Frank Cusack wrote:
On May 31, 2007 1:59:04 PM -0700 Richard Elling <[EMAIL PROTECTED]>
wrote:
CF cards aren't generally very fast, so the solid state disk vendors are
putting them into hard disk form factors with SAS/SATA interfaces. These
If CF cards aren't fast, how will putting them into a different form
factor make them faster?
Semiconductor memories are accessed in parallel. Spinning disks are accessed
serially. Let's take a look at a few examples and see what this looks like...
Disk iops bw atime MTBF UER endurance
----------------------------------------------------------------------------------
SanDisk 32 GByte 2.5" SATA 7,450 67 0.11 2,000,000 10^-20 ?
SiliconSystems 8 GByte CF 500 8 2 4,000,000 10^-14
>2,000,000
SanDisk 8 GByte CF ? 40 ? ? ? ?
Seagate 146 GByte 2.5" SATA 141 41-63 4.1+ 1,400,000 10^-15 -
Hitachi 500 GByte 3.5" SATA 79 31-65 8.5+ 1,000,000 10^-14 -
iops = small, random read iops (I/O operations per second) [higher is better]
bw = sustained media read bandwidth (MBytes/s) [higher is better]
atime = access time (milliseconds) [lower is better]
MTBF = mean time between failures (hours) [higher is better]
UER = unrecoverable read error rate (errors/bits read) [lower is better]
endurance = single block rewrite count [higher is better]
http://www.sandisk.com/Assets/File/pdf/oem/SanDisk_SSD_SATA_5000_2.5_DS_P03_DS.pdf
http://www.storagesearch.com/ssd-16.html
http://www.hitachigst.com/portal/site/en/menuitem.eb9838d4792cb564c0f85074eac4f0a0
http://www.seagate.com/docs/pdf/datasheet/disc/ds_savvio_10k_2.pdf
It is a little bit frustrating that all vendors have different amounts of data
available on their product which is publically available :-(.
-- richard
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