On Wed 12 Mar 2014 09:37:19 AM Bob Bishop wrote: > Hi, > > If your software doesn't support TRIM then SSD write performance (and read, > to a lesser extent) will start to suck once the disk has had a certain > amount of use. Don't know if this applies in your case.
SSDs are rather decent about managing themselves these days. But I got the same meager write performance with my 6501-50 on a fresh Crucial M4 mSATA SSD that should be capable of 240MB/s. I'm tentatively blaming the sata controller built into the chipset, or possibly the SoC firmware not initializing things correctly. Or maybe, the platform as it is wired up, just doesn't have the bandwidth for decent speeds off the mSATA ports? > On 11 Mar 2014, at 10:32, Karsten Kruse <[email protected]> wrote: > > Ahoi, > > > > i have a bunch of net6501-70 for evaluation and they show poor I/O > > performance. > > > > I use CentOS 6.5 with kernel 2.6.32-431.5.1.el6.x86_64 and this is my > > disk: > > > > > > [root@sonde04 ~]# hdparm -i /dev/sda > > > > /dev/sda: > > > > Model=Samsung SSD 840 EVO 120GB, FwRev=EXT0BB0Q, SerialNo=S1D5NSADB40689E > > Config={ Fixed } > > RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0 > > BuffType=unknown, BuffSize=unknown, MaxMultSect=16, MultSect=16 > > CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=234441648 > > IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} > > PIO modes: pio0 pio1 pio2 pio3 pio4 > > DMA modes: mdma0 mdma1 mdma2 > > UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6 > > AdvancedPM=no WriteCache=enabled > > Drive conforms to: unknown: ATA/ATAPI-2,3,4,5,6,7 > > > > * signifies the current active mode > > > > > > Looks good to me, UDMA6 is used. This doesn't look as good: > > > > > > [root@sonde04 ~]# time dd if=/dev/sda of=/dev/null bs=1M count=1024 > > 1024+0 Datensätze ein > > 1024+0 Datensätze aus > > 1073741824 Bytes (1,1 GB) kopiert, 14,0558 s, 76,4 MB/s > > > > > > So this is read, this is what write looks like: > > > > > > [root@sonde04 ~]# sync ; time { dd if=/dev/zero of=/tmp/test.dd bs=1M > > count=1024 ; sync ; } > > 1024+0 Datensätze ein > > 1024+0 Datensätze aus > > 1073741824 Bytes (1,1 GB) kopiert, 47,0048 s, 22,8 MB/s > > > > real 0m50.428s > > user 0m0.022s > > sys 0m7.021s > > > > > > This is 1 GB (power of 2) written in 50 seconds, so that amounts to > > about 20,5 MB/s. Would anyone be so kind and run the commands himself, > > maybe with Debian or something with a more recent kernel. > > > > Also i would appreciate any tips on how to get a bit more write > > performance. We would like to monitor traffic with it, using NtopNG and > > tcpdump. When we dump traffic, we don't write payloads, just headers, so > > we don't need more than maybe 40 MB/s guess. > > > > > > Have a nice day, > > > > Karsten Kruse > > -- > Bob Bishop > [email protected] > > > > > _______________________________________________ > Soekris-tech mailing list > [email protected] > http://lists.soekris.com/mailman/listinfo/soekris-tech -- Thomas Fjellstrom [email protected] _______________________________________________ Soekris-tech mailing list [email protected] http://lists.soekris.com/mailman/listinfo/soekris-tech
