Hello,
As promised we have tested 3 Gb (aka SATA II) disks.
Configuration: LSI SAS3442X controller, Promise SAS JBOD, 12 disks
Seagate SATA 80 GB
Tested with parallel dd invocations with bs=32k.
The results look better:
# disks Read AVG Write AVG
1 69 69,0 68 68,0
6 420 70,0 324 54,0
7 459 65,6 367 52,4
8 426 53,3 394 49,3
9 399 44,3 389 43,2
10 410 41,0 431 43,1
11 438 39,8 428 38,9
12 468 39,0 481 40,1
Available bandwidth is 4 * 3 Gb = 1.5 GB (4 lanes / external wide SAS
port).
So there is still some room for improvement. Has anyone else a similar
setup and can provide results?
Maybe with the Adaptec SAS controller?
Thanks,
Mirko
Jeff Garzik schrieb:
Douglas Gilbert wrote:
If the SATA disk does 3 Gb/sec then yes but SATA-1 disks
run at 1.5 Gb/sec (and don't have NCQ). When a SAS HBA
To further confuse things, "SATA-1", "SATA-2", etc. don't mean much at
all. I recommend never using these terms.
There are many disks that can do NCQ but not 3 Gb/sec, for example.
Its best just to mention the existence of features, because there is
no __technical__ definition of "SATA 2" that one can test in software.
SATA 2 is just a set of features defined by marketing.
Jeff
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