Re: FreeBSD 5.3b7and poor ata performance

Brad Knowles wrote:
> At 6:08 PM -0400 2004-10-25, Charles Swiger wrote:
>>  There's a Sun E450 with ten disks over 5 SCSI channels in the room
>>  next door: one UW channel native on the MB, and two U160 channels
>>  apiece from two dual-channel cards which come with each 8-drive-bay
>>  extender kit. 
> 
>     You've got an average of two disks per SCSI channel, and how many 
> disks per channel on those 8-drive bays?

The Sun E450 base unit came with a 4-drive bay and 1 channel.  Sun sells (or 
sold?) kits that add 8-drive bays & a dual-channel card.  You can put two kits 
in, for a total of twenty drives in the machine, in other words, so this 
particular system is only half-full.

[ If it was full, there would be exactly 4 drives per channel. ]

Hmm, here's a picture of an E450 with one 8-drive bay kit installed; you can 
see the two unused 80-pin SCA connectors where drives 10 and 11 [*] could go:

http://sunsolve.sun.com/handbook_pub/Systems/E450/component.front_open_zoom.html

>>                 It's running Solaris and DiskSuite (ODS) now, but it
>>  would be interesting to put FreeBSD on it and see how that does, if
>>  I ever get the chance.
>  
>     In my experience, ODS never performed quite as good as Vinum, but it 
> would be very interesting to see what kind of performance you can get 
> out of this box using FreeBSD/SPARC64.

Yup.  It would need to stop being used before I can play with it, though.

-- 
-Chuck

[*]: Counting from 0 to 19, of course.