PFC, thanks for giving us some real data. May I post it to the lkml thread?
In essence, LZO wins the benchmarks, and the code is hard to read. I guess I have to go with LZO, and encourage people to take a stab at dethroning it. Hans PFC wrote: > > I have made a little openoffice spreadsheet with the results. > You can have fun entering stuff and seeing the results. > > http://peufeu.free.fr/compression.ods > > Basically, a laptop having the same processor as my PC and a > crummy 15 MB/s drive (like most laptop drives) will get a 2.5x speedup > using lzf, while using 40% CPU for compression and 15% CPU for > decompression. I'd say it's a clear, huuuuge win. > > A desktop computer with a modern IDE drive doing 50 MB/s will > still get nice speedups (1.8x on write, 2.5x on read) but of course, > more CPU will be used because of the higher throughput. In this case > it is CPU limited on compression and disk limited on decompression. > However soon everyone will have dual core monsters so... > > A big ass RAID will not get much benefit unless : > - the buffer cache stores compressed pages, so compression > virtually doubles the RAM cache > - or the CPU is really fast > - or you put one of these neat FPGA modules in a free Opteron > socket and upload a soft-hardware LZF in it with a few gigabytes/s > throughput Or you look the sysadmin in the eyes, and say, your file servers have more out of disk space problems than load problems, yes? > > ... > >
