On Thu Apr 9 05:18:31 EDT 2009, bdhee...@gmail.com wrote: > Extraction of only a 180M archive knelled down a 1.8Ghz/P-M4/i686/1Gb > RAM/40GiB IDE HDD machine running vanilla Plan9 installed natively: > > term% cat /dev/sdC0/ctl |grep dma > config 0040 capabilities 2F00 dma 00550020 dmactl 00550020 rwm 8 rwmctl 0 > term% time /n/mon/mnt/sda9/Downloads/Plan9/mroot-linuxemu.tbz2 > ... > 183.27u 31.06s 623.86r tar zxf > /n/mon/mnt/sda9/Downloads/Plan9/mroot-linuxemu.tbz2 > term% ls -l /n/mon/mnt/sda9/Downloads/Plan9/mroot-linuxemu.tbz2 > --rw-rw-r-- M 47 root wheel 188569960 Apr 8 16:15
a laptop drive of that general description is probablly good for 20mb/s sequential io. assuming that the uncompressed archive is 3x larger, you're getting about 1mb/s writes even with the slow decompression. it looks like that archive is pulled over the network. since you have a 3c905, that would be at a maximum of about 10mb/s. if you're linked at 10mb/s, the limit is about 1mb/s. i'd recommend checking the drive's speed with dd. time dd -if /dev/sdC0/data -of /dev/null -count 5000 -bs 64k i don't recall if the 3c905 will tell you its link speed. you can try /dev/kmesg or /net/ether0/ifstats under mbps. the latter may be the maximum mbps the card is capable of, due to the fact mbps is used to size queues. i like the suggestion to time pulling down the archive and sending it to /dev/null. since you have enough memory. you could seperately time extracting it to ramfs. > Moreover, it is strange that Plan9 running under QEMU on 2.4Ghz/Core2 > Duo/2Gb RAM/250GiB SATA/IDE HDD machine out performs a natively > installed one. what is slower, exactly? - erik