Messages in this thread | | | Date | Tue, 25 Nov 1997 18:35:37 -0500 | From | mlord <> | Subject | Re: How does on get a HD running at a descent speed |
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Zlatko Calusic wrote: > > jan gyselinck <JAN.GYSELINCK@student.kuleuven.ac.be> writes: ... > > If anyone knows how I could get some descent speed with my HD, > > say it (I read the list, no need to CC to me).
The original posting mentioned DOS using mode3, but the numbers shown (240us/cycle) were slower than mode3 (180ns).
> My magic recipe is: > > hdparm -u1 -m16 -a16 -A1 -c1 /dev/hda > > Though your mileage may vary, of course. ... > Notice how %CPU columns have lower values, even with better I/O > throughput. Tested disk is IBM DAQA33240 (3.2GB).
The %CPU is not a meaningful measure here, though it probably does reflect lower overall CPU usage in this example (think about it.. with an infinitely fast disk (eg. ramdrive), CPU will be 100% simply because I/O takes no time..)
In this case, the reduced CPU is attributable to the -m16 parameter, which basically cuts the IDE interrupt overhead down to as little as (in this case) 1/16th that of the default setup. -- mlord@pobox.com The Linux IDE guy
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