AMD introduced the second Epyc generation at the Next Horizon event today. Rome comes with a central management chip and up to 64 cores.
Epyc: AMD Revolutionizes Server CPUs
AMD did a lot right with the Zen architecture. The first CPUs in the form of Epyc, Ryzen and Threadripper caused quite a change in the processor market. Intel finally got the resistance that the market urgently needed. Especially Epyc seemed to be a thorn in Intel’s side. Thus, corporate marketing mocked AMD’s server CPUs as “glued together desktop processors”. The first generation of Epyc uses four dies with eight processor cores each. These are interconnected by an interconnect called Infinity Fabric, resulting in a large CPU. The approach also has some drawbacks, but is much cheaper to produce. It is also easier to achieve a high number of cores. Intel has now also recognized this and presented a Xeon processor with 48 cores consisting of two dies yesterday.
With the second generation of Epyc, AMD is now consistently continuing the MCM approach. The processor manufacturer is revolutionizing the CPU concept once again. This time, eight chiplets are used. The difference is the type of connection. In the middle of the processor is a large management chip that centrally manages the I/O hub and the memory connection. As a result, the latency times of each processor are almost identical. In the previous generation, each die itself addressed a part of the RAM, which led to high latency times if the searched information was in another part of the RAM. In order to accommodate the nine dies at all, AMD manufactures the processor dies with a 7nm structure width. The management chip still comes with a 14nm structure width. Due to the significantly smaller manufacturing process, up to 64 cores are possible on a single processor.
128 PCIe 4.0 lanes and eight-channel memory interface
The memory interface remains fundamentally the same. Epyc 2 continues to support eight memory channels, while Intel’s Cascade Lake-AP already supports a 12-channel interface. On the other hand, AMD is one step further with the PCIe lanes. Rome supports 128 PCIe 4.0 lanes, which are twice as fast as PCIe 3.0. This also fits to the new Vega 20 graphics cards, which also work with PCIe 4.0. AMD has worked on Zen 2 for four years.
There is also a first benchmark already. During the demonstration, an Epyc 2 with 64 cores competed against a dual socket system consisting of Intel Xeon Platinum 8180M with a total of 56 cores. There was also a comparison to a dual socket system with two Epyc 7601 processors with 32 cores each. In the C-Ray benchmark, the Rome processor beat the other two systems by a narrow margin. The Xeon system needed 30 seconds for the calculation, while the 64-core needed 28 seconds. The Epyc 7601 system, which also works with 64 cores, reached a similar value. AMD thus shows that Epyc 2 can easily replace two processors with only one processor. Other benchmarks have not been tested, so no statement can be made about the overall performance of the new Epyc CPUs yet.
Epyc soon to be used in the AWS cloud
AMD also came up with another big surprise at the Next Horizon event. The Epyc processors are now also being used in the cloud service Amazon Web Services (AWS). AMD has thus acquired the largest provider of cloud computing. Epyc servers are already running at providers such as Microsoft Azure or Oracle, but with a market share of over 40 percent, AWS is a different size. Customers can now order two different instance types in the Elastic Compute Cloud (EC2) with Epyc processors.
Specifically, these are the instance types M5a with up to 96 processor cores and 384 gigabytes of RAM and R5a with up to 786 gigabytes of RAM with a maximum of 96 cores. For both systems there is a network connection up to 20 Gbps. The instances are now available and cost 10 percent less than their Intel counterparts. In the future, Amazon will also serve the entry-level class with Epyc. Soon there will also be T3a instances, which can have up to eight cores and 32 gigabytes of RAM. For AMD, the entry into AWS is a very important business and also good for the market, as Intel’s monopoly position is also ended here.