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
Let the memes collide, focus the memetic radiation, aim it at IBM and get them to jump into the x86 battle. :Ddgz - Monday, July 24, 2017 - link
Man, I could really use an edit button. my brain has shit itselfmapesdhs - Monday, July 24, 2017 - link
Have you ever posted a correction because of a typo, then realised there was a typo in the correction? At that point my head explodes. :DGlock24 - Monday, July 24, 2017 - link
"The second is for professionals that know that their code cannot take advantage of hyperthreading and are happy with the performance. Perhaps in light of a hyperthreading bug (which is severely limited to minor niche edge cases), Intel felt a non-HT version was required."This does not make any sense. All motherboards I've used since Hyper Threading exists (yes, all the way back to the P4) lets you disable HT. There is really no reason for the X299 i5 to exist.
Ian Cutress - Monday, July 24, 2017 - link
Even if the i5 was $90-$100 cheaper? Why offer i5s at all?yeeeeman - Monday, July 24, 2017 - link
First interesting point to extract from this review is that i7 2600K is still good enough for most gaming tasks. Another point that we can extract is that games are not optimized for more than 4 core so all AMD offerings are yet to show what they are capable of, since all of them have more than 4 cores / 8 threads.I think single threading argument absolute performance argument is plain air, because the differences in single thread performance between all top CPUs that you can currently buy is slim, very slim. Kaby Lake CPUs are best in this just because they are sold with high clocks out of the box, but this doesn't mean that if AMD tweaks its CPUs and pushes them to 5Ghz it won't get back the crown. Also, in a very short time there will be another uArch and another CPU that will have again better single threaded performance so it is a race without end and without reason.
What is more relevant is the multi-core race, which sooner or later will end up being used more and more by games and software in general. And when games will move to over 4 core usage then all these 4 cores / 8 threads overpriced "monsters" will become useless. That is why I am saying that AMD has some real gems on their hands with the Ryzen family. I bet you that the R7 1700 will be a much better/competent CPU in 3 years time compared to 7700K or whatever you are reviewing here. Dirt cheap, push it to 4Ghz and forget about it.
Icehawk - Monday, July 24, 2017 - link
They have been saying for years that we will use more cores. Here we are almost 20 years down the road and there are few non professional apps and almost no games that use more than 4 cores and the vast majority use just two. Yes, more cores help with running multiple apps & instances but if we are just looking at the performance of the focused app less cores and more MHz is still the winner. From all I have read the two issues are that not everything is parallelizable and that coding for more cores/threads is more difficult and neither of those are going away.mapesdhs - Monday, July 24, 2017 - link
Thing is, until now there hasn't been a mainstream-affordable solution. It's true that parallel coding requires greater skill, but that being the case then the edu system should be teaching those skills. Instead the time is wasted on gender studies nonsense. Intel could have kick started this whole thing years ago by releasing the 3930K for what it actually was, an 8-core CPU (it has 2 cores disabled), but they didn't have to because back then AMD couldn't even compete with mid-range SB 2500K (hence why they never bothered with a 6-core for mainstream chipsets). One could argue the lack of market sw evolvement to exploit more cores is Intel's fault, they could have helped promote it a long time ago.cocochanel - Tuesday, July 25, 2017 - link
+1!!!twtech - Monday, July 24, 2017 - link
What can these chips do with a nice watercooling setup, and a goal of 24x7 stability? Maybe 4.7? 4.8?These seem like pretty moderate OCs overall, but I guess we were a bit spoiled by Sandy Bridge, etc., where a 1GHz overclock wasn't out of the question.