Re: 3ware escalade vs software raid, from a different jeff

On Thu, 19 Feb 2004 at 7:38pm, Jeff Garzik wrote

Rev. Jeffrey Paul wrote:

quoted

I am looking at a four disk raid5 or raid10, and it seems like 
the interrupt load from four drives on four channels might be a bit 
excesive.  I'm going to be running critical services on the machine 
that the drives are in (namely mysql and nfs) and don't want to worry 
about performance.

Once your spindles can max out your PCI bus bandwidth, -then- you can 
start worrying about PCI bandwidth and interrupt load ;-)

With some boards, it's actually pretty easy to do that.  ;)  Not with 4 
disks, as the OP is doing, but 8 disks on one 64bit/33MHz bus (3ware 
7500-8) can start to bump up against the PCI bandwidth.  I've got a couple 
servers with 2 3wares and 16 disks, and I need to put the 3wares on 
separate PCI busses to make sure I get the full speed out of the combined 
array (hardware RAID5, software RAID0).

-- 
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University