Intel Finalizes Skylake-X Processor Specifications: 18-Cores, 4.4 GHz Turbo, 165W on September 25thby Ian Cutress on August 7, 2017 12:34 PM EST
When Intel launched its new high-end desktop platform a few weeks ago, we were provided with Core-X CPUs from quad cores on the latest Kaby Lake microarchitecture, and 6/8/10 core parts on the Skylake-SP microarchitecture derived from the enterprise line and taking a different route to how the cache was structured over Skylake-S. At the time we were told that these latter parts would be joined by bigger SKUs all the way up to 18 cores, and up to $2000. Aside from core-counts and price, Intel was tight lipped on the CPU specifications until today.
Skylake-X goes HCC
The original Skylake-X processors up to 10 cores used Intel’s LCC silicon, one of the three silicon designs typically employed in the enterprise space, and the lowest core count. The other two silicon designs, HCC and XCC, have historically been reserved for server CPUs and big money – if you wanted all the cores, you had to pay for them. So the fact that Intel is introducing HCC silicon into the consumer desktop market is a change in strategy, which many analysts say is due to AMD’s decision to bring their 16-core silicon into the market.
Both the new HCC-based processors and the recently released LCC-based processors will share the same LGA2066 socket as used on X299 motherboards, and all the processors will differ in core count, with slight variations on core frequencies, TDP and price.
The Skylake-X line-up now looks like:
|Cores / Threads||6/12||8/16||10/20||12/24||14/28||16/32||18/36|
|Base Clock / GHz||3.5||3.6||3.3||2.9||3.1||2.8||2.6|
|Turbo Clock / GHz||4.0||4.3||4.3||4.3||4.3||4.3||4.2|
|L3||1.375 MB/core||1.375 MB/core|
|Memory Freq DDR4||2400||2666||2666|
Along with this, we have several release dates to mention.
- The 12-core Core i9-7920X will be available from August 28th
- The 14-18 core parts will be available from September 25th (my birthday…)
On the specification side, the higher-end CPUs get a kick up in TDP to 165W to account for more cores and the frequency that these CPUs are running at. The top Core i9-7980XE SKU will have a base frequency of 2.6 GHz but a turbo of 4.2 GHz, and a Favored Core of 4.4 GHz. The turbo will be limited to 2 cores of load, however Intel has not listed the ‘all-core turbo’ frequencies which are often above the base frequencies, nor the AVX frequencies here. It will be interesting to see how much power the top SKU will draw.
One question over the launch of these SKUs was regarding how much they would impinge into Intel’s Xeon line of processors. We had already earmarked the Xeon Gold 6154/6150 as possible contenders for the high-end CPU, and taking the price out of the comparison, they can be quite evenly matched (the Xeons have a lower turbo, but higher base frequency). The Xeons also come with multi-socket support and more DRAM channels, at +60% the cost.
Comparing against AMD’s Threadripper gives the following:
|Cores/Threads||18 / 36||16 / 32||16 / 32|
|Base/Turbo||2.6 / 4.2 / 4.4||2.8 / 4.2 / 4.4||3.4 / 4.0|
|GPU PCIe 3.0||44||44||60|
|L2 Cache||1 MB/core||1 MB/core||512 KB/core|
|L3 Cache||24.75 MB||22.00 MB||32.00 MB|
We fully expect the review embargoes to be on the launch dates for each CPU. Time to start ringing around to see if my sample was lost in the post.
- The Intel Skylake-X Review: Core i9 7900X, i7 7820X and i7 7800X Tested
- The Intel Kaby Lake-X i7 7740X and i5 7640X Review
- The Intel Core i7-7700K (91W) Review
- The Intel Core i5-7600K (91W) Review: The More Amenable Mainstream Performer
- The Intel Core i3-7350K (60W) Review: Almost a Core i7-2600K
Update on 8/8:
Due to some sleuthing, PCGamer managed to obtain turbo frequencies based on per-core loading. I'm surprised Intel doesn't give this data out like candy when the products are announced, but we're glad to have it nonetheless.
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Ian Cutress - Wednesday, August 9, 2017 - link4.2 is 2-core boost, as per the image at the bottom of the piece. All-core is 3.4G.
BOBOSTRUMF - Wednesday, August 9, 2017 - linkUnfortunately for Intel, his greed really shows now. Although core still has about 5-10% more IPC compared to Ryzen, the power consumption per core is about 5-15% higher and with 18 cores this really shows. They had a very competitive tick-tock strategy and now after more than three years they are still stuck in 14nm. If they were smarter and created by now just one fab on 8 or 10 nm for the CPU's with many cores things were more simple for them today. In 8 nm, skylake x would had allowed 18 cores on 3.2-3.6Ghz, and not 2.6 as they are doing now.
So they save 3-4 billions dollars not building a 8nm fab but will lose more than this when enthusiast marked will side with AMD.
Please be smarter in future Intel, Samsung and TSMC already have 8 nm FABS while you...
NeatOman - Thursday, August 10, 2017 - linkIntel's 18c 2.6GHz base clock with a 165 watt TDP vs AMD's 3.4GHz base clock with a 180 watt TDP doesn't look like much of a win, especially with less PCI-E lanes. Especially with new test done comparing the Ryzen R5 1600 vs the i7-7800x and both at stock the Intel chip clearly won, but when both were overclocked (AMD 4.0GHz, Intel 4.7GHz) both running 3200MHz ram they were nearly identical within 1%. Which supports people saying that AMD scales better and has better multi-threading (SMT vs HT).
I'm VERY curious to see the results for Ryzen running on quad channel 3200 memory.
I got the FX-8320 the month it came out for about $180 together with a great motherboard, so it was a no brainer.. kinda lol. Had 4 sticks of 1333MHz ram laying around totaling 8GB and quickly upgraded to 16GB 2400MHz CAS-11 (running at 2133MHz CAS-9) and did some testing. Set it to 1333MHz and matched the old ram, then OCed it to find about a 15%+ difference. I did the same thing with a Q9550 i had before and only found about a 5% gain from 4GB 800MHz CAS-5 to 8GB 1150MHz CAS 5 and made sure that there wasn't any page filing.
Point is! lol, I'll wait until i see a RAM speed wall because i don't want to buy some ram then find out 4000MHz is the sweet spot then feel neutered lol. Also, it looks like Ryzen is massively affected by RAM because of CCX interconnecting the cores. It also seems that Ryzen scales very well in frequency.
Avro Arrow - Thursday, August 10, 2017 - linkIn case nobody has noticed (very slim chance but there's a lot of comments), you have Threadripper listed as having only sixty PCI-Express 3.0 lanes when your own article about it from May says sixty-four which is the correct number. You even have the slide on your site. You might want to correct that because some people might get the wrong idea. I'm sure it's just a typo or something but you know how these things can get.
peevee - Thursday, August 10, 2017 - link7960X and 7980XE make no sense at all. Base clock decrease combined with less than linear scalability of even multi-threaded applications combined will give the same real life performance as 7940X.
3.1 * 14= 43.4
2.8 * 16= 44.8
2.6 * 18= 46.8
Non-linear scalability, 3rd level cache contention, memory bus contention, TDP limit will do the rest. And lower ST performance will seal the deal.
Don't waste your money.
wallysb01 - Friday, August 11, 2017 - linkGuys, base clock rate is really just a worst-case scenario. You see the Turbo boosts by number of active cores, right? For the most part, with good cooling that is, those will be achieved and sustained. Or at the very least its going to be closer to that than to the base clocks. So...
3.8 * 14 = 53.2
3.6 * 16 = 57.6
3.4 * 18 = 61.2
If you already have intel systems, download the Intel power gadget, open up activity monitor and run something that maxes all your cores. You'll probably see that so long as temps aren't going crazy, you'll be running above your base clock rate. Even on my MacBook Pro, I can do this with temps around 98C and clock rates sustaining about .4GHz over my base clock for as long as I cared to let the thing run (about 5 minutes, and maybe 2 minutes in it seem to reach a steady state). It state that the 3-4 core turbo on my 4980HQ is 3.6, but I'm really only able to sustain 3.2. This is a laptop though...
eachus - Sunday, August 20, 2017 - linkBack when AMD came out with the original (Sledgehammer) Opterons there was one feature that didn't show up on any spec sheet, but was known by the people in the trenches who wrote server code. (Or in my case, put in compiler optimizations used by the HPC crowd.) Opterons were predictable. If a given job took thirty minutes to run today, it would be within a minute of that (both wall clock and CPU times) tomorrow. I never had a case where the Opteron code path was not pretty much common to all chips. Yes, occasionally you did have to put in "ifdefs" to distinguish between single chip and multiple chip configurations, but no with and without Hyperthreading, with and without SSE, or the latest feature of the month that marketing said we just HAD to support.
Now with Zen, AMD is getting back to that part of their roots. Zen code runs on all Zen chips. Yes, I am writing code that determines how many chips, cores, and threads are present, but that's about it.
Oh, while I am grousing in Intel's general direction, why do they need three subsets of AVX-512. Yes, that is subset, no current processor supports all of AVX-512, and no future processor is expected to do so....
SloppySlim - Wednesday, August 23, 2017 - linkand still no FPGAs ?