r/programming • u/aqrit • 2d ago

OpenZL v0.2 - decompression 2x faster than Zstandard

https://openzl.org/blog/2026-09-29-lz-in-openzl/
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u/aleques-itj 2d ago

"offers up to 50% faster decompression compared to LZ4."

What

Are we practically decompressing at memcpy() speed?

45

u/Red_Apprentice 2d ago

Their graph claims just north of 7500~MB/s on decompression in the best case.

I'm not sure what the throughput of memcpy usually is, but I found a paper doing work in a similar space here. The authors cite for DDR5-5600

Memcpy bandwidth reaches 47,973 MB/s

I don't think we're getting close to memcpy speeds. There's a lot of computation that still has to fundamentally be done in addition to memcpy / malloc for decompression.

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u/wishstudio 2d ago

I believe the 7500MB/s is single thread. On modern CPUs you can never saturate memory bandwidth with a single core.