[Asterisk-Users] TDM400P and SCSI/SATA = * noise problems???

[Damian Funnell]

Hi everyone,

For anyone who was following the earlier thread about noise problems on 
*, here's a little gem from Digium support.

In a nutshell Digium told us that they thought that low accuracy results 
from zttest were the cause of noise problems that we have been 
experiencing.  We re-configured the box to give the TDM400P its own IRQ, 
but found that the zttest results were still lower than what Digium 
recommended they should be.  When I asked them for further information 
on how to improve this they replied:

** Extract begins **

SCSI RAID can cause the problem.  If disabling hyper threading does not 
resolve your problem my next suggest would be to revert to a PATA IDE 
hard drive solution configured to UDMA level 2 using hdparm.  SCSI or 
SATA causes problems on some systems from what I have seen.  The problem 
increases when using a SCSI or SATA RAID.

** Extract ends **

I really hope that they are wrong, as I don't feel like throwing away my 
nice expensive Ultra320 SCSI RAID controller and hot plug drives and 
replacing them with some crusty old IDE config.  Needless to say I'm not 
going to go and shell out on IDE controller & drives until I'm a little 
more certain that this is actually a problem and have asked them for 
more information.

Does anyone else find it odd that the TDM could possibly have a problem 
sharing a box (but not an IRQ) with a SCSI controller?

Combined with the fact that they have also recommended that we turn off 
hyper threading (also causes problems with TDM, apparently), I'm 
wondering if these cards shouldn't come with a warning not to use 
anything with half decent performance in your * server!