On Sunday, 28 February 1999 at 1:51:45 -0500, Tugrul wrote: > > Seems to work alright here. dmesg and dd tests follow. > > [before] > mercury# dd if=/dev/zero of=/tmp/zero bs=1024k count=32 > 32+0 records in > 32+0 records out > 33554432 bytes transferred in 6.013635 secs (5579725 bytes/sec) > mercury# > > [after] > mercury# dd if=/dev/zero of=/tmp/zero bs=1024k count=32 > 32+0 records in > 32+0 records out > 33554432 bytes transferred in 5.892770 secs (5634706 bytes/sec) > mercury# > > Not much gain with this drive :/
You shouldn't use files to this kind of test. The buffer cache will falsify the results, especially on relatively small transfers. Try a dd to (or from :-) the raw device. The other thing is, of course, that you can't transfer faster than the disk will allow. If you can do that in PIO mode, you won't get any speed improvement with DMA. What you *will* get is a significant drop in CPU load. > Copyright (c) 1992-1999 FreeBSD Inc. > Copyright (c) 1982, 1986, 1989, 1991, 1993 > The Regents of the University of California. All rights reserved. > FreeBSD 3.1-STABLE #0: Sun Feb 28 01:32:47 EST 1999 > galat...@mercury.novastar.com:/usr/src/sys/compile/MERCURY > Timecounter "i8254" frequency 1193225 Hz > CPU: Pentium/P55C (166.45-MHz 586-class CPU) > Origin = "GenuineIntel" Id = 0x543 Stepping=3 > Features=0x8001bf<FPU,VME,DE,PSE,TSC,MSR,MCE,CX8,MMX> Could you send me the output of a verbose boot, please? Greg -- See complete headers for address, home page and phone numbers finger g...@lemis.com for PGP public key To Unsubscribe: send mail to majord...@freebsd.org with "unsubscribe freebsd-current" in the body of the message
