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 Web Tests
One of the issues when running web-based tests is the nature of modern browsers to automatically install updates. This means any sustained period of benchmarking will invariably fall foul of the 'it's updated beyond the state of comparison' rule, especially when browsers will update if you give them half a second to think about it. Despite this, we were able to find a series of commands to create an un-updatable version of Chrome 56 for our 2017 test suite. While this means we might not be on the bleeding edge of the latest browser, it makes the scores between CPUs comparable.
All of our benchmark results can also be found in our benchmark engine, Bench.
SunSpider 1.0.2: link
The oldest web-based benchmark in this portion of our test is SunSpider. This is a very basic javascript algorithm tool, and ends up being more a measure of IPC and latency than anything else, with most high-performance CPUs scoring around about the same. The basic test is looped 10 times and the average taken. We run the basic test 4 times.
SunSpider has a single threaded focus, and we see the Kaby Lake-X processors take their spots at the top of the graph.
Mozilla Kraken 1.1: link
Kraken is another Javascript based benchmark, using the same test harness as SunSpider, but focusing on more stringent real-world use cases and libraries, such as audio processing and image filters. Again, the basic test is looped ten times, and we run the basic test four times.
Mozilla too relies on single threaded IPC and frequency.
Google Octane 2.0: link
Along with Mozilla, as Google is a major browser developer, having peak JS performance is typically a critical asset when comparing against the other OS developers. In the same way that SunSpider is a very early JS benchmark, and Kraken is a bit newer, Octane aims to be more relevant to real workloads, especially in power constrained devices such as smartphones and tablets.
Octane is an interesting benchmark, requiring cores and ST performance, but mostly the latter. It also seems that either Intel's design is optimized for the benchmark or vice versa, given the substantial difference in performance. There's no way for the benchmark to use all of the threads from AMD, nor the 12 threads in the Core i7-7800X which has a lower single thread performance.
WebXPRT 2015: link
While the previous three benchmarks do calculations in the background and represent a score, WebXPRT is designed to be a better interpretation of visual workloads that a professional user might have, such as browser based applications, graphing, image editing, sort/analysis, scientific analysis and financial tools.
WebXPRT is a mix of ST and MT, but still based in the web and relies on ST performance a lot. Given the variable loading on the benchmark, Intel's newest features such as Speed Shift help keep it at the top.
176 Comments
View All Comments
MrSpadge - Monday, July 24, 2017 - link
> realize that overclocking may not be appropriate for these workloadsThat's going too far. Just don't overclock as far for heavy AVX usage.
MrSpadge - Monday, July 24, 2017 - link
Kind of agreed. Ian, you should log the clock speeds during benchmark runs and check for anomalies. The chip or mainboard could throttle, or your 4.0 GHz AVX clock could just be way too low. What's the default AVX clock? Maybe 4.4 GHz? That would pretty much match the 10% performance degradation.Ian Cutress - Monday, July 24, 2017 - link
I need to do a performance scaling piece, I know. It's on the to-do listKvaern1 - Monday, July 24, 2017 - link
As already mentioned it's heavy AVX workloads which makes it throttle when OC'ed. The same thing happens on OC'ed Skylakes.arh2o - Monday, July 24, 2017 - link
Something seems wrong with the 7700k results vs the 7600k results. How is the 7600k beating the 7700k so handily in all the games? Are you sure the graphs are not swapped? ROTR shows the 7600k beating the 7700k by 20 FPS which seems impossible considering most reviews on this game have the 7700k on top of the 7600k.ydeer - Monday, July 24, 2017 - link
I would have liked to see some idle power consumption numbers because my PC is always on.Ro_Ja - Monday, July 24, 2017 - link
This was an interesting read. Thank you!Marnox - Monday, July 24, 2017 - link
According to Intel (https://ark.intel.com/products/97129/Intel-Core-i7... the Turbo speed for the 7700K is the same as the 7740X.mapesdhs - Monday, July 24, 2017 - link
Is the Max Turbo for one core or two? Always bugged me that Intel doesn't list the individual core/bin levels.versesuvius - Monday, July 24, 2017 - link
It will be interesting to see how many of these CPUs Intel will actually produce (collect ?) and bring to the market.