ide-speed was Re: Interrupt hick ups

"Timothy A. Seufert" wrote:

At 9:56 AM +0200 6/16/00, Martin Costabel wrote:

quoted

What is gone too, unfortunately, is the phenomenal IDE speed
improvement. In late 2.3.99/early 2.4.0-test1, I had a "hdparm
-t"-measured throughput more than 3 times as high (almost 6MB/sec,
sometimes more) as with 2.2.x (1.90MB/sec). It diminished in -ac15
(3.25MB/sec), and in -ac16 it is almost back down (2.30MB/sec) to the
2.2.x values.

Have you made sure your HD is set up for DMA, etc.?  For example, do
"hdparm -d1 -u1 -m16 -p4 /dev/hda" and then run the -t throughput
test.  (Use the man pages to make sure those are sane options, that's
all from memory.)

I remember similar fluctuation in 2.2.x as automatic negotiation of
DMA and so forth was first put in then taken out of the IDE driver.

Also, to make sure buffers get flushed before a test (for repeatable
results) you should do hdparm -Tt, not just hdparm -t.

Aha, just made a test and saw the same as Martin. Now with the hint from
Tim I get back to 6.30MB/s on ac19
On 2.2.16 it is still 6.xMB/s.
So now the question is for me what does the kernel parameter
hda=autotune do?
Do I always have to set this line by 'hand'(script) "hdparm -d1 -u1 -m16
-p4 /dev/hda"?

Thanks
Andreas

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