[Samba] Horrendously slow transfer speeds in FC3 is driving me crazy!!! Please help...

pb peter at bqdesign.com.au
Fri May 13 10:55:32 GMT 2005


I found that for a modern PC running zero loads,
(my server is a P4 3.2 with 512 M dual channel RAM
an Intel Etherpro Express 100 nic, serving cached disk files from RAM)
samba could be 30% slower than it should be.
It would serve data at about 7 MBytes/sec compared with the old NT4
sever (same Intel nic, 512 RAM, P2/266 Cpu, NT4 with SP6a) that
would do it at 10 Mbytes/sec under all circumstances..
In both cases, CPU usage during transfers were very low. The P4 was 
something like 1% and the NT4 box ran at about 20%.

I found that the network wiring and the quality of the hubs and switches 
is important. When getting data from the samba server, via a cheapie 8 
port switch, the data rate was reduced. When getting data from the samba 
server via a slightly more expensive -but still cheap - 8 port
switch the speed increased to about 9 Mb/sec.
It seems the cheap switches that we buy here for about $50 AU are ok for 
home use but struggle when you want to put them in working situtations.

When trying to improve upon the 7 Mbyte/sec I found that nothing helped 
at all. Compiling with different flags (O3, etc), made no difference 
(cpu load very low anyway) Kernel made no difference (I used Slakware's 
v.8, v.9 and currently use v.10) With or without Hyperthreading on the 
P4 enabled (via custom kernels) made no difference.Different 100TX patch 
cables made no difference.
It was the crap switch in my case.
I had normal speeds when using clients from three cheap switches 
distant, but slow (7 Mb/s) when testing in the server room, via the crap 
switch.
Client PC speed is not important either, anything with clock speeds more 
than about 2-300 Mhz should easily get 10 Mbytes/sec, when running under 
Win98.

Peter.



More information about the samba mailing list