AMD Rome Second Generation EPYC Review: 2x 64-core Benchmarked

Rome CPUs: Core Counts and Frequencies

There has been little doubt that on paper Rome and the EPYC 7002 family will be a competitive product compared to Intel's Xeon Scalable when it comes to performance or performance per watt. As always, it comes down to paring which part offers the right competition. With Rome, AMD is once again attacking performance per dollar, as well as peak performance and performance per watt. 

EPYC 7000 nomenclature

The naming of the CPUs is kept consistent with the previous generation.

• EPYC = Brand
• 7 = 7000 Series
• 25-74 = Dual Digit Number indicative of stack positioning / performance (non-linear)
• 1/2 = Generation
• P = Single Socket, not present in Dual Socket

AMD is introducing 19 total CPUs to the Rome family, 13 of which are aimed at the dual socket market. All CPUs have 128 PCIe 4.0 lanes available for add-in cards, and all CPUs support up to 4 TiB of DDR4-3200.

The top part is the EPYC 7742, which is the CPU we were provided for in this comparison. It is the most expensive non-custom AMD CPU ever. We will discuss whether the price is a bargain or suitable after we have done some benchmarking. 

But one thing is for sure: AMD is definitely improving the performance per dollar. The real star is the 7502, as it offers 32 Zen2 cores at 2.50/3.35 GHz for $2600. This means that you get higher clocks, better cores, twice the L3, and just as much cores as the 7601 had - in other words, the 7502 is better in every way, but compared to the 7601 it comes with an impressive 40% discount ($2600 vs $4200). 

There is more to it. Unlike Intel's market segmentation strategy, which makes the life of enterprise infrastructure people more complicated than it should be, AMD does not blow fuses on cheaper SKUs to create artificial 'value' for buying more expensive SKUs. The cheapest 8-core 7252 has all 128 PCIe 4.0 lanes, it supports up to 4 TB per socket, it has infinity fabric at the same speed, and includes all virtualization and security features as the best product.

Comparison to Intel

In the table below we have done a base example comparison with some of Intel's SKU list. Given that Intel is dominant in the market, prospective buyers must get a significant price bonus or significantly lower TCO before they switch to AMD.  

In our comparison, we've also ignored the fact that AMD supports up to 4 TB per socket and has 128 PCIe 4.0 lanes, which it beats Intel on both fronts. While the number of people that will buy 256 GB DIMMs is minimal at best, within the error margin of the market, to us it is simply is ridiculous that Intel expect enterprise users to cough up another few thousand dollars per CPU for a model that supports 2 TB, while you get that for free from AMD. 

Going on paper, especially in the high-end, Intel is completely outclassed. A 28-core Xeon 8276M has a list price of ~$12k, while AMD charges "only" $7k for more than twice as many cores. The only advantage Intel keeps is a slightly higher single threaded clock (4 GHz) and AVX-512 support. You could argue that the TDP is lower, but that has to be measured, and frankly there is a good chance that one 64 core (at 2.25-3.2 GHz) is able to keep with two Intel Xeon 8276 (2x28 cores at 2.2-2.8 GHz), while offering much lower power consumption (single socket board vs dual board, 225W vs 2x165W).  

AMD is even more generous in the mid-range. The EPYC 7552 offers twice the amout of cores at higher clocks than the Xeon Platinum 8260, which is arguably one of the more popular Xeon Platinum CPUs. The same is true for the EPYC 7452, which still costs less than the Xeon Gold 6242.  It is only at the very low end, that the diffences get smaller. 

Single Socket

For single socket systems, AMD will offer the following five processors below. These processors mirror the specifications of the 2P counterparts, but have a P in the name and slightly different pricing.

This table makes also clear how much extra frequency AMD extracted out of the 7 nm TSMC process. The sixteen core EPYC 7302P runs at 3.0 GHz with all cores, while the EPYC 7351 was limited to 2.4 GHz at the same 155W TDP.

Again, the EPYC 7502P looks like one of the best deals of the server CPU market. This SKU can offer a lot of advantages compared to the current dual socket servers.  If offers very potent single thread performance (3.35 GHz boost) and a very high 2.5 GHz when all cores are used, even when running AVX2 code. Secondly, a single socket server has a lower BOM and has lower power consumption (200W) compared to a dual 16-core system. Lastly, it supports up to 1-2 TB realistically (64-128 GB DIMMs) and has ample I/O bandwidth with 128 PCIe 4.0 lanes.