On: Reverse Engineering the Comtech AHA363 PCIe Gzip A...

[tachyonbeam]

I'm curious to know how much faster than Gzip compression on a modern multicore CPU this is. The AHA webpage says "Compresses and decompresses at a throughput rate over 5.0 Gbits/sec" (that's 1.2 GB/s). How fast can you gzip compress on a 16-core Ryzen CPU, for example?

[abiogenesis → tachyonbeam]

I don't think gzip can use multiple cores, but there is a parallel implementation of gzip called pigz (race condition pun?) [1] which uses a clever trick [2] not to reduce compression efficiency:

> The input blocks, while compressed independently, have the last 32K of the previous block loaded as a preset dictionary to preserve the compression effectiveness of deflating in a single thread

[1] https://zlib.net/pigz/

[2] https://zlib.net/pigz/pigz.pdf

[masklinn → tachyonbeam]

According to https://rachaellappan.github.io/pigz/ pigz did about 360MB/s on a 96 cores machine, though that was 3 years ago.

[Ballas → masklinn]

I regularly get 80-200MB/s on my 8 core 7700HQ, though it is likely limited by disk speed.

[Ballas → tachyonbeam]

Looking at the puny heatsink on this card, I call that pretty impressive performance/watt.

(Note that the heatsink is on the FPGA, not the actual gzip accelerator chip.)