Re: disk i/o performance problem

[Douglas Allan Tutty <dtutty@porchlight.ca>]

On Sat, Jun 02, 2007 at 12:12:50PM -0400, Roberto C. Sánchez wrote:
 
> -T     Perform timings of cache reads for benchmark and comparison pur-
>        poses.   For  meaningful  results,  this  operation  should   be
>        repeated  2-3  times  on  an otherwise inactive system (no other
>        active processes) with at least a couple of  megabytes  of  free
>        memory.   This  displays  the speed of reading directly from the
>        Linux buffer cache without disk  access.   This  measurement  is
>        essentially  an  indication  of the throughput of the processor,
>        cache, and memory of the system under test.  If the -t  flag  is
>        also specified, then a correction factor based on the outcome of
>        -T will be incorporated into the  result  reported  for  the  -t
>        operation.
> 

"essentially an indication of the throughput of the processor, cache,
and memory of the system under test".

Since with both tests its the same hardware, and presumably the same
source of hdparm itself, it could be argued that this also tests the
kernel's speed of handling said cache.

Since, I think, these are both linux kernels, I wonder what the
differences are.  What are the differences in /boot/config-2.6*?

I've never heard of BeOS so don't know anything about it or what its
target market is.

Doug.