15:42:33 <nikolam> I have a question about transferring files over SFTP to SmartOS using SSH port on global zone root user. When I disable compression on SFTP in Filezilla on sending side, I get full link speed. When I have SFP compression enabled it starts sending at full speed, then it limits transfer sped at somewhere arount 61 Mbit/s.. 
15:43:30 <nikolam> So question is with illumos ssh server on SmartOS globalzone and SFTP, why transfer is so slower with SFTP compression enabled .. 
15:46:41 <nikolam> When I say compression enabled, it is SFTP settings on Filezilla on the sending side. 
15:58:55 <nbjoerg> data transfer in what direction?
15:59:30 <nbjoerg> 60mbit/s would be a bit on the low end, but compression makes the whole process cpu bound
16:01:38 <nbjoerg> e.g. compressing a 1GB file here takes 30s with a plain gzip -9, that would be like 30MB/s
16:54:21 <nikolam> From Linux desktop to smartos machine 
16:55:10 <nikolam> Well at least with Filzilla to Smartos global zone, over ssh/SFTP it is full speed when not compressed. 
18:55:35 <nbjoerg> compression spends time on the data source side btw
21:32:39 <nikolam> I was thinking compressed SFTP should be faster, not slower.. 
21:34:16 <bahamat> Don't confuse data rate with throughput.
21:37:29 <bahamat> For the uncompressed transfer, sftp may be taking advantage of sendfile(3ext). For compressed, it needs to be read and compressed in userland which induces overhead.
22:47:20 <nbjoerg> compression on semi-modern cpus is orders of magnitude faster than compression (even deflate)
22:47:53 <nbjoerg> only use compression for long distance links of limited bandwidth