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If your building software as a service that changes this calculus a fair bit. You only need to wait for AWS/Azure/GCP/CSP of choice to support the hardware (you

If your building software as a service that changes this calculus a fair bit. You only need to wait for AWS/Azure/GCP/CSP of choice to support the hardware (you don't need to wait for mass market use of it). For example, many (all?) database as a service offerings now days run on very precisely configured hardware.

Const-me 5y ago
> many (all?) database as a service offerings now days run on very precisely configured hardware I'm not sure AVX512 is a win even in that case. AMD Epyc peaks at 64 cores/socket, Intel Xeon at 40 cores/socket. It's not immediately obvious AMD's performance advantage over Intel is smaller than the Intel-only win from AVX512.
- dragontamer 5y ago
  Are sockets the best measurement? AMD has a pretty complex network inside that socket: 8 dies + a switch. The Xeon 40 core is just one die, which means L3 cache and memory is more unified. L3 cache is probably king (data may not fit, but maybe some indexes?), but it's not obvious if EPYCs separate L3 caches are comparable to Xeons (or Power)
  - Const-me 5y ago
    AMD is much faster overall. This page has a benchmark of a MySQL database, the slide is called MariaDB: https://www.servethehome.com/amd-epyc-7763-review-top-for-this-generation/2/ https://www.servethehome.com/amd-epyc-7763-review-top-for-th... The only benchmark where AMD didn't have substantial advantage is chess, I think the reason is AMD's slow pdep/pext instructions.
    - dragontamer 5y ago
      The 6258R is just 28 cores though, 56 total after dual socket. AMD Zen3 has single cycle pext / pdep now and the chess benchmarks are better as a result.
      - Const-me 5y ago
        Good point. Indeed, for DB-only workloads the Xeon appears to be better: https://www.phoronix.com/scan.php?page=article&item=intel-xeon-8380-linux&num=6 https://www.phoronix.com/scan.php?page=article&item=intel-xe... Still, this doesn’t mean Epyc is only good for HPC, e.g. this is some enterprise Java-based benchmark where it’s substantially faster: https://www.anandtech.com/show/16594/intel-3rd-gen-xeon-scalable-review/9 https://www.anandtech.com/show/16594/intel-3rd-gen-xeon-scal... BTW, on my job I don’t do databases, but I do quite a lot of HPC stuff.
        dragontamer 5y ago
        Add to the fact that MariaDB doesn't have AVX512 instructions used yet, and you can see that Intel's unified L3 cache is just better for database-like workloads than AMD's split L3 cache. x265 is more of an AVX512 test scenario, which the Xeon 40-core also is demonstrating proficiency at over and above the EPYC 64 core. ------------ I'm mostly impressed at how well the split "chiplet" strategy is doing in all the other benchmarks however. The AMD "I/O die" is clearly a winner. Its probably not a latency winner, but it is efficiently giving the memory bandwidth and distributing it to all of the dies.

Const-me 5y ago

> many (all?) database as a service offerings now days run on very precisely configured hardware I'm not sure AVX512 is a win even in that case. AMD Epyc peaks at 64 cores/socket, Intel Xeon at 40 cores/socket. It's not immediately obvious AMD's performance advantage over Intel is smaller than the Intel-only win from AVX512.

dragontamer 5y ago
Are sockets the best measurement? AMD has a pretty complex network inside that socket: 8 dies + a switch. The Xeon 40 core is just one die, which means L3 cache and memory is more unified. L3 cache is probably king (data may not fit, but maybe some indexes?), but it's not obvious if EPYCs separate L3 caches are comparable to Xeons (or Power)
- Const-me 5y ago
  AMD is much faster overall. This page has a benchmark of a MySQL database, the slide is called MariaDB: https://www.servethehome.com/amd-epyc-7763-review-top-for-this-generation/2/ https://www.servethehome.com/amd-epyc-7763-review-top-for-th... The only benchmark where AMD didn't have substantial advantage is chess, I think the reason is AMD's slow pdep/pext instructions.
  - dragontamer 5y ago
    The 6258R is just 28 cores though, 56 total after dual socket. AMD Zen3 has single cycle pext / pdep now and the chess benchmarks are better as a result.
    - Const-me 5y ago
      Good point. Indeed, for DB-only workloads the Xeon appears to be better: https://www.phoronix.com/scan.php?page=article&item=intel-xeon-8380-linux&num=6 https://www.phoronix.com/scan.php?page=article&item=intel-xe... Still, this doesn’t mean Epyc is only good for HPC, e.g. this is some enterprise Java-based benchmark where it’s substantially faster: https://www.anandtech.com/show/16594/intel-3rd-gen-xeon-scalable-review/9 https://www.anandtech.com/show/16594/intel-3rd-gen-xeon-scal... BTW, on my job I don’t do databases, but I do quite a lot of HPC stuff.
      - dragontamer 5y ago
        Add to the fact that MariaDB doesn't have AVX512 instructions used yet, and you can see that Intel's unified L3 cache is just better for database-like workloads than AMD's split L3 cache. x265 is more of an AVX512 test scenario, which the Xeon 40-core also is demonstrating proficiency at over and above the EPYC 64 core. ------------ I'm mostly impressed at how well the split "chiplet" strategy is doing in all the other benchmarks however. The AMD "I/O die" is clearly a winner. Its probably not a latency winner, but it is efficiently giving the memory bandwidth and distributing it to all of the dies.