If AMD TH has good price and good thermal efficiency then even if it is a bit slower then Intel’s offering people will go for it. Ryzen 7 and especially Ryzen 5 1600 cpu proved this already

  • Dennis Achterberg

    What about VRM temperatures? 🙂

  • Lelisevis

    This is a review of the CPU. The VRM temps are going to vary depending on the board and its overly extravagant but largely useless cooling shroud.

  • vasras

    Brilliant and thorough review, thank you very much.

    I’d be happy with quad memory-channel i7-7740X with 44 PCI-e lanes. Fast enough for _everything_ I need, and would have enough memory and PCI-express bandwidth for the workloads I run (don’t need 10c/20t).

    Unfortunately, it doesn’t exist. Either I have to buy the crippled i7-7740x with 28 PCIe and dual channel memory OR I have to buy the over-priced space heater that is the 7900X with a motherboard that fries eggs with the VRMs and sucks so much electricity out of the socket that I can hear the kill-o-watt whirr like crazy in the background while notes keep flying out of my wallet.

    No thanks Intel. You really outdid yourself this time around.

    I will wait for the ThreadRipper from AMD.

  • Michał Kubiak

    I like your test, but let me make a small correction, 7900X is faster then Ryzen only because of more cores and higher clock, not due to “modern architecture” (which while newer? then Ryzen is by no means better). But to count my chickens 🙂 Ryzen_OC is 4.05Ghz, 7900X_OC is 4.6Ghz
    1776*1.25(because Intel has 25% more cores then AMD)=2220
    now to equalize core speeds: 2220*4.6/4.05=2521 (the Ryzen score as it would be at 4.6Ghz) – IPC wise Intel (scored 2449) is still a bit worse then AMD in Cinebench.
    I’m not saying that AMD is better since it can’t at the moment reach 4.6Ghz nor does it have 10 core CPU to fight with.
    Similar thing happens with x265 encoding benchmark: 30,6*1,25*4,6/4,05=43,4444444 – a bit faster then Intel. And it is all in tasks that put use to AVX2 and there is still Intel advantage in 4 channel memory.

  • Michał Kubiak

    Well, at least you can wait a bit and see if Threadripper is actually better then Intel – there is no guarantee it is. Especially for lightly threaded tasks that you speak of (that per chance require high core clock that will most likely not be reachable on TR).

  • AMDs single core IPC is slightly worse than Intels, but AMDs implementation of SMT vs Intels HT brings it out on top by a slight margin at the same core/clocks in multi threaded benchmarks while losing in the single core benches. And then AMD doesn’t really OC well, neither does memory clock up well, its improving of course but not at any great pace.

  • roadkill612

    Bottom line w/ Ryzen is mem clocks pf 2933 are a no brainer, and known to work 3200 components are common.

    Thats the consensus on the street.

  • roadkill612

    A pact with the devil will always bite u in the ass.

    How can u trust intel?

    Buy a $999 cpu w/ scads of lanes, & discover there is an charge to use nvmeS as they should be. Slimy.

    The new keying system shows they use their research dollars to effect better ways of screwing customers. A good look guys.

    I would buy amd gear if same money and 10% worse. My time, upgradeability, conscience and dignity are worth something too, thanks intel.

    AMD probably are 10% worse in the criteria intel like to use, but AMDs modular/fabric architecture, is miles better than intel has or will have achitecture, for future cost effective ~equivalent outcomes.

    BTW the prices u list for amd dont reflect reality. Both are much cheaper on amazon etc. Further, the widely regarded sweet spot is the 12 thread r5 1600, at ~$220

    Lanes are just sufficient on ryzen, for a 16 lane gpu, a 4 lane nvme ssd onboard and a 4 lane pcie2 nvme ssd (~1.6GBps, or triple a sata ssd).. Beyond that, u have stacks of sata and .5GBps pcie2 expandability, but no 1GBps pcie3 lanes

    note also, amd pcie3 lanes are direct to the cpu, not via switches and bridges like most intels.

  • Christopher Lennon

    Newsflash, the i7-7740X only has 16 PCIe Lanes, not 28!

  • Javier Saove

    Test w/ agesa 1006 please…..

  • 1011101001001

    Not sure why you would complain about a crippled quad core and decide to wait for a 10 core minimum threadripper lol. Amd has some amazing stuff coming out, but it will not have the IPC of intel.
    The 8 core intel is actually a pretty sweet chip. It can overclock 2 of its best cores to 4.5 ghz for single or two thread tasks and 4.3 turbo on all cores. The thermal is only an issue when overclocking and when you get this many cores it will always be a problem when overclocking. Amd hasnt been able to go over 4.1 ghz yet.

  • janon

    Intel PCIE lanes are direct to the cpu as well. And if intel says a cpu has 16 lanes (like the 7700k) then those are dedicated to the GPU. The rest, in that case, come from the chipset via dmi 3. This is unlike AMD who is currently *overstating* PCIE lanes available for video. Sorry to burst your fanboy delusion bubble

  • janon

    I strongly suspect nothing you do requires 44 PCIE lanes or quad channel RAM. People complaining
    about 7900x, and somehow not satisfied with *either* Kaby Lake *or* Ryzen 5/7, and obsessing instead over “Thread Ripper” sound generally clueless.

    AMDs marketing is really working for TR. Somehow every hump on comment threads is now convinced they’re doing all sorts of things that somehow justify *32 threads*, even at lower IPC, and *dozens* of PCIE lanes and *mountains* of memory bandwidth. Enormously unlikely.