Re: IDE disk speed 5% slower in 1.99.7

Ingo Molnar (
Sun, 26 May 1996 16:43:53 +0100 (GMT+0100)

On Sat, 25 May 1996 wrote:

> To help me decide whether to include /dev/random in my kernel I wanted to
> measure how it affected disk access speed. To do it I ran hdparm -t on my
> IDE drive with a freshly booted computer that was otherwise idle.
> The speed increase obtained by removing /dev/random from the kernel was
> too low to distinguish from measurement error but when I performed the
> same experiment running 1.2.13 I got a 5% speed improvement.

thats probably due to the buffer cache code change. (using a unified
buffer cache for most data).

the second value in "hdparm -t" shows the "raw buffering throughput". This
is now a bit slower. This change shows up in the "summary value" too.

-- mingo