Using dd to seek to random places in disk and reading I think I am getting ~60MB/sec which is more respectable. It varies a lot more if I only read ~200MB which is what hdparm seems to do.
net6501 ~ # time dd if=/dev/sdb bs=$((1024*1024)) seek=$((54565*1024*1024)) count=1024 of=/dev/null 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 17.9964 s, 59.7 MB/s real 0m18.011s user 0m0.008s sys 0m5.070s On Mon, Aug 13, 2012 at 12:44 PM, Nikhil Sethi (निखिल सेठी) <nik...@sethi.ws> wrote: > Yes. It does seem quite low, so I think I might have mis-configured > something. Would be nice to hear someone getting higher speeds. > > I noticed that if I run hdparm -t repeatedly, after the first run, I > start getting ~62MB/sec in subsequent runs. > > But if I run hdparm -tT repeatedly, then "buffered disk reads" does > not change much from run to run: > > net6501 ~ # hdparm -tT /dev/sdb > > /dev/sdb: > Timing cached reads: 866 MB in 2.00 seconds = 432.90 MB/sec > Timing buffered disk reads: 86 MB in 3.01 seconds = 28.62 MB/sec > net6501 ~ # hdparm -tT /dev/sdb > > /dev/sdb: > Timing cached reads: 868 MB in 2.00 seconds = 433.46 MB/sec > Timing buffered disk reads: 86 MB in 3.00 seconds = 28.62 MB/sec > net6501 ~ # hdparm -tT /dev/sdb > > /dev/sdb: > Timing cached reads: 864 MB in 2.00 seconds = 432.20 MB/sec > Timing buffered disk reads: 86 MB in 3.01 seconds = 28.53 MB/sec > net6501 ~ # hdparm -tT /dev/sdb > > /dev/sdb: > Timing cached reads: 866 MB in 2.00 seconds = 432.60 MB/sec > Timing buffered disk reads: 88 MB in 3.03 seconds = 29.05 MB/sec > net6501 ~ # hdparm -tT /dev/sdb > > /dev/sdb: > Timing cached reads: 870 MB in 2.00 seconds = 434.40 MB/sec > Timing buffered disk reads: 78 MB in 3.03 seconds = 25.78 MB/sec > > > net6501 ~ # hdparm -t /dev/sdb > > /dev/sdb: > Timing buffered disk reads: 42 MB in 3.01 seconds = 13.96 MB/sec > net6501 ~ # hdparm -t /dev/sdb > > /dev/sdb: > Timing buffered disk reads: 190 MB in 3.03 seconds = 62.76 MB/sec > net6501 ~ # hdparm -t /dev/sdb > > /dev/sdb: > Timing buffered disk reads: 188 MB in 3.01 seconds = 62.56 MB/sec > net6501 ~ # hdparm -t /dev/sdb > > /dev/sdb: > Timing buffered disk reads: 190 MB in 3.02 seconds = 62.82 MB/sec > net6501 ~ # hdparm -t /dev/sdb > > /dev/sdb: > Timing buffered disk reads: 188 MB in 3.03 seconds = 62.05 MB/sec > > > On Sun, Aug 12, 2012 at 5:08 PM, Rune Petersen <r...@megahurts.dk> wrote: >> On 10/08/12 22:57, Nikhil Sethi (निखिल सेठी) wrote: >>> >>> I am wondering what kind of disk speed to expect on net6501. >>> >>> I get pretty low from non-ssd disk and I think I might have the kernel >>> mis-configured. >>> >>> sda is a mini-pcie ssd, sdb is 2.5" 5400 RPM SATA. >>> >>> net6501 ~ # uname -a >>> Linux net6501 3.5.1-net6501-1 #7 SMP Thu Aug 9 23:37:33 PDT 2012 >>> x86_64 Genuine Intel(R) CPU @ 1.00GHz GenuineIntel GNU/Linux >>> >>> net6501 ~ # hdparm -tT /dev/sdb >>> >>> /dev/sdb: >>> Timing cached reads: 864 MB in 2.00 seconds = 432.14 MB/sec >>> Timing buffered disk reads: 80 MB in 3.03 seconds = 26.42 MB/sec >>> >>> net6501 ~ # hdparm -tT /dev/sda >>> >>> /dev/sda: >>> Timing cached reads: 866 MB in 2.00 seconds = 432.38 MB/sec >>> Timing buffered disk reads: 362 MB in 3.00 seconds = 120.50 MB/sec >>> >> >> >> I have no experience with net6501, but I find 26MB/s very slow and >> disappointing. the net5501 was slightly slower. >> >> in general 5400 RPM HDD's are not that slow. for reference I have some >> numbers for a 2.5" 5400 RPM drive - WDC WD10JPVT running SATA1(forced)+AHCI >> >> /dev/sda: >> Timing cached reads: 638 MB in 2.00 seconds = 319.16 MB/sec >> Timing buffered disk reads: 246 MB in 3.02 seconds = 81.48 MB/sec >> >> The system has lower CPU and memory bandwidth, so I would expect the net6501 >> to be equal or better in performance. >> >> >> Rune Petersen _______________________________________________ Soekris-tech mailing list Soekris-tech@lists.soekris.com http://lists.soekris.com/mailman/listinfo/soekris-tech
