RA90's

[Alan's Home for Wayward Notes File.]

In article <618 at tijc02.UUCP>, cgh018 at tijc02.UUCP (Calvin Hayden ) writes:
> Any one out there who can tell me the optimal
> rotational gap, and blocks/cylinder for a DEC
> RA90 Drive?  

	I use an 8 KB block size on my RA90's and the file
	system code uses an 8 KB gap.  I've played around
	with smaller (0) and larger gaps without much change
	in sequential I/O speed.  I haven't tried other block
	sizes.

	From the V3.1 disktab entry for the RA90:

ra90|RA90|DEC RA90 Winchester:\
	:ty=winchester:ns#69:nt#13:nc#2649:\
	:pa#15884:ba#8192:fa#1024:\
	:pb#127072:bb#4096:fb#1024:\
	:pc#2376153:bc#8192:fc#1024:\
	:pd#420197:bd#8192:fd#1024:\
	:pe#420197:be#8192:fe#1024:\
	:pf#840393:bf#8192:ff#1024:\
	:pg#1680787:bg#8192:fg#1024:\
	:ph#552410:bh#8192:fh#1024:

	Sectors per track is 69, tracks per cylinder is 13 and
	there are 2649 cylinders.
-- 
Alan Rollow				alan%nabeth.dec.com at decwrl.dec.com