daveh@cbmvax.UUCP (Dave Haynie) (08/19/89)
Some nice folks borrowed an A2630 and compared it to their A2620 in the same
system. The disk controller is a 2090A. DiskPerf sez:
A2620, 4 Megs:
1024K Reads 509875 Writes 371800 b/sec
A2630, 4 Megs:
1024K Reads 853333 Writes 503606 b/sec
I did tweak DMA a bit on the A2630 design, but I'm still impressed. The drive
used was a Fujitsu SCSI drive I'm not familiar with, and the 2090A ROM wasn't
translated into 32 bit RAM, so it might still go a tad faster.
--
Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests"
{uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy
We have no choice. We are, after all, professionals.swarren@eugene.uucp (Steve Warren) (08/21/89)
In article <7701@cbmvax.UUCP> daveh@cbmvax.UUCP (Dave Haynie) writes: >A2630, 4 Megs: > > 1024K Reads 853333 Writes 503606 b/sec Awesome. $? --Steve ------------------------------------------------------------------------- {uunet,sun}!convex!swarren; swarren@convex.COM
mcp@ziebmef.mef.org (Marc Plumb) (08/29/89)
In article <1555@convex.UUCP> swarren@eugene.UUCP (Steve Warren) writes: >In article <7701@cbmvax.UUCP> daveh@cbmvax.UUCP (Dave Haynie) writes: >>A2630, 4 Megs: >> >> 1024K Reads 853333 Writes 503606 b/sec >Awesome. $? I beg to differ. Steve Beats gave me a figure of 1.2 MB/sec at the Exec device driver level for reads from a CDC Wren III using a 2090A. On a 7.14 MHz 68000. An awesome file system should be able to do at least 1MB/sec on the same hardware on a 90% full disk. 1 MB/sec at all is decent, but the true awesomeness of a file system comes when it has to cope with full disks. I don't know if he has the time, but I hear Steve is dreaming about something better. Does anyone else want to give it a go? File system implementation is, from my attempts at research, very poorly researched, but there is some stuff on the Berkeley FFS, and "Disk File Allocation Based on the Buddy System" offers some nice ideas. Personally, I'm convinced of the desirability of extent-based systems with background incremental disk "optimisation". But if you have a contrary opinion, go to it! -- -Colin Plumb