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
AMD’s EPYC 7000-Series Processors
As announced back at the official launch, AMD is planning to hit both the dual socket and single socket markets. With up to 32 cores, 64 threads, 2TB/socket support and 128 PCIe lanes per CPU, they believe that by offering a range of core counts and frequencies, they have the nous to attack Intel, even if it comes at a slight IPC disadvantage.
AMD’s main focus will be on the 2P parts, where each CPU will use 64 PCIe lanes (using the Infinity Fabric protocol) to connect to each other, meaning that in a 2P system there will still be 128 PCIe 3.0 lanes to go around for add-in devices. There will be the top four SKUs available initially, and the other parts should be in the hands of OEMs by the end of July. All the CPUs will have access to all 64MB of the L3 cache, except the 7200-series which will have access to half.
The new processors from AMD are called the EPYC 7000 series, with names such as EPYC 7301 and EPYC 7551P. The naming of the CPUs is as follows:
EPYC 7551P
- EPYC = Brand
- 7 = 7000 Series
- 30/55 = Dual Digit Number indicative of stack positioning / performance (non-linear)
- 1 = Generation
- P = Single Socket, not present in Dual Socket
So in the future, we will see second generation ‘EPYC 7302’ processors, or if AMD scales out the design there may be EPYC 5000 processors with fewer silicon dies inside, or EPYC 3000 with a single die but for the EPYC platform socket (obviously, those last two are speculation).
But starting with the 2P processors:
| AMD EPYC Processors (2P) | |||||||||
| Cores Threads |
Frequency (GHz) | L3 | DRAM | PCIe | TDP | Price | |||
| Base | All | Max | |||||||
| EPYC 7601 | 32 / 64 | 2.20 | 2.70 | 3.2 | 64 MB | 8-Ch DDR4 2666 MT/s |
8 x16 128 PCIe |
180W | $4200 |
| EPYC 7551 | 32 / 64 | 2.00 | 2.55 | 3.0 | 180W | >$3400 | |||
| EPYC 7501 | 32 / 64 | 2.00 | 2.60 | 3.0 | 155W/170W | $3400 | |||
| EPYC 7451 | 24 / 48 | 2.30 | 2.90 | 3.2 | 180W | >$2400 | |||
| EPYC 7401 | 24 / 48 | 2.00 | 2.80 | 3.0 | 155W/170W | $1850 | |||
| EPYC 7351 | 16 / 32 | 2.40 | 2.9 | 155W/170W | >$1100 | ||||
| EPYC 7301 | 16 / 32 | 2.20 | 2.7 | 155W/170W | >$800 | ||||
| EPYC 7281 | 16 / 32 | 2.10 | 2.7 | 32 MB | 155W/170W | $650 | |||
| EPYC 7251 | 8 / 16 | 2.10 | 2.9 | 120W | $475 | ||||
The top part is the EPYC 7601, which is the CPU we were provided for in this comparison. This is a 32-core part with simultaneous multithreading, a TDP of 180W and a tray price of $4200. As the halo part, it also gets the good choice on frequencies: 2.20 GHz base, 3.2 GHz at max turbo (up to 12 cores active) and 2.70 GHz when all cores are active.
Moving down the stack, AMD will offer 24, 16 and 8-core parts. These will disable 1, 2 and 3 cores per CCX respectively, as we saw with the consumer Ryzen processors, and is done in order to keep core-to-core latencies more predictable (as well as keeping access to all the L3 cache). What is interesting to note is that AMD will offer a 32-core part at 155W (when using DDR4-2400) for $3400, which is expected to be very competitive compared to Intel (and support 2.66x more DRAM per CPU).
The 16-core EPYC 7281, while having half the L3, will be available for $650, making an interesting 2P option. Even the bottom processor at the stack, the 8-core EPYC 7251, will support the full 2TB of DRAM per socket as well as 128 PCIe lanes, making it a more memory focused SKU and having almost zero competition on these sorts of builds from Intel. For software that requires a lot of memory but pays license fees per core/socket, this is a nice part.
For single socket systems, AMD will offer the following three processors:
| AMD EPYC Processors (1P) | |||||||||
| Cores Threads |
Frequency (GHz) | L3 | DRAM | PCIe | TDP | Price | |||
| Base | All | Max | |||||||
| EPYC 7551P | 32 / 64 | 2.0 | 2.6 | 3.0 | 64 MB | 8-Ch DDR4 2666 MT/s |
8 x16 128 PCIe |
180W | $2100 |
| EPYC 7401P | 24 / 48 | 2.0 | 2.8 | 3.0 | 155W/170W | $1075 | |||
| EPYC 7351P | 16 / 32 | 2.4 | 2.9 | 155W/170W | $750 | ||||
These processors mirror the specifications of the 2P counterparts, but have a P in the name and slightly different pricing.
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JohanAnandtech - Friday, July 21, 2017 - link
Thanks! It is was a challenge, and we will update this article later on, when better kernel support is available.serendip - Tuesday, July 11, 2017 - link
What idiot marketroid thought it was cool to have a huge list of SKUs and gimped "precious metals" branding? I'd like to see Epyc kicking Xeon butt simply because AMD has much more sensible product lists and there's not much gimping going on.ParanoidFactoid - Tuesday, July 11, 2017 - link
Reading through this, the takeaway seems thus. Epyc has latency concerns in communicating between CCX blocks, though this is true of all NUMA systems. If your application is latency sensitive, you either want a kernel that can dynamically migrate threads to keep them close to their memory channel - with an exposed API so applications can request migration. (Linux could easily do this, good luck convincing MS). OR, you take the hit. OR, you buy a monolithic die Intel solution for much more capital outlay. Further, the takeaway on Intel is, they have the better technology. But their market segmentation strategy is so confusing, and so limiting, it's near impossible to determine best cost/performance for your application. So you wind up spending more than expected anyway. AMD is much more open and clear about what they can and can't do. Intel expects to make their money by obfuscating as part of their marketing strategy. Finally, Intel can go 8 socket, so if you need that - say, high core low latency securities trading - they're the only game in town. Sun, Silicon Graphics, and IBM have all ceded that market.msroadkill612 - Wednesday, July 12, 2017 - link
"it's near impossible to determine best cost/performance for your application. So you wind up spending more than expected anyway. AMD is much more open and clear about what they can and can't do. Intel expects to make their money by obfuscating as part of their marketing strategy.Finally, Intel can go 8 socket, so if you need that - say, high core low latency securities trading - they're the only game in town. Sun, Silicon Graphics, and IBM have all ceded that market."
& given time is money, & intelwastes customers time, then intel is expensive.
Those guys will go intel anyway, but just sayin, there is already talk of a 48 core zen cpu, making 98 cores on a mere 2p mobo.
As i have posted b4, if wall street starts liking gpu compute for prompter answers, amdS monster apuS will be unanswerable.
nils_ - Wednesday, July 19, 2017 - link
98 cores on a 2p mobo isn't quite right if you keep in mind that the 32 core versions already constitute a 4 CPU system, unless AMD somehow manages to get more cores on a single die.nils_ - Wednesday, July 19, 2017 - link
Good analysis, although Sun and IBM are still coming out with new CPUs and at least with IBM there is renewed interest in the POWER ecosystem.eek2121 - Wednesday, July 12, 2017 - link
, but rather AMD's spanking new EPYC server CPU. Both CPUs are without a doubt very different: micro architecture, ISA extentions, <snip>Should be extensions.
intelemployee2012 - Wednesday, July 12, 2017 - link
After looking at the number of people who really do not fully understand the entire architecture and workloads and thinking that AMD Naples is superior because it has more cores, pci lanes etc is surprising.AMD made a 32 core server by gluing four 8core desktop dies whereas Intel has a single die balanced datacenter specific architecture which offers more perf if you make the entire Rack comparison. It's not the no of cores its the entire Rack which matters.
Intel cores are superior than AMD so a 28 core xeon is equal to ~40 cores if you compare again Ryzen core so this whole 28core vs 32core is a marketing trick. Everyone thinks Intel is expensive but if you go by performance per dollar Intel has a cheaper option at every price point to match Naples without compromising perf/dollar.
To be honest with so many Fabs, don't you think Intel is capable of gluing desktop dies to create a 32core,64core or evn 128core server (if it wants to) if thats the implementation style it needs to adopt like AMD?
The problem these days is layman looks at just numbers but that's not how you compare.
sharath.naik - Wednesday, July 12, 2017 - link
Agree, Most who look at these numbers will walk away thinking AMD is doing well with EPYC. The article points out the approach to testing and also states the performance challenges with EPYC, which can be missed who reading this review without the prior review on the older Xeons. For example the Big data test, I bet the newbies will walk away thinking EPYC beats the older XEONS E5 v4, as thats what the graphs show,without ever looking back at the numbers for a single 22 core Xeon e5 v4. So yes, a few back links in the article will be helpful.warreo - Wednesday, July 12, 2017 - link
Not a fanboi of either company, but care to elaborate more? I checked the original Xeon E5 v4 review. It shows that a single Xeon E5 v4 performs about 10% slower than a dual setup. Extrapolating that here, that means the single Xeon E5 v4 setup would be right around 4.5 jobs per day, which would make it roughly 50% slower than the dual Epyc and Xeon 8176.Sure, you could argue perf/dollar is better against a dual Epyc setup...but one could make the same argument against Intel's Skylake Xeons? I also wouldn't expect the performance to scale linearly anyway. Please let me know what I'm missing.