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Old 16th September 2010
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Carpetsmoker Carpetsmoker is offline
Real Name: Martin
Tcpdump Spy
 
Join Date: Apr 2008
Location: Netherlands
Posts: 2,243
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So I got some new disks:

Code:
[~]# dmesg | grep ^ad
ad0: 3811MB <CF CARD 4GB Ver3.06K> at ata0-master UDMA100
ad1: 1943MB <TRANSCEND 20100323> at ata0-slave UDMA66
ad6: 1430799MB <WDC WD15EADS-00S2B0 01.00A01> at ata3-master UDMA100 SATA 3Gb/s
ad10: 1430799MB <WDC WD15EADS-00S2B0 01.00A01> at ata5-master UDMA100 SATA 3Gb/s
Code:
[~]# diskinfo -c -t /dev/mirror/newdatad 
/dev/mirror/newdatad
        512             # sectorsize
        10737418240     # mediasize in bytes (10G)
        20971520        # mediasize in sectors
        0               # stripesize
        8192            # stripeoffset
        1305            # Cylinders according to firmware.
        255             # Heads according to firmware.
        63              # Sectors according to firmware.

I/O command overhead:
        time to read 10MB block      0.097558 sec       =    0.005 msec/sector
        time to read 20480 sectors   3.493613 sec       =    0.171 msec/sector
        calculated command overhead                     =    0.166 msec/sector

Seek times:
        Full stroke:      250 iter in   1.851474 sec =    7.406 msec
        Half stroke:      250 iter in   1.967489 sec =    7.870 msec
        Quarter stroke:   500 iter in   3.482903 sec =    6.966 msec
        Short forward:    400 iter in   2.997552 sec =    7.494 msec
        Short backward:   400 iter in   3.032469 sec =    7.581 msec
        Seq outer:       2048 iter in   0.392586 sec =    0.192 msec
        Seq inner:       2048 iter in   0.393736 sec =    0.192 msec
Transfer rates:
        outside:       102400 kbytes in   0.977659 sec =   104740 kbytes/sec
        middle:        102400 kbytes in   1.071896 sec =    95532 kbytes/sec
        inside:        102400 kbytes in   0.996447 sec =   102765 kbytes/sec
For comparison, here are two WD 500GB RE3 disks in the same system:
http://www.daemonforums.org/showpost...6&postcount=37

Transfer rates are faster, but seek times are slower. Actually, performance isn't that bad for the GP disks,
The GP disks are a *lot* quieter too. I had the 500GB disks in a "silent hard drive enclosure", which helped a bit with the noise, but the GP disks made *significantly* less noise without enclose than the RE disks inside the enclosure! (My system is now inaudible at ~75cm).

ad0 and ad1 are CF cards with a CF -> ATA converter I got off ebay for 90 cents.
The Transcend is a 300x card, the kingston is a cheap one I had lying around.

Diskinfo won't run on them ( diskinfo: read error or disk too small for test.: Input/output error), but here's what dd says:

This is the Transcend:
Code:
[~]# dd if=/dev/zero of=/TEST bs=1M count=100                                                                                                                    glitch:1:33
100+0 records in
100+0 records out
104857600 bytes transferred in 4.592359 secs (22833058 bytes/sec)
The Kingston:
Code:
[~]# dd if=/dev/zero of=/var/tmp/TEST bs=1M count=100
100+0 records in
100+0 records out
104857600 bytes transferred in 19.193520 secs (5463177 bytes/sec)
300x is supposed to be 40MB/s ... meh, not even close ... Still a lot faster than the Kingston ...
I got the kingston after some experiences with the ssd in my laptop, I have a memoryfs for /var/ and /tmp/, which works OK, but sometimes I ran into problems and some tweaking is required ... I got the kingston for /var/ and avoid all of that.

In hindsight, it might have been a better idea to get the 4GB Transcend (... But that one was 15 euros more expensive ).
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