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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extide - Tuesday, July 11, 2017 - link
PCPer made this same mistake -- Nehalem/Westmere used a crossbar memory bus -- not a ringbus. Only Nehalem/Westmere EX used the ringbus (the 6500/7500 series) The i7 and Xeon 5500 and 5600 series used the crossbar.extide - Tuesday, July 11, 2017 - link
Sandy Bridge brought the ringbus down to Xeon EP and client chips.Yorgos - Tuesday, July 11, 2017 - link
"With the complexity of both server hardware and especially server software, that is very little time. There is still a lot to test and tune, but the general picture is clear."No wonder why we see ubuntu and ancient versions of gcc and the rest of the s/w stack.
Imagine if you tried to use debian or rhel, it would take you decades to get the review.
eligrey - Tuesday, July 11, 2017 - link
Why did you omit the Turbo frequencies for the Xeon Gold 6146 and 6144?Intel ARK says that the 6146's turbo frequency is 4.2GHz and the 6144's is 4.5GHz.
eligrey - Tuesday, July 11, 2017 - link
Oops, I mean 4.2GHz for both.boozed - Tuesday, July 11, 2017 - link
Need more Skylake-SP SKUsrHardware - Tuesday, July 11, 2017 - link
For the purley system, It's listed that you used Chipset Intel Wellsburg B0This information cannot be correct. Lewisburg Chipset is the name of the purley chipset. Also, B0 stepping lewisburg also wouldn't boot with the stepping of CPU you have.
rHardware - Tuesday, July 11, 2017 - link
That 0200011 microcode is also very old.Rickyxds - Tuesday, July 11, 2017 - link
I'am a brazilian processors enthusiast and I'am very critic about intel and AMD processors, between 2012 and Q1 2017 AMD just doesn't existed, who bought AMD on that years, bougth just for love AMD and just it, doesn't for the price, doesn't for the high core count, doesn't for AMD is red, AMD was the worst performance processors. The A9 Apple dual core performance is better than FX 8150.But now I am very surprise with the aggressive AMD prices. No one here Imagined get the Ryzen 7 performance for less than $500. And I don't know if this scenario brings profit to AMD, but for the image against the intel it's wonderful.
On the next years we will see.
krumme - Tuesday, July 11, 2017 - link
Thank you for quality stuff article especially given the short time. So thank you for booting up Johan !Interesting and surpricing results.