On Sun, May 29 2005, Michael Thonke wrote:

quoted

Nothing, unfortunately NCQ doesn't provided any way of doing ordered
tags. The only tunable is the queue_depth, you can set that anywhere
between 1 and 30.

 

So way my drive got default 30 as queue_depth on AHCI as you mentoined
in the next mail
2-4 should be suitable and enough/normal?

Yes, 30 will be default for basically anyone as ahci now advertises a
max depth of 30 and the drives typically all support a depth of 32. The
minimum value of those two is used.

Whether 2-4 is 'enough' depends on your workload. But usually 2-4 is
enough to get a nice speedup on heavier io, while still getting you good
latencies on the individual io.

-- 
Jens Axboe