> On Sun, Nov 28, 1999 at 03:14:15AM +0000, Darren Nickerson wrote:
> >
> ...
> >
> > It appears to me that of four identical Maxtor 27GB drives, two will do
> > 66 and two will only do 33:
>
> I've seen others report this as well. But I don't know IDE stuff (I just
> use it and smile when it works ;)
Thanks for the reply Jakob. :-P I used to be the same . . . now I'm bitter and
twisted. Well, mebbe just twisted.
> ATA66 is going to buy you between 0 and 1% performance over ATA33 with any
> current disks. Don't wory, be happy.
I suppose that's true, expecially since I'll never be loading the IDE bus up
much, cuz that would be baaaaaaad for raid. What was I thinking?
> > Even more disappointingly, a raid1 array of hde and hdg shows identical
> > performance to a raid1 array of hdi and hdk.
>
> As stated above, ATA33 and -66 doesn't make a difference with disks that
> couldn't saturate an ATA20 if that one existed.
Yes, good point.
> How ``bad'' is the performance ?
It was at one point about 4MB/s . . . I nuked that kernel ages ago though, and
am back on 2.2.13ac2, which reports itself as 2.2.13ac1, and things are OK
again . . .
> What did you expect ? You drive can transfer something like 15MB/s (give and
> take). Putting it on a bus that can do 66MB/s isn't going to make your drive
> spin faster.
You're right. Somehow I had it into my head that the drive being able to do
ATA66 tranfers would actually improve the rate at which it could spew data.
> Some marketing guys did one hell of a job, promoting ATA66. There's a lot
> of people out there, believing that it makes a difference...
Yup, sorry to have been so naive.
> Oh well, in three years any decent IDE drive will do 50 MB/s from the platter,
> and all those ATA66 cards will come in handy. :)
I live in hope. Disk I/O is such an annoying bottleneck . . . raid makes it
more bearable of course. Benching my raid5 array now . . .
-------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
2000 7818 98.9 31010 28.0 13601 28.3 8328 97.5 36487 26.3 113.4 1.5
I have a feeling this is not bad at all ;-) Time to play witch chunk size and
mke2fs options.
-Darren
