Re: Q: Filesystem block sizes available?

[Seth Mos <knuffie@xxxxxxxxx>]

At 16:28 13-11-2001 +0100, Roy Sigurd Karlsbakk wrote:
> > You said in the other mail that you got 30MB/s. That is not right. I
> > already reach about 70MB/sec on a 6 disk 10K RPM raid 10 on hardware raid.
> > Software raid is even faster then hardware raid most of the time.
> > The newer ami megaraid firmware finally does read balancing on all disks
> > instead of one of the raid set drives.
> >
> > A IDE disk already has 30MB/s sequential read so something is really "in
> > the way". You have the disks on multiple scsi channels over multiple cards
> > which are 64 bit PCI cards ofcourse. :-)
> > What motherboard do you use?
>
> It's a Compaq ProLiant DL380 with three PCI host bridges, dual channel
> memory ports, and an integrated Compaq RAID controller. The controller is
> on the 32bit/33MHz bus, but it shouldn't be any problem...

Do you use the raid controller? Most of the time they are underpowered for 
the task at hand and the 32 bit 33Mhz PCI bus will limit the bandwidth to 
133MB/sec.

64Bit PCI raid controllers give you a lot of headroom when reading files 
which can be read from the controller cache as well and are limited by the 
PCI bus bandwidth.

In my case this is 533MB/sec (64Bit/66Mhz) from a Dell PE 2500 with a AMI 
Megaraid elite 1600.

I get a amazing read speed of 600+MB/sec with files that still fit into the 
memory cache. How many gigabytes of ram does your box have?

This is with the 2.4.9 kernel which is currently available under testing.

Cheers

--
Seth
Every program has two purposes one for which
it was written and another for which it wasn't
I use the last kind.