AMD Rome Second Generation EPYC Review: 2x 64-core Benchmarked
by Johan De Gelas on August 7, 2019 7:00 PM ESTPCIe 4.0
As the first commerical x86 server CPU supporting PCIe 4.0, the I/O capabilities of second generation EPYC servers are top of the class. One PCIe 4.0 x16 offers up to 32 GB/s in both direction, so each socket offers up to 256 GB/s in both directions, for a full 128 PCIe 4.0 lanes per CPU.
Each CPU has 8 x16 PCIe 4.0 links available which can be split up among up to 8 devices per PCIe root, as shown above. There is also full PCIe peer-to-peer support both within a single socket and across sockets.
With the previous generation, in order to enable a dual socket configuration, 64 PCIe lanes from each CPU were used to link them together. For EPYC, AMD still allows for 64 PCIe lanes to be used, but these are PCIe 4.0 lanes now. There is also another feature that AMD has here - socket-to-socket IF link bandwidth management - which allows OEM partners to design dual-socket systems with less socket-to-socket bandwidth and more PCIe lanes if needed.
We also learned that there are in fact 129 PCIe 4.0 lanes on each CPU. On each CPU there is one extra PCIe lane for the BMC (the chip that controls the server). Considering we are living in the age of AI acceleration, the EPYC 7002 servers will be great as hosts for quite a few GPUs or TPUs. Density has never looked so fun.
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negusp - Wednesday, August 7, 2019 - link
hard F in the chat for intel Replypancakes - Wednesday, August 7, 2019 - link
F in chat for wallets of people running Windows server Replyazfacea - Wednesday, August 7, 2019 - link
windows server in 2019 LUL Replydiehardmacfan - Wednesday, August 7, 2019 - link
on-prem Windows Server is probably at an all time high in 2019? Replyazfacea - Thursday, August 8, 2019 - link
desperate for a comeback huh? cool hold your 10% tight and gloat about upcoming bfloat16 Replydiehardmacfan - Thursday, August 8, 2019 - link
Sorry, who is desperate for a comeback? Bring up a floating point format when called out on the ridiculous notion that Windows Server isn't still a large part of the marketplace? say wha Replymkaibear - Thursday, August 8, 2019 - link
Just hopping in to say that I am an IT manager for a major employer in the UK and of our 1800 servers more than 80% of them are Windows... this is not a trend which I see changing any time soon. Replynpz - Thursday, August 8, 2019 - link
Many smaller IT depts in smaller companies use Windows because of familiarity for desktop support such as Active Directory for domains, but none of major critical data center centric, HPC, military, infrastructure are running Windows. Most especially not with EPYC since the Windows scheduler is broken. ReplyManch - Thursday, August 8, 2019 - link
NPZ, You may be speaking for your bubble, but not for the rest. Replyblaktron - Thursday, August 8, 2019 - link
this is 100% false. I do infrastructure consulting for 9 figure companies and they are all primarily windows in their corporate infrastructure. all of them. the only linux you will find in the Fortune 50 is legacy applications and web presentation layer. There are exceptions, but that's true enough to form a rule. Reply