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I wan to disable all hardware prefetching on an AMD Epyc 7702P (Zen 2 / Rome). I don't find anything related in the official tech docs (Processor Programming Reference 17H and Manuals).

However, according to BKDG document for 15h. I have managed to disable the L1 prefetch by writing 1 on bit 13 on MSRC001_1022 (the L1-dcache-prefetches hardware counter gives 0). But the L2 Prefetcher Hits/Miss in L3 hardware counter doesn't change, so I assume that L2 Prefetch is on.

Is there any way to disable L2 prefetch?

In the BKDG document I read about the D18F2x11C. Is this a possibility? If that's the case, how can I do it?

Peter Cordes
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ant
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  • Does setting `MSRC001_101C[DisHwPf]` (bit is no. 23) do anything? – Margaret Bloom Apr 26 '20 at 18:56
  • I can't read the register. Also, I don't find any information about that register on AMD documentation (PPR and BKDG for 15h and 16h). – ant Apr 27 '20 at 17:59
  • It's on the BKDG for 15h model 70h-7fh. [https://imgur.com/a/OQdydDq](https://imgur.com/a/OQdydDq). – Margaret Bloom Apr 27 '20 at 18:38
  • As I recollect this option was present in BIOS of dell and Supermicro. Are you looking for system wide L2 prefetch disable, then use BIOS to disable. can you please check and let us know – Vipin Varghese Feb 03 '22 at 15:57

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