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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ddriver - Wednesday, July 12, 2017 - link
LOL, buthurt intel fanboy claims that the only unbiased benchmark in the review is THE MOST biased benchmark in the review, the one that was done entirely for the puprpose to help intel save face.Because if many core servers running 128 gigs of ram are primarily used to run 16 megabyte databases in the real world. That's right!
Beany2013 - Tuesday, July 11, 2017 - link
Sure, test against Ubuntu 17.04 if you only plan to have your server running till January. When it goes end of life. That's not a joke - non LTS Ubuntu released get nine months patches and that's it.https://wiki.ubuntu.com/Releases
16.04 is supported till 2021, it's what will be used in production by people who actually *buy* and *use* servers and as such it's a perfectly representative benchmark for people like me who are looking at dropping six figures on this level of hardware soon and want to see how it performs on...goodness, realistic workloads.
rahvin - Wednesday, July 12, 2017 - link
This is a silly argument. No one running these is going to be running bleeding edge software, compiling special kernels or putting optimizing compiler flags on anything. Enterprise runs on stable verified software and OS's. Your typical Enterprise Linux install is similar to RHEL 6 or 7 or it's variants (some are still running RHEL 5 with a 2.6 kernel!). Both RHEL6 and 7 have kernels that are 5+ years old and if you go with 6 it's closer to 10 year old.Enterprises don't run bleeding edge software or compile with aggressive flags, these things create regressions and difficult to trace bugs that cost time and lots of money. Your average enterprise is going to care about one thing, that's performance/watt running something like a LAMP stack or database on a standard vanilla distribution like RHEL. Any large enterprise is going to take a review like this and use it as data point when they buy a server and put a standard image on it and test their own workloads perf/watt.
Some of the enterprises who are more fault tolerant might run something as bleeding edge as an Ubuntu Server LTS release. This review is a fair review for the expected audience, yes every writer has a little bias but I'd dare you to find it in this article, because the fanboi's on both sides are complaining that indicates how fair the review is.
jjj - Tuesday, July 11, 2017 - link
Do remember that the future is chiplets, even for Intel.The 2 are approaching that a bit differently as AMD had more cost constrains so they went with a 4 cores CCX that can be reused in many different prods.
Highly doubt that AMD ever goes back to a very large die and it's not like Intel could do a monolithic 48 cores on 10nm this year or even next year and that would be even harder in a competitive market. Sure if they had a Cortex A75 like core and a lot less cache, that's another matter but they are so far behind in perf/mm2 that it's hard to even imagine that they can ever be that efficient.
coder543 - Tuesday, July 11, 2017 - link
Never heard the term "chiplet" before. I think AMD has adequately demonstrated the advantages (much higher yield -> lower cost, more than adequate performance), but I haven't heard Intel ever announce that they're planning to do this approach. After the embarrassment that they're experiencing now, maybe they will.Ian Cutress - Tuesday, July 11, 2017 - link
Look up Intel's EMIB. It's an obvious future for that route to take as process nodes get smaller.Threska - Saturday, July 22, 2017 - link
We may see their interposer (like used with their GPUs) technology being used.jeffsci - Tuesday, July 11, 2017 - link
Benchmarking NAMD with pre-compiled binaries is pretty silly. If you can't figure out how to compile it for each every processor of interest, you shouldn't be benchmarking it.CajunArson - Tuesday, July 11, 2017 - link
On top of all that, they couldn't even be bothered to download and install a (completely free) vanilla version that was released this year. Their version of NAMD 2.10 is from *2014*!http://www.ks.uiuc.edu/Development/Download/downlo...
tamalero - Tuesday, July 11, 2017 - link
Do high level servers update their versions constantly?I know that most of the critical stuff, only patch serious vulnerabilities and not update constantly to newer things just because they are available.