Re: raw/block device disc troughput

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

> What's "od="?
Fat fingers. of=, or course.

> Not awfully surprizing given your setup.
Ah, good.

> Keep in mind mpt uese a rather inefficient communication protocol and does
> tagged queuing.
You mean the protocol the main CPU uses to communicate with an MPT adapter is
inefficient? Or do you mean SAS is inefficient?

> The former means the overhead for each command is not so good, but the
> latter means it can keep lots of commands in the air at the same time. 
I'm sorry, I'm unable to conclude why this explains my results.

> Now you're just complicating things 8^).
Sometimes, probably.

> Let's see, RAID 1 is striping.
Sorry, RAID 1 is mirroring.
So, everything needs to be sent to two discs in parallel. I can't believe
the CPU-HBA communication being a bottleneck?