The Intel Skylake-X Review: Core i9 7900X, i7 7820X and i7 7800X Tested
by Ian Cutress on June 19, 2017 9:01 AM ESTBenchmarking Performance: CPU Encoding Tests
One of the interesting elements on modern processors is encoding performance. This includes encryption/decryption, as well as video transcoding from one video format to another. In the encrypt/decrypt scenario, this remains pertinent to on-the-fly encryption of sensitive data - a process by which more modern devices are leaning to for software security. Video transcoding as a tool to adjust the quality, file size and resolution of a video file has boomed in recent years, such as providing the optimum video for devices before consumption, or for game streamers who are wanting to upload the output from their video camera in real-time. As we move into live 3D video, this task will only get more strenuous, and it turns out that the performance of certain algorithms is a function of the input/output of the content.
HandBrake H264 and HEVC
As mentioned above, video transcoding (both encode and decode) is a hot topic in performance metrics as more and more content is being created. First consideration is the standard in which the video is encoded, which can be lossless or lossy, trade performance for file-size, trade quality for file-size, or all of the above can increase encoding rates to help accelerate decoding rates. Alongside Google's favorite codec, VP9, there are two others that are taking hold: H264, the older codec, is practically everywhere and is designed to be optimized for 1080p video, and HEVC (or H265) that is aimed to provide the same quality as H264 but at a lower file-size (or better quality for the same size). HEVC is important as 4K is streamed over the air, meaning less bits need to be transferred for the same quality content.
Handbrake is a favored tool for transcoding, and so our test regime takes care of three areas.
Low Quality/Resolution H264: He we transcode a 640x266 H264 rip of a 2 hour film, and change the encoding from Main profile to High profile, using the very-fast preset.
More cores, more frequency, more IPC, more fun: the Core i9-7900X wins here, and even the i7-7800X wins out against the Core i7-6900K.
High Quality/Resolution H264: A similar test, but this time we take a ten-minute double 4K (3840x4320) file running at 60 Hz and transcode from Main to High, using the very-fast preset.
Moving into HQ mode means making the job more parallel, so the higher core counts stay at the top of the chart.
HEVC Test: Using the same video in HQ, we change the resolution and codec of the original video from 4K60 in H264 into 4K60 HEVC.
WinRAR 5.40
For the 2017 test suite, we move to the latest version of WinRAR in our compression test. WinRAR in some quarters is more user friendly that 7-Zip, hence its inclusion. Rather than use a benchmark mode as we did with 7-Zip, here we take a set of files representative of a generic stack (33 video files in 1.37 GB, 2834 smaller website files in 370 folders in 150 MB) of compressible and incompressible formats. The results shown are the time taken to encode the file. Due to DRAM caching, we run the test 10 times and take the average of the last five runs when the benchmark is in a steady state.
WinRAR loves having access to all the caches as much as possible, to prefetch and store data as needed. The Skylake-X chips fall back a bit here, even with DDR4-2666 support. The Core i7-7800X uses DDR4-2400 memory, so puts it further behind. Interesting didn't realise that the lower core count Broadwell-E chips were affected so much by this test, and the higher core count Ivy Bridge-E parts are faster here.
AES Encoding
Algorithms using AES coding have spread far and wide as a ubiquitous tool for encryption. Again, this is another CPU limited test, and modern CPUs have special AES pathways to accelerate their performance. We often see scaling in both frequency and cores with this benchmark. We use the latest version of TrueCrypt and run its benchmark mode over 1GB of in-DRAM data. Results shown are the GB/s average of encryption and decryption.
7-Zip
One of the freeware compression tools that offers good scaling performance between processors is 7-Zip. It runs under an open-source licence, is fast, and easy to use tool for power users. We run the benchmark mode via the command line for four loops and take the output score.
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jjj - Monday, June 19, 2017 - link
The 10 cores die is clearly 320+mm2 not 308mm2. The 308mm figure rounds down the mm based on those GamerNexus pics. From there, you slightly underestimate the size of other 2 die.Sarah Terra - Monday, June 19, 2017 - link
Fair point but what I take from this review is that you are going to be spending pretty much double the cost or higher of ryzen for a proc that will have a 30% larger power envelope if you want higher performance. Intel is scrambling here, well done AMD.jjj - Monday, June 19, 2017 - link
With 8 cores and up, thermal is a big issue when you OC Skylake X.. Power also to some extent.The 6 cores looks interesting vs the 7700k but not so much vs anything else. CPU+mobo gets you north of 600$ and that's a lot. If it had all the PCIe lanes enabled, there would be that but ,while plenty will buy it, it makes no sense to. And ofc there should be a Coffee Lake 6 cores soon , we'll see how it is priced- in consumer 6 cores with 2 mem chans is fine.
More than 6 cores are priced way too high and , if you need many cores, you buy for MT not ST so ST clocks are less relevant.
Intel moving in the same direction as AMD on the cache size front is interesting- larger L2 and smaller L3. Now they have "huge cache and memory latency issues"" just like Ryzen lol.
W/e, Intel's pricing is still far too high and this platform remains of minimal relevance.
ddriver - Monday, June 19, 2017 - link
Funny thou, when Ryzen under-performed in games that was no reason to not publish gaming benches, in fact being the platform's main weakness there was actually emphasis put on that... but when it comes to intel we gotta have special treatment... Let's hear it for objectivity!Granted the 7800X finally brings something of relatively decent value, but still no good reason to justify the purchase unless one insists on an intel product, for the brand, for thunderbolt or hypetane support.
"To play it safe, invest in the Core i9-7900X today."
Really? With Threadripper incoming in a matter of weeks? For less than 1000$ you will get 16 zen cores. It will definitely beat the 7900X by a decent margin in terms of performance, plus the massive I/O capabilities and also ECC support, which I'd say is vital. That just doesn't sound like a honest recommendation. Not surprising in the least.
ddriver - Monday, June 19, 2017 - link
Also, on top of that we have launch prices for Ryzen rather than current prices. Looks like a rather open attempt to diminish AMD's platform value.Ian Cutress - Tuesday, June 20, 2017 - link
We've always posted manufacturer MSRPs in our CPU charts. There has been no official price drop from AMD; if you're seeing lower, it's being run from the distributor level.On the TR issue, we basically haven't tested it and don't know the price. Lots of variables in the air, which is why the words are /if you want to play it safe/. Safe being the key word there.
ddriver - Tuesday, June 20, 2017 - link
Dunno Ian, in my book this sounds more like hasty than safe. The safe thing would be to wait out. Even without the incipient TR launch, early adoption is rather unsafe on its own. As it is, it sounds more like an attempt to dupe people into spending their money on intel in the eve of the launch of a superior value and performance product from a direct (and sole) competitor.It is true that nothing is still officially known about TR, but based on the ryzen marketing strategy and performance we can make safe and accurate speculations. I expect to see the top TR chip launched at 999$ offering at the very least 30% of performance advantage over the 7900X in a similar or slightly higher thermal budget, of course in workloads that can scale nicely up with the core count.
Comparing the 7900X to the 1800X, we have ~35% performance advantage for 205% the price and 150% the power usage. Based on that, it is a safe bet that TR is going to shine.
fanofanand - Monday, June 26, 2017 - link
Ian is a scientist, the less guessing the better. Give him an opportunity to review TR before giving suggestions. Doesn't that seem fair?t.s - Tuesday, June 20, 2017 - link
Play it safe? Really?? Please. As if everyone in this world's stupid.Ranger1065 - Wednesday, June 21, 2017 - link
There has never been a better time to give Intel the middle finger.