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A massive power and CPU load decrease in Zstandard is a big win for Intel. AMD has been racking up major pluses in the enterprise space, with RAM, PCIE and core

by berbec 3y ago

A massive power and CPU load decrease in Zstandard is a big win for Intel. AMD has been racking up major pluses in the enterprise space, with RAM, PCIE and core count advantage. Showing that any Intel is faster at such a major CPU load task is a big deal. That's not to detract from everything AMD has done, but hardware is only the first step. Software that properly uses the features your hardware provides is just, if not more, important. I love the fact AMD is pushing Intel so much. Pre-C2D days were amazing because we had two vibrant, innovative companies pushing to the edge of possible; trying to out-do each other. Pre-Ryzen was a horrible time. Do you want to spend $500 to upgrade from a 4-core intel 4000-cpu to an intel 5000-cpu? You'll get DDR4 and 1% IPC. Now we get massive IPC, clock speed, ram and PCIE improvements on a regular basis. Competition is great, especially for the consumer.

jiggawatts 3y ago
From the benchmarks I’ve seen, QAT is a desperate attempt to gain some competitive advantage over AMD. It’s not clear if there is any actual advantage for real workloads. Sure, benchmarks of pure compression will come out ahead for Intel, but a typical sever running something like a database engine with compressed disk storage is likely a win for AMD. The new EPYC 9004 chips are much cheaper than the Intel CPUs with QAT, and they have more cores, and much higher clock speeds. It’s hard to believe there’s any scenario where the Xeon CPUs provide better overall value…
- nvm0n2 3y ago
  How is compression not a real workload? Zstd is an excellent codec that's rapidly proliferating - for example Chrome is integrating it at the moment. https://bugs.chromium.org/p/chromium/issues/detail?id=1246971 https://bugs.chromium.org/p/chromium/issues/detail?id=124697... Relatively few servers run databases. Many more are running web servers and given the huge efforts web devs go to in order to optimize response sizes, much faster, lower power and lower latency compression seems like an instant win. All that's required is for web servers to integrate the zstd library and this QAT thing, and that can be enough to tip the balance especially for IO bound servers that are mostly just doing string interpolation and waiting for backends. And you mention a DB with compressed disk storage. How is better compression not a huge win for that use case? Databases are usually disk IOP, latency and CPU power constrained, and this is a win for all of those cases. Finally, clearly this tech can be applied to other algorithms not just zstd. Presumably they highlight zstd because the library is actively maintained and was willing to add this (probably single use) "plugin" API. Really they should have just integrated it directly instead of complicating things for every zstd user, but I guess it adds extra dependencies or increases code size or something. The wins are big enough that other codec libraries will probably use the same approach and eventually it'll be abstracted by APIs that are less code size sensitive. Yes, AMD is doing great right now, but Intel have had an edge when it comes to specialized CPU features for a long time. For example AMD are only just now catching up to where Intel were with SGX 8 years ago.
  - saagarjha 3y ago
    > For example AMD are only just now catching up to where Intel were with SGX 8 years ago. Ah yes, being hopelessly broken?
    - nvm0n2 3y ago
      Other way around. AMD's early efforts were hard broken and needed a new CPU, SGX has never been as far as I know. Even when not technically "broken" AMD SEV was broken by design because it didn't protect all the necessary state. SGX was correctly designed from day one and was always patchable via their TCB recovery process = software upgrade, sufficiently well that it could be patched to recover from Spectre attacks despite nobody knowing about them at the time SGX was designed. But that was just an example. Intel have introduced a quite a few interesting CPU extensions and special bits of hardware that AMD had no answer for over the years.
  - ksec 3y ago
    >How is compression not a real workload? Not parent, but I guess what he / she meant was total workload. E.g, If 100% of your workload, only 5% of that is compression, speeding it up by 5x will only give you a 4% reduction in total system workload. Which means other factor like clock speed, more core, cache etc in a different system could still win despite it lost the compression benchmarks.
- tecleandor 3y ago
  I think it's great for some pieces of the puzzle: - CDNs, webservers and/or load balancers: SSL termination and compression acceleration for serving content - VPN nodes: Encryption acceleration - Storage: Compression acceleration It's sad they stopped making PCIe cards, and the older PCIe cards aren't compatible with the new drivers and "hardware revision". You could combine AMD processors with Intel QAT acceleration.
  - wbl 3y ago
    Traversing the PCI bus and waiting for interrupt handling on completion add costs. What you really want is to shove the encyption to the NIC so the data comes out of main memory and never returns.
    - tecleandor 3y ago
      You could probably do that with one of those DPU/SmartNICs, like the AMD Pensando or the Mellanox ConnectX

by berbec 3y ago

jiggawatts 3y ago

From the benchmarks I’ve seen, QAT is a desperate attempt to gain some competitive advantage over AMD. It’s not clear if there is any actual advantage for real workloads. Sure, benchmarks of pure compression will come out ahead for Intel, but a typical sever running something like a database engine with compressed disk storage is likely a win for AMD. The new EPYC 9004 chips are much cheaper than the Intel CPUs with QAT, and they have more cores, and much higher clock speeds. It’s hard to believe there’s any scenario where the Xeon CPUs provide better overall value…

nvm0n2 3y ago
How is compression not a real workload? Zstd is an excellent codec that's rapidly proliferating - for example Chrome is integrating it at the moment. https://bugs.chromium.org/p/chromium/issues/detail?id=1246971 https://bugs.chromium.org/p/chromium/issues/detail?id=124697... Relatively few servers run databases. Many more are running web servers and given the huge efforts web devs go to in order to optimize response sizes, much faster, lower power and lower latency compression seems like an instant win. All that's required is for web servers to integrate the zstd library and this QAT thing, and that can be enough to tip the balance especially for IO bound servers that are mostly just doing string interpolation and waiting for backends. And you mention a DB with compressed disk storage. How is better compression not a huge win for that use case? Databases are usually disk IOP, latency and CPU power constrained, and this is a win for all of those cases. Finally, clearly this tech can be applied to other algorithms not just zstd. Presumably they highlight zstd because the library is actively maintained and was willing to add this (probably single use) "plugin" API. Really they should have just integrated it directly instead of complicating things for every zstd user, but I guess it adds extra dependencies or increases code size or something. The wins are big enough that other codec libraries will probably use the same approach and eventually it'll be abstracted by APIs that are less code size sensitive. Yes, AMD is doing great right now, but Intel have had an edge when it comes to specialized CPU features for a long time. For example AMD are only just now catching up to where Intel were with SGX 8 years ago.
- saagarjha 3y ago
  > For example AMD are only just now catching up to where Intel were with SGX 8 years ago. Ah yes, being hopelessly broken?
  - nvm0n2 3y ago
    Other way around. AMD's early efforts were hard broken and needed a new CPU, SGX has never been as far as I know. Even when not technically "broken" AMD SEV was broken by design because it didn't protect all the necessary state. SGX was correctly designed from day one and was always patchable via their TCB recovery process = software upgrade, sufficiently well that it could be patched to recover from Spectre attacks despite nobody knowing about them at the time SGX was designed. But that was just an example. Intel have introduced a quite a few interesting CPU extensions and special bits of hardware that AMD had no answer for over the years.
- ksec 3y ago
  >How is compression not a real workload? Not parent, but I guess what he / she meant was total workload. E.g, If 100% of your workload, only 5% of that is compression, speeding it up by 5x will only give you a 4% reduction in total system workload. Which means other factor like clock speed, more core, cache etc in a different system could still win despite it lost the compression benchmarks.
tecleandor 3y ago
I think it's great for some pieces of the puzzle: - CDNs, webservers and/or load balancers: SSL termination and compression acceleration for serving content - VPN nodes: Encryption acceleration - Storage: Compression acceleration It's sad they stopped making PCIe cards, and the older PCIe cards aren't compatible with the new drivers and "hardware revision". You could combine AMD processors with Intel QAT acceleration.
- wbl 3y ago
  Traversing the PCI bus and waiting for interrupt handling on completion add costs. What you really want is to shove the encyption to the NIC so the data comes out of main memory and never returns.
  - tecleandor 3y ago
    You could probably do that with one of those DPU/SmartNICs, like the AMD Pensando or the Mellanox ConnectX