Re: Absolutely horrid IDE performance...

Mark Lord (mlord@pobox.com)
Sat, 05 Dec 1998 00:29:58 +0000

Gerard Roudier wrote:
>
> On Wed, 2 Dec 1998, Mark Lord wrote:
>
> > > -------Sequential Output-------- ---Sequential Input-- --Random--
> > > -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
> > >Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec
> > >%CPU
> > > 256 17374 95.5 32681 33.2 10706 24.3 15683 68.4 23710 24.3 214.6 1.8
>
> Just my comments on this benchmark results:
>
> 1) Block write = 32681 KB/second
> Comment: Not relevant, if as I guess the machine has probably 128 MB
> memory.

Yes, but the same results are achievable on less.
The test file was 256MB. Those are *real* throughput rates,
not buffer-cache buggered speeds.

> 2) Block read 23710 KB/second against Character Read 15683 KB/s
> and only 68.4 % CPU.
> Comment: You should get at least 90 %. Something is behaving not well
> somewhere.

Why should it get 90%? The machine is very fast, and has to wait
sometimes for I/O. Again, no bogosity there.
>
> For your information, here is a benchmark result with Linux 2.1.30 and the
> stock driver I got a couple of days ago using a single Cheatah2.
> (PII 233 / 66MHz SDRAM + 64MB + SYM53C895)
>
> -------Sequential Output-------- ---Sequential Input-- --Random--
> -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
> Machine MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
> 4K ext2 300 10656 97.7 19235 23.7 8346 26.5 13097 91.8 18602 21.0 229.2 4.7

Looks pretty wimpy, even by IDE standards.

-- 
mlord@pobox.com


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