On Thu, Oct 2, 2008 at 3:09 AM, Marc Bevand <[EMAIL PROTECTED]> wrote:
> Erik Trimble <Erik.Trimble <at> Sun.COM> writes:
>> Marc Bevand wrote:
>> > 7500rpm (SATA) drives clearly provide the best TB/$, throughput/$, IOPS/$.
>> > You can't argue against that. To paraphrase what was said earlier in this
>> > thread, to get the best IOPS out of $1000, spend your money on 10 7500rpm
>> > (SATA) drives instead of 3 or 4 15000rpm (SAS) drives. Similarly, for the
>> > best IOPS/RU, 15000rpm drives have the advantage. Etc.
>>
>> Be very careful about that. 73GB SAS drives aren't that expensive, so
>> you can get 6 x 73GB 15k SAS drives for the same amount as 11 x 250GB
>> SATA drives (per Sun list pricing for J4200 drives). SATA doesn't
>> always win the IOPS/$. Remember, a SAS drive can provide more than 2x
>> the number of IOPs a SATA drive can.
>
> Well let's look at a concrete example:
> - cheapest 15k SAS drive (73GB): $180 [1]
> - cheapest 7.2k SATA drive (160GB): $40 [2] (not counting a 80GB at $37)
> The SAS drive most likely offers 2x-3x the IOPS/$. Certainly not 180/40=4.5x
>
> [1] http://www.newegg.com/Product/Product.aspx?Item=N82E16822116057
> [2] http://www.newegg.com/Product/Product.aspx?Item=N82E16822136075
>
But Marc - that scenario is not realistic. Your budget drives won't
come with a 5 year warranty and the MTBF to go along with this
warranty. To level the playing field lets narrow it down to:
a) drives with a 5 year warranty
b) drives that are designed for continuous 7x24 operation
In the case of SATA drives, the Western Digital "RE" series and
Seagate "ES" immediately spring to mind. Another very interesting
SATA product is the WD Velociraptor - which blurs the line between 7k2
SATA and 15k RPM SAS drives.
For the application the OP talked about, I doubt that he is going to
run out and purchase low-cost drives that are more at home is a
low-end desktop than they are in a ZFS based filesystem.
Regards,
--
Al Hopper Logical Approach Inc,Plano,TX [EMAIL PROTECTED]
Voice: 972.379.2133 Timezone: US CDT
OpenSolaris Governing Board (OGB) Member - Apr 2005 to Mar 2007
http://www.opensolaris.org/os/community/ogb/ogb_2005-2007/
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