The Intel Kaby Lake-X i7 7740X and i5 7640X Review: The New Single-Threaded Champion, OC to 5GHz
by Ian Cutress on July 24, 2017 8:30 AM EST- Posted in
- CPUs
- Intel
- Kaby Lake
- X299
- Basin Falls
- Kaby Lake-X
- i7-7740X
- i5-7640X
Benchmarking 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.
All of our benchmark results can also be found in our benchmark engine, Bench.
7-Zip 9.2: link
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.
7z loves threads. 7z loves it.
WinRAR 5.40: link
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 is another benchmark like Agisoft, with some parts being serial and others multithreaded. When we compare the Core i7 to the Ryzen 7, the high ST performance helps push the Core i7 to the top despite the 2:1 thread deficit. On the other hand, the Core i5 has a 3:1 thread defecit to the Ryzen 5, and falls beneath it in the results.
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.
AES is an optimized problem for modern processors, so add frequency and cores to get a proportionally better result. Again, the Core i7-2600K and the Core i5-7640X are almost neck-and-neck.
HandBrake v1.0.2 H264 and HEVC: link
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.
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.
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.
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mapesdhs - Monday, July 24, 2017 - link
Ok, you get a billion points for knowing Commodore BASIC. 8)IanHagen - Monday, July 24, 2017 - link
Dr. Ian, I would like to apologize for my poor choice of words. Reading it again, it sounds like I accused you of something which is not the case.I'm merely puzzled by how Ryzen performs poorly using msvc compared to other compilers. To be honest, your finds are very relevant to anyone using Visual Studio. But again, I find Microsoft's VS compilar to be a bit of an oddball.
A few weeks ago I was running my own tests to determine wether my Core i5 4690K was up to my compiling tasks. Since most of my professional job sits on top of programming languages with either short compile times or no compilation needed at all, I never bothered much about it. But recently I've been using C++ more and more during my game development hobby and compile times started to bother me. What I found puzzling is that after running a few test I couldn't manage to get any gains through parallelism, even after verifying that msvc was indeed spanning all 4 threads to compile files. Than I tried disabling two cores and clocking the thing higher and... it was faster! Not by a lot, but faster still. How could it be faster with a 50% decrease in the number of active cores and consequently threads doing compile jobs? I'm fully aware that linking is single threaded, but at least a few seconds should be gained with two extra cores, at least in theory. Today I had the chance to compile the same project on a Core i7 7700HQ and it was substantially slower than my Core i5 4690K even with clocks capped to 3.2 GHz. In fact, it was 33% slower than my Core i5 at stock speeds.
Anyhow… Dr. Ian’s findings are a very good to point out to those compiling C++ using msvc that Skylake-X is probably worth it over Ryzen. For my particular case, it would appear that Kaby Lake-X with the Core i7 7740X could even be the best choice, since my project somehow only scales nicely with clocks.
I just would like to see the wording pointing out that Skylake-X isn’t a better compiling core. It’s a better compiling core using msvc at this particular workload. On the GCC side of things, Ryzen is very competitive to it and a much better value in my humble opinion.
As for the suggestion, I’d say that since Windows is a requirement trying to script something to benchmark compile times using GCC would be daunting and unrealistic. Not a lot of people are using GCC to work on the Windows side of things. If Linux could be thrown into the equation, I’d suggest a project based on CMake. That would make it somewhat easy to write a simple script to setup, create a makefile and compile the project. Unfortunately, I can not readily think of any big name projects such as Chromium that fulfill that requirement without having to meddle with eventual dependency problems as the time goes by.
Kevin G - Monday, July 24, 2017 - link
These chips edge out their LGA 1151 counter parts at stock with overclocking also carrying a slight razor edge over LGA 1151 overclocks. There are gains but ultimately these really don't seem worth it, especially in light of the fragmentation that this causes the X299 platform. Hard to place real figures on this but I'd wager that the platform confusion is going to cost Intel more than what they will gain with these chips. Intel should have kept these in the lab until they could offer something a bit more substantial.mapesdhs - Monday, July 24, 2017 - link
I wonder if it would have been at least a tad better received if they hadn't cripplied the on-die gfx, etc.DanNeely - Tuesday, July 25, 2017 - link
LGA2066 doesn't have video out pins because it was originally designed only for the bigger dies that don't include them; and even if Intel had some 'spare' pins it could use adding video out would only make already expensive mobos with a wide set of features that vary based on the CPU model even more expensive and more confusing. Unless they add a GPU to either future CPUs in the family (or IMO a bit more likely) a very basic one to a chipset variant (to remove the crappy one some server boards add for KVM support) keeping the IGP fully off in mainstream dies on the platform is the right call IMO.DrKlahn - Monday, July 24, 2017 - link
Great article, but the conclusion feels off:"The benefits in the benchmarks are clear against the nearest competition: these are the fastest CPUs to open a complex PDF, at the top for office work, and at the top for most web interactions by a noticeable amount."
In most cases you're talking about a second or less between the Intel and AMD systems. That will not be noticeable to the average office worker. You're much more likely to run into scenarios where the extra cores or threads will make an impact. I know in my own user base shaving a couple of seconds off opening a large PDF will pale in comparison to running complex reports with 2 (4 threads) extra cores for less money. I have nothing against Intel, but I struggle to see anything in here that makes their product worth the premium for an Office environment. The conclusion seems a stretch to me.
mapesdhs - Monday, July 24, 2017 - link
Indeed, and for those dealing with office work it makes more sense to emphasise investment where it makes the biggest difference to productivity, which for PCs is having an SSD (ie. don't buy a cheap grunge box for office work), but more generally dear god just make sure employees have a damn good chair to sit on and a decent IPS display that'll be kind to their eyes. Plus/minus 1s opening a PDF is a nothingburger compared to good ergonomics for office productivity.DrKlahn - Tuesday, July 25, 2017 - link
Yeah an SSD is by far the best bang for the buck. From a CPU standpoint there are more use cases for Ryzen 1600 than there is the i5/i7 options we have from HP/Dell. Even the Ryzen 1500 series would probably be sufficient and allow even more per unit savings to put into other areas that would benefit folks more.JimmiG - Monday, July 24, 2017 - link
The 7740X runs at a just over 2% higher clock speed than the 7700X. It can overclock maybe 4% higher than the 7700X. You'd really have to be a special kind of stupid to pay hundreds more for an X299 mobo just for those gains that are nearly within the margin of error.It doesn't make sense as a "stepping stone" onto HEDT either, because you're much better off simply buying a real HEDT right away. You'll pay a lot more in total if you first get the 7740X and then the 7820X for example.
mapesdhs - Monday, July 24, 2017 - link
Intel seems to think there's a market for people who buy a HEDT platform but can't afford a relevant CPU, but would upgrade later. Highly unlikely such a market exists. By the time such a theoretical user would be in a position to upgrade, more than likely they'd want a better platform anyway, given how fast the tech is changing.