3 ms·
A step between RAM and SSD could be "Your data fits in RAM in compressed form". LZ4 compression is takes 3-4x longer than memcpy. LZ4 decompression is only 50%
by vardump 11y ago
A step between RAM and SSD could be "Your data fits in RAM in compressed form". LZ4 compression is takes 3-4x longer than memcpy. LZ4 decompression is only 50% [1] slower. 2-3 GB/s per core.
[1]: Your mileage may vary.
- bpicolo 11y agoIf it's slower both in and out what's the benefit? To guy below me: Ah, thanks. I thought the guy above was trying to say it's slower than paging to disk. : )
- jhgg 11y agoBecause it's so much faster than having to go to disk.
- peapicker 11y agoBasically, parsing the percentages, using compressed data in RAM is ~1 order of magnitude slower to get into memory, and less than 1 order of magnitude slower to read from RAM. That is still around 2 (or more depending on setup) orders of magnitude faster than the hit to go to SSD / SSD RAID. Useful knowledge on latency: https://gist.github.com/jboner/2841832 https://gist.github.com/jboner/2841832