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The Intel Skylake-X Review: Core i9-7900X, i7-7820X and i7-7800X Tested
- gbrown_ 9y agoNice to see a breakdown of the myriad of AVX-512 instruction sets. This isn't something Intel was saying much about prior to official launches.
- dogma1138 9y agoThis is something Intel has said for over 2 years now, AVX512 has several instruction sets under it. CD is probably the biggest gamechanger since it now allows you to vectorize code that you couldn't before due to memory conflicts that arise from identical elements in the array. But the difference between Skylake-EP/X and XeonPhi in relation to AVX-512 support were known way in advance.
- gbrown_ 9y ago> But the difference between Skylake-EP/X and XeonPhi in relation to AVX-512 support were known way in advance. I don't think differences in specific instructions were known in advanced, at least at/ shortly after KNL launch. Or rather I was instructed not to mention it.
- dogma1138 9y agohttps://en.wikipedia.org/wiki/AVX-512#New_instructions_in_AVX-512_foundation https://en.wikipedia.org/wiki/AVX-512#New_instructions_in_AV... The instruction set info on that page is 2-3 years old, nothing has changed since then. I've seen those tables at least a year before the KL launch they were also available on Intel's webiste (the blog irrc) at least a year before KL. I don't know who told you that that information is embargoed. EDIT: The inital table was here: http://software.intel.com/en-us/blogs/2013/avx-512-instructions http://software.intel.com/en-us/blogs/2013/avx-512-instructi... the blog post no longer exists, try archive.is https://software.intel.com/en-us/articles/performance-tools-for-software-developers-intel-compiler-options-for-sse-generation-and-processor-specific-optimizations https://software.intel.com/en-us/articles/performance-tools-... "The instruction groups common to both the Intel Xeon Phi processor x200 and the Intel Xeon processor are AVX-512F and AVX-512CD. The AVX-512ER and AVX-512PF groups are implemented in the Intel Xeon Phi processor x200 only. The AVX-512BW, AVX-512DQ and AVX-512VL groups are implemented only in the Intel Xeon processor." https://software.intel.com/en-us/blogs/additional-avx-512-instructions https://software.intel.com/en-us/blogs/additional-avx-512-in... This used to lead to a PDF with the tables, the PDF is still there but it's a living document which is updated every time, the latest revision was in 2017 but as early as 2014 there was already a split into COMMON-AVX512, MIC-AVX512, CORE-AVX512 with a difference between future Xeon Phi and Xeon processors.
- Symmetry 9y agoAll those differences can't be good for adoption.
- Retric 9y agoThose Base/Turbo numbers seem off 3.6 / 4.0 GHz (6 core) 3.3 / 4.3 GHz (8 core) while they both are 140W parts. ED: looks like it's missing the favored core mode which is probably important for gaming. Which brings up an interesting question if CPU's are now going to last ~5 years, is buying a 500+$ CPU reasonable?
- jsheard 9y agoIntel treats TDP numbers as more of a vague classification than an actual indication of power consumption. "140W" is basically code for "tons of power". In PCPerspectives i9-7900X review you can see it uses significantly more power than the i7-6950X despite them both ostensibly being 140W parts. https://www.pcper.com/reviews/Processors/Intel-Core-i9-7900X-10-core-Skylake-X-Processor-Review/Power-Perf-Dollar-Conclusi https://www.pcper.com/reviews/Processors/Intel-Core-i9-7900X...
- dogma1138 9y agoNo, Intel classifies TDP as the instantaneous maximum power draw, AMD classifies it as the average maximum draw over a period of 1M.
- sp332 9y agoBut jsheard's link shows multiple chips using way over the listed TDP. Here's a whitepaper from Intel that explains what it means (as of 2011) [PDF] https://www.intel.com/content/dam/doc/white-paper/resources-xeon-measuring-processor-power-paper.pdf https://www.intel.com/content/dam/doc/white-paper/resources-... Thermal Design Power (TDP) should be used for processor thermal solution design targets. TDP is not the maximum power that the processor can dissipate. TDP is measured at maximum TCASE. TCASE is the temperature measured on the heat spreader over the CPU.
- Analemma_ 9y ago> No, Intel classifies TDP as the instantaneous maximum power draw Are you sure about that? I can't dig up the link at the moment, but I seem to recall some hardware hacker thread where people would regularly exceed the TDP of Intel chips by running SSE/AVX-heavy workloads like Prime95, and Intel's response was basically, "That's not a real workload, it doesn't count". Which is not an unreasonable answer, but it's definitely not defining TDP as the maximum possible power draw.
- bhauer 9y agoThe 7740X retaining dominance in browser-oriented tests demonstrates the continued bottleneck we suffer due to the "single-threaded" (or nominally single-threaded) predilection of web browsers, the DOM, and JavaScript. Servo and other concurrency-oriented innovations are going to be very welcome when they arrive in earnest.
- mtgx 9y agoDoes Mozilla plan to implement that part of Servo through Project Quantum, or not right now?
- masklinn 9y agoI guess, Quantum CSS is the integration of Stylo (parallelised CSS system) into Firefox.
- the8472 9y agoand webrender too. webrender is already available in nightly as experimental option while they're still working on integrating stylo. https://github.com/servo/webrender/wiki https://github.com/servo/webrender/wiki
- masklinn 9y agoWebRender is a GPU renderer though, I don't think it makes much use of on-CPU parallelisation.
- guelo 9y agoServo is a layout engine but the benchmarks are mostly testing javascript performance. Extra cpu cores are not going to speed up JS benchmarks, not because JS is single-threaded but because the benchmarks themselves have to be designed to test multiple threads. The same would be true if the benchmarks were written in C, if you want to test multithreading you have to write code to do it. Javascript benchmarks could test multithreading via Web Workers but for whatever reasons they don't seem to.
- drzaiusapelord 9y agoLooks like we're back to P4-style levels of power use. Not sure how I feel about consumer chips running 150 watts on the regular. That's a lot more carbon in the atmosphere for questionable reasons. https://www.pcper.com/reviews/Processors/Intel-Core-i9-7900X-10-core-Skylake-X-Processor-Review/Power-Perf-Dollar-Conclusi https://www.pcper.com/reviews/Processors/Intel-Core-i9-7900X... Incredibly, the 7900X is hitting 240 watts. When was the last time we had a chip that burned that much energy? Granted, its destined for the server room, but a 2U quad CPU box will be hitting 1000 watts on CPU usage alone at 100% utilization. That's close to a medium-sized window AC unit.
- dogma1138 9y agoIntel has changed the voltage regulation this time its back on the CPU. Skylark-EP gets nowhere near those power draw levels even at similar clocks I have a strong suspension that this is a BIOS issue and the CPU voltage regulator is running full steam (this is equivalent of locking the phase frequency of your VRMs on the motherboard to the max).
- BuckRogers 9y agoYes, those TDPs made them dead on arrival for me. I moved to mini-ITX for my main system and won't be going back. There's no room in my case for any watercooling hardware. I run a Ryzen 7 1700 which is a 65W TDP 8 core, 16 thread CPU. I was going to hold off for Intel's response, but I knew they wouldn't have anything with 8 cores that was anywhere near 65W TDP. CoffeeLake should offer lower TDPs, but with 6 cores max which seems unappealing compared to 8C. I'm going to revisit Intel after they've had time to prepare a real response to Ryzen in ~2020 or so.
- satai 9y agoAny idea, why is Intel so much better at Chrome compilation?
- Synaesthesia 9y agoThe compilers are probably better optimized for the Intel chips.
- deleted 9y ago[deleted]
- Symmetry 9y agoThe number of threads doesn't seem to make much of a difference so I'd guess it's a matter of bandwidth? That seems weird though.
- tormeh 9y agoWell, if you look at the power consumption and the price, they really aren't. The article compares Ryzen processors against Intel's high-core offerings, which makes sense in some ways but not in others.
- gsnedders 9y agoI'm surprised to see that. See for comparison: https://www.phoronix.com/scan.php?page=article&item=ryzen-1800x-linux&num=5 https://www.phoronix.com/scan.php?page=article&item=ryzen-18... has the Ryzen 7 1800X beating even the i7 5960X when compiling the Linux kernel. http://www.hardware.fr/articles/956-13/compilation-visual-studio-mingw-w64-gcc.html http://www.hardware.fr/articles/956-13/compilation-visual-st... has the Ryzen 7 1800X drawing around even when compiling Boost (under both MSVC and MinGW gcc, so it isn't just a compiler difference). I wonder if it's linking the huge binaries at the end of the compile that makes all the difference, especially with the difference in L3 caches? I'd be surprised if the individual compile units were that much larger as to make a difference.
- IanCutress 9y agoThe chrome compile test doesn't like L3 victim caches. Ryzen does badly as a result. Clock for Clock the Skylake-SP cores do bad as well, but Skylake-X is well clocked with cores, so it's still top of the charts.
- vosper 9y agoIn the meantime, the 6 core Broadwell-E I7-6850K has seen a big price drop - down from $650 to $480 on several sites. It's still expensive compared to the Kaby Lake I7-7700K, but if you wanted two more cores then it's now a much more reasonable option. People seem to have very good results overclocking it, too. Edit: Having just seen that the i7-7800X is priced at $389, I'm thinking the I7-6850K is still overpriced, unless you need 40 PCI-E lanes.
- jhasse 9y agoWhy not go with a Ryzen 7 1700 instead if you want more cores?
- icelancer 9y agoI looked into this and was going to buy a Ryzen or wait for the Threadripper for a huge multicore video transcoding server we run, in an attempt to source parts for an upgrade for our last-gen i7 platform. Unfortunately Ryzen's performance in ffmpeg is dismal, relating to its poor AVX performance, it seems. I've seen comments on their platform being "poor" due to software not tuning for the platform specifically, which is definitely possible. But unfortunately I can't bank on that for now, so we had to stay with Intel for our batch transcoding processes. Still very excited to monitor this product line; it's been a long time coming. https://www.phoronix.com/scan.php?page=article&item=ryzen-1800x-linux&num=5 https://www.phoronix.com/scan.php?page=article&item=ryzen-18... http://www.pcgamer.com/the-amd-ryzen-7-review/4/ http://www.pcgamer.com/the-amd-ryzen-7-review/4/
- problems 9y agoCurious - why are you doing video transcoding on CPUs? The CPU to GPU speedup is so massive that it's really not worth it. I don't recall the exact numbers, but I got an order of magnitude boost going from HEVC encoding on CPU to GPU with no noticeable quality difference. Works out to several times more efficient too FPS/watt wise.
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- bratao 9y agoI´m surprised to see how the AMD Ryzen are still holding on the benchmarks
- noir_lord 9y agoI've got a Ryzen 1700 I built for work, it's so good I'm shifting up my upgrade at home to back of this year and looking hard at the 1700X. It's just fantastic at the price point.
- bratao 9y agoYeah, it is. I also build a Ryzen 1700 in a 2U case and for my workload (6 Virtualbox Machines) it is just amazing
- HNaTTY 9y agoMy 1700x build for video processing has suffered major instabilities -- app crashes and BSODs -- memory corruption type errors. I went through 4 different types of DDR4 memory until I found some that works, even though it isn't on the ASUS's Qualified Vendors List. My advice is to make sure your RAM can do 15-15-15-36 timings (or better).
- noir_lord 9y agoI ran all the usual suspects (memtest86 etc) for 24 hours after I built it, not had a single issue in 2 weeks under Linux (Fedora 25) though I've seen people having a lot of issues with various RAM configurations. I went for 32GB of Corsair Vengeance over 2x16GB at a conservative timing (the newer beta bios for the mobo I have supports more memory options as was as clocking) since it's a machine at work.
- icelancer 9y agoI've also heard the same. I've made comments on this post about the issues and poor performance with transcoding (specifically ffmpeg benchmarks), which is unfortunately why I've had to stay away.
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- jjawssd 9y agoBrowsers that take advantage of multiple cores more effectively will accelerate the rate at which Intel circles the drain in consumer applications. EDIT: why the downvotes? explain yourselves
- wmf 9y agoIntel isn't really circling the drain and their future woes are more likely to be caused by overall shrinking of the PC market, not by loss of market share to slower chips. As good as Ryzen is, it will probably only increase AMD's market share from 5% to 10% due to inertia and such. Speaking of browsers, they aren't really a good benchmark for 6-10 core processors since anything is going to be fast enough. Also, existing JS can't really be parallelized so I suspect even a magical browser would still benefit from single-thread performance.
- ryao 9y agoIt might be possible to do auto parallelization in some cases like what GCC can do: https://gcc.gnu.org/wiki/AutoParInGCC https://gcc.gnu.org/wiki/AutoParInGCC Still, it might be even better if people would stop writing such JavaScript intensive websites. They are not very friendly to blind internet users.
- jshevek 9y agoI've enjoyed some comments you've made elsewhere, and don't want you to run afoul of HN rules and culture. I believe that discussing the fact of the downvotes is strongly discouraged on HN.
- knorker 9y agoWow. From multiple sites releasing reviews it's clear that an embargo was just lifted. And anandtech couldn't bother writing a proper article? Sentence after sentence just hard to read, with extra commas and just poor sentence structures. Did they not have time during the embargo?
- Symmetry 9y agoI'm surprised at how well Ryzen is holding up in FP terms despite the relative lack of flops on paper. I guess having a separate floating point cluster is enough of an advantage to make up for that? It really makes me want to see how it works with robot motion planning at work.
- faragon 9y agoTL;DR: Intel is having hard time to keep up against AMD. It reminds me the Pentium 4 era, when Intel had to push clock and power consumption to crazy levels [1] [1] http://www.anandtech.com/show/11550/the-intel-skylakex-review-core-i9-7900x-i7-7820x-and-i7-7800x-tested/8 http://www.anandtech.com/show/11550/the-intel-skylakex-revie...
- soulnothing 9y agoThe[1] biggest take away to me in the review. The AMD at 95W was within striking distance of the 140W Intel part. Then a 65W snuck above a 140W part. Yes TDP is measured differently, etc. But still interesting. [1] http://images.anandtech.com/graphs/graph11550/87127.png http://images.anandtech.com/graphs/graph11550/87127.png
- paulmd 9y agoIt's a pretty natural consequence of how much crap Intel piled in on this release. Cache, mesh, and AVX512 all consume a great deal of power. Contrary to what the sibling comment says, Ryzen is nowhere near Intel's performance here. Even in very parallel tasks like x264 video encoding, the 7800K (6-cores) is beating the highest-clocked 8C Ryzens by almost 6%. Comparing apples to apples, the 7820X (8C) is 33% faster than the 1800X. That's a very good place for Intel to be overall, even if their power consumption is higher than I'd like to see. Downclocked Xeons will probably beat Ryzen's efficiency. And there may be some UEFI/microcode gains to be made here as well, both in efficiency and total performance. The bigger problem (for the enthusiast market) is the thermals. Intel just switched from solder to TIM on the HEDT processors and it's very clear that they cannot move heat out of the package fast enough and it's limiting the total OC, which would likely reach 5 GHz a good chunk of the time. http://i.imgur.com/9e8Trr3.png http://i.imgur.com/9e8Trr3.png
- faragon 9y ago33% faster encoding x264, at what price? Ryzen 7 1800X: $499, Core i7-7820X: $599 (+20% over Ryzen). You can also cherry-pick tests where the Ryzen gets better performance or better performance/price, and not just tests involving AVX usage. Also, in cheaper Ryzen's the performance/price gets abysmal in favor of AMD. BTW, you can compare also a $599 GPU performance encoding x264 versus that Intel CPU and see how "fast" are Intel CPUs in comparison.
- deleted 9y ago[deleted]
- dis-sys 9y agoSaw some test results on Chinese website claiming that once fully loaded the temp can jump to 100+ degrees when running at stock frequency without any form of overclocking. It that true? http://img1.mydrivers.com/img/20170620/0ff9382549894c64a9989e9d578c3e7e.jpg http://img1.mydrivers.com/img/20170620/0ff9382549894c64a9989...
- en4bz 9y agoThese are the first Intel HEDT chips to not have a soldered heat-spreader. Instead they are using thermal paste between the chip and the heat-spreader. This is generally accepted to be bad practice since they use cheap paste and it's dependent on how the paste was spread on each chip. I also believe that Intel has basically said water cooling is a must for these chips.
- dis-sys 9y agowill be interesting to see whether they still have room for overclocking or Intel has already done so. ;)
- dom0 9y agoWell anandtech already found that water cooling is simply insufficient to cool these for overclocking. You need an active thermal sink AKA a compressor cooler, and then you're still limited by the TIM-gunk; heat-spreader at 25 °C, core at 100 °C. I suppose for the next generation Intel will announce that liquid nitrogen is basically required.
- TomMarius 9y agoUsage of liquid nitrogen would put us just a few steps away from achieving superconductivity... Thanks Intel, I guess?
- myrandomcomment 9y agoEh. Going with AMD for my next home system. Power and cooling is the key for a home theater + game system.
- osmala 9y agoi7 7820X is the CPU is probably the best system price/performance overall in the long run right now. Threadripper might be competing it depending on what you do but we don't know about it yet. For software developers having over 50% lead in compilation performance compared to ryzen 7 1800X (nightly build of chromium on visual studio) should make it a good choice. A) In system price there are many components and that makes ultra cheap CPU:s in other vice identical configurations not so good price-performance. B) Performance is really the performance differential from what you upgrade. And even more importantly the performance differential years from now to systems of that time, if you upgrade to a system that lasts 5 years before you upgrade or to a system that lasts 7 years before you upgrade is significant in terms of price/performance because later means you get the high performance early and price last longer. C) Significantly higher single threaded performance compared to Ryzen 7 the main contender. There are still many tasks that are single threaded, especially if you run legacy code. D) AVX-512 I doubt the review benchmarks are in AVX-512 but some legacy code. AVX-512 increases both width of vector and fraction of code and algorithms that can be parallerized significantly. Once compilers are well tuned to use AVX-512 the code compiled with AVX-512 optimizations turned on should be significantly faster than what it was before hand. Simply being able to do 8-16 times work per cycle in large variety of tasks is significant advantage even if that is for a good fraction of time instead of all the time. Personally I7-920 has given me far better price-performance compared to people who bought dual core at the time simply because it has lasted LONGER so it had superior price/(time between CPU upgrades) measurement. Right now in that same measurement I7-7820X is the king. So in conclusion I7-7820X is faster in both real legacy code and the future code, and gives good enough performance longer simply because code that you run when you would start considering upgrades run much faster on it simply because of extensions.
- ryao 9y agoWhy is a 6-core Intel processor beating the more expensive 8-core Ryzen at video encoding?
- dom0 9y agoHigher clocks, much larger thermal envelope, twice as many memory channels, ...