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.
Facebook
Twitter
RSS
176 Comments
View All Comments
Santoval - Tuesday, July 25, 2017 - link
That is not how IPC works, since it explicitly refers to single core - single thread performance. As the number of cores rises the performance of a *single* task never scales linearly because there is always some single thread code involved (Amdahl's law). For example if your task has 90% parallel and 10% serial code its performance will max out at x10 that of a single core at ~512 cores. From then on even if you had a CPU with infinite cores you couldn't extract half an ounce of additional performance. If your code was 95% parallel the performance of your task would plateau at x20. For that though you would need ~2048 cores. And so on.Of course Amdahl's law does not provide a complete picture. It assumes, for example, that your task and its code will remain fixed no matter how many cores you add on them. And it disregards the possibility of computing distinct tasks in parallel on separate cores. That's where Gustafson's Law comes in. This "law" is not concerned with speeding up the performance of tasks but computing larger and more complex tasks at the same amount of time.
An example given in Wikipedia involves boot times : Amdahl's law states that you can speed up the boot process, assuming it can be made largely parallel, up to a certain number of cores. Beyond that -when you become limited by the serial code of your bootloader- adding more cores does not help. Gustafson's law, on the contrary, states that instead of speeding up the boot process by adding more cores and computing resources, you could add colorful GUIs, increase the resolution etc, while keeping the boot time largely the same. This idea could be applied to many -but not all- computing tasks, for example ray tracing (for more photorealistic renderings) and video encoding (for smaller files or videos with better quality), and many other heavily multi-threaded tasks.
Rickyxds - Monday, July 24, 2017 - link
I just agree XD.Diji1 - Wednesday, July 26, 2017 - link
"Overall speed increase 240%."LMAO. Ridiculous.
Alistair - Wednesday, July 26, 2017 - link
No reason to laugh. I compared the 6600k vs the Ryzen 1700. 1 year speed increase of 144 percent (2.44 times the speed). Same as this: 1135 vs 466 points.http://cpu.userbenchmark.com/Compare/Intel-Core-i5...
Dr. Swag - Tuesday, July 25, 2017 - link
I disagree, best value is 1600 as it oces as well as 1600x, comes with a decent stock cooler, and is cheaper.vext - Monday, July 24, 2017 - link
Interesting article but it seems intended to play down the extremely bad press x299 has received which is all over the internet and Youtube.Once you get past Mr. Cuttress' glowing review, it's clear that the I5-7640x is not worth the money because of lackluster performance, the I7-7740X is marginally faster than the older 7700k, and the I7-7800x is regularly beaten by the 7740X in many benchmarks that actually count and is a monstrously inefficient energy pig. Therefore the only Intel CPUs of this batch worth buying are the 7700k/7740x, and there is no real advantage to x299. In summary, it doesn't actually change anything.
It's very telling that Mr. Cutress doesn't comment on the absolutely egregious energy consumption of the 7800x. The Test Bed setup section doesn't list the 7800x at all. The 7840x and 7740x are using a Thermalright True Copper (great choice!) but no info on the 7800x cooler. Essentially, the 7800x cameo appearance is only to challenge the extremely strong Ryzen multi-threaded results, but its negative aspects are not discussed, perhaps because it might frighten people from x299. Tsk, tsk. As my 11 year old daughter would say "No Fair." By the way, the 7800x is selling for ~ $1060 right now on Newegg, not $389.
Proudly typed on my Ryzen 1800x/Gigabyte AB350 Gaming 3. # ;-)
Ian Cutress - Monday, July 24, 2017 - link
You may not have realised but this is the Kaby Lake-X review, so it focuses on the KBL-X parts. We already have a Skylake-X review for you to mull over. There are links on the first page.mapesdhs - Monday, July 24, 2017 - link
Nevertheless, the wider picture is relevant here. The X299 platform is a mess. Intel is aiming KL-X at a market which doesn't exist, they've locked out features that actually make it useful, it's more power hungry, and a consumer needs a lot of patience and plenty of coffee to work out what the heck works and what doesn't on a mbd with a KL-X fitted.This is *exactly* the sort of criticism of Intel which should have been much stronger in the tech journalism space when Intel started pulling these sorts of stunts back with the core-crippled 3930K, heat-crazy IB and PCIe-crippled 5820K. Instead, except for a few exceptions, the tech world has been way too forgiving of Intel's treading-on-water attitude ever since SB, and now they've panicked in response to Ryzen and released a total hodgebodge of a chipset and CPU lineup which makes no sense at all. And if you get any disagreement about what I've said by anyone at Intel, just wave a 4820K in their face and say well explain this then (quad-core chip with 40 PCIe lanes, da daa!).
I've been a big fan of Z68 and X79, but nothing about Intel's current lineup appeals in the slightest.
serendip - Tuesday, July 25, 2017 - link
There's also the funny bit about motherboards potentially killing KBL-X CPUs if a Skylake-X was used previously.What's with Intel's insane product segmentation strategy with all the crippling and inconsistent motherboard choices? It's like they want to make it hard to choose, so buyers either get the cheapest or most expensive chip.
Haawser - Tuesday, July 25, 2017 - link
'EmergencyLake-X' is just generally embarrassing. Intel should just find a nearby landfill site and quietly bury it.