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Is there any implication for a Windows developer for NUMA supported CPU architecture if only one CPU is present?

Boppity Bop
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  • I'm not aware of any single-socket systems that are NUMA. It's possible to have a multi-socket NUMA machine with only one socket populated. But then it's no longer NUMA because there's only one memory bank. – Mysticial Jun 18 '12 at 16:27
  • yes that was the question. thank you. if you just please write it as an answer I'll mark it – Boppity Bop Jun 18 '12 at 18:01

1 Answers1

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Comment -> Answer

As far as I know, there are no single-socket systems that are NUMA. The IBM Power7 has a slightly NUMA L3 cache, but access to main memory is still uniform.

Many of the multi-socket motherboard systems are NUMA where each socket has its own bank of local and fast memory. You can choose to populate only one socket, but then it's no longer NUMA.

So no, if there's only CPU, then you don't need to worry about NUMA.

Mysticial
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    As of 2017, things are starting to change a bit. Knights Landing Xeon Phi can be configured for 4 NUMA nodes that apply to the MCDRAM. AMD Naples is expected to be configurable for 4 NUMA nodes on each socket. But it's unclear whether this is only for the L3 cache or for the 4 memory channels as well. The large core-count Intel servers have a "cluster on die" mode that can split up a socket into multiple NUMA nodes. Also unclear if it's just the L3 or the individual memory channels as well. – Mysticial Jun 16 '17 at 15:50
  • The same goes to AMD. I have a Dell WS with CascaceLake Xeon, and NUMA can be anabled, however it is not explained in which mode works in. Dell website is also silent on this topic. Maybe it is just BIOS capability for DP configuration. (my CPU is 1S-only btw) – Asdf Dec 18 '20 at 01:52