[Dovecot] dovecot vs qpopper performance testing results

[Peter Fern]

Thanks for the info, that's why we love Dovecot ;)

asko wrote:
> Hi,
>
> I did some performance testing with dovecot and qpopper, if anyone is 
> interested..
>
> Hardware: Dual Xeon 2.8 with HT enabled (dmesg sees 4 cpu-s), 1 GB 
> RAM, SCSI RAID 1 with 2x Maxtor Atlas 10K V disks.
>
> Software:  CentOS 4.3, Qpopper 4.08 in standalone mode vs Dovecot 
> 1.0-0_19.rc6, ext3 filesystem
>
> Mailbox format Mbox, tested Pop3 with PAM authentication
>
> My setup had 15 test users with 15 identical 40 MB mbox files. Each 
> mbox had 370 messages, 35 % of them had attachments. So average 
> message size is about 110 KB, average attachment size 220 KB.
>
> "rabid" utility is part of postal package 
> (http://www.coker.com.au/postal/). Command line, which fetches and 
> deletes all the messages from users in the textfile:
>
> rabid -p 1 192.168.x.x ./users -
>
> Resulting fields are:
> time,messages,data(K),errors,connections,SSL connections,IMAP connections
>
>
>
>
> Results (only the best one shown):
>
> Qpopper:
>
> 1 parallel processes:
> 12:36,1020,111470,0,6,0,0
>
> 5 parallel clients:
> 12:44,3246,366207,0,13,0,0
>
> 15 parallel clients:
> 13:06,4099,481347,0,48,0,0
>
>
> Dovecot:
> p1:
> 12:19,3316,367859,0,13,0,0
>
> p5:
> 12:50,4653,524456,0,34,0,0
>
> p15:
> 12:56,5063,578889,0,84,0,0
>
>
>
>
> As you can see, Dovecot is faster.. With 15 parallel processes it 
> seems to have saturated my 100Mbit/s LAN (578889 kB data in one 
> minute). Dovecot had noticeably smaller disk IO and system load was 
> smaller too, probably thanks to smaller IO.
>
> Qpopper performed better than I hoped.. It is probably due fast disks 
> of the test system, I wouldn't expect such numbers using single IDE disk.
>
> Conclusion: The hardware was too fast for testing, LAN became a 
> bottleneck atleast once. The results could be different with different 
> mbox structure.. Anyway, I was convinced, Dovecot wins.
>
> -- 
> asko