poor fdc(4) performance

Pyun YongHyeon pyunyh at gmail.com
Sat Nov 12 07:45:27 GMT 2005

On Sat, Nov 12, 2005 at 06:37:11PM +1100, Peter Jeremy wrote:
 > On Sat, 2005-Nov-12 16:18:15 +0900, Pyun YongHyeon wrote:
 > >I encountered a P3 SMP system that shows poor fdc(4) performance.
 > >But when I use larger block size, say 36b, it seems it works
 > >as expected.
 > 36b is one track.  My suspicion is that the system isn't fast enough
 > to read sequential blocks, one at a time, so you're forced to wait
 > a complete revolution (plus a bit) for each block you read.

Yes, it could be. But I think the machine is fast enough to read
sequential blocks.
Part of dmesg shows:

CPU: Intel Pentium III (800.03-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0x686  Stepping = 6
real memory  = 402587648 (383 MB)
avail memory = 384385024 (366 MB)
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1

And I think I got much better result on slow i386 machines except this one.
Pyun YongHyeon

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