Sizing Up Servers: Intel's Skylake-SP Xeon versus AMD's EPYC 7000 - The Server CPU Battle of the Decade?
by Johan De Gelas & Ian Cutress on July 11, 2017 12:15 PM EST- Posted in
- CPUs
- AMD
- Intel
- Xeon
- Enterprise
- Skylake
- Zen
- Naples
- Skylake-SP
- EPYC
Intel's Optimized Turbo Profiles
Also new to Skylake-SP, Intel has also further enhanced turbo boosting.
There are also some security and virtualization enhancements (MBE, PPK, MPX) , but these are beyond the scope this article as we don't test them.
Summing It All Up: How Skylake-SP and Zen Compare
The table below shows you the differences in a nutshell.
| AMD EPYC 7000 |
Intel Skylake-SP | Intel Broadwell-EP |
|
| Package & Dies | Four dies in one MCM | Monolithic | Monolithic |
| Die size | 4x 195 mm² | 677 mm² | 456 mm² |
| On-Chip Topology | Infinity Fabric (1-Hop Max) |
Mesh | Dual Ring |
| Socket configuration | 1-2S | 1-8S ("Platinum") | 1-2S |
| Interconnect (Max.) Bandwidth (*)(Max.) |
4x16 (64) PCIe lanes 4x 37.9 GB/s |
3x UPI 20 lanes 3x 41.6 GB/s |
2x QPI 20 lanes 2x 38.4 GB/s |
| TDP | 120-180W | 70-205W | 55-145W |
| 8-32 | 4-28 | 4-22 | |
| LLC (max.) | 64MB (8x8 MB) | 38.5 MB | 55 MB |
| Max. Memory | 2 TB | 1.5 TB | 1.5 TB |
| Memory subsystem Fastest sup. DRAM |
8 channels DDR4-2666 |
6 channels DDR4-2666 |
4 channels DDR4-2400 |
| PCIe Per CPU in a 2P |
64 PCIe (available) | 48 PCIe 3.0 | 40 PCIe 3.0 |
(*) total bandwidth (bidirectional)
At a high level, I would argue that Intel has the most advanced multi-core topology, as they're capable of integrating up to 28 cores in a mesh. The mesh topology will allow Intel to add more cores in future generations while scaling consistently in most applications. The last level cache has a decent latency and can accommodate applications with a massive memory footprint. The latency difference between accessing a local L3-cache chunk and one further away is negligible on average, allowing the L3-cache to be a central storage for fast data synchronization between the L2-caches. However, the highest performing Xeons are huge, and thus expensive to manufacture.
AMD's MCM approach is much cheaper to manufacture. Peak memory bandwidth and capacity is quite a bit higher with 4 dies and 2 memory channels per die. However, there is no central last level cache that can perform low latency data coordination between the L2-caches of the different cores (except inside one CCX). The eight 8 MB L3-caches acts like - relatively low latency - spill over caches for the 32 L2-caches on one chip.
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Shankar1962 - Wednesday, July 12, 2017 - link
AMD is fooling everyone one by showing more cores, pci lanes, security etcCan someone explain me why GOOGLE ATT AWS ALIBABA etc upgraded to sky lake when AMD IS SUPERIOR FOR HALF THE PRICE?
Shankar1962 - Wednesday, July 12, 2017 - link
Sorry its BaiduPretty sure Alibaba will upgrade
https://www.google.com/amp/s/seekingalpha.com/amp/...
PixyMisa - Thursday, July 13, 2017 - link
Lots of reasons.1. Epyc is brand new. You can bet that every major server customer has it in testing, but it could easily be a year before they're ready to deploy.
2. Functions like ESXi hot migration may not be supported on Epyc yet, and certainly not between Epyc and Intel.
3. Those companies don't pay the same prices we do. Amazon have customised CPUs for AWS - not a different die, but a particular spec that isn't on Intel's product list.
There's no trick here. This is what AMD did before, back in 2006.
blublub - Tuesday, July 11, 2017 - link
I kinda miss Infinity Fabric on my Haswell CPU and it seems to only have on die - so why is that missing on Haswell wehen Ryzen is an exact copy?blublub - Tuesday, July 11, 2017 - link
argh that post did get lost.zappor - Tuesday, July 11, 2017 - link
4.4.0 kernel?! That's not good for single-die Zen and must be even worse for Epyc!AMD's Ryzen Will Really Like A Newer Linux Kernel:
https://www.phoronix.com/scan.php?page=news_item&a...
Kernel 4.10 gives Linux support for AMD Ryzen multithreading:
http://www.pcworld.com/article/3176323/linux/kerne...
JohanAnandtech - Friday, July 21, 2017 - link
We will update to a more updated kernel once the hardware update for 16.04 LTS is available. Should be August according to Ubuntukwalker - Tuesday, July 11, 2017 - link
You mention an OpenFOAM benchmark when talking about the new mesh topology but it wasn't included in the article. Any way you could post that? We are trying to evaluate EPYC vs Skylake for CFD applications.JohanAnandtech - Friday, July 21, 2017 - link
Any suggestion on a good OpenFoam benchmark that is available? Our realworld example is not compatible with the latest OpenFoam versions. Just send me an e-mail, if you can assist.Lolimaster - Tuesday, July 11, 2017 - link
AMD's lego design where basically every CCX can be used in whatever config they want be either consumer/HEDT or server is superior in the multicore era.Cheaper to produce, cheaper to sell, huge profits.