[BBLISA] SSD's - really any better performance?

[Mike Sprague]

Edward Ned Harvey wrote:
> Today I poked around looking at specs of SSD’s and 7.2krpm SATA hard 
> disks.  I just sampled a bunch of whitepapers on various drives and 
> averaged the results together.  Also, when there wasn’t an 
> apples-to-apples measurement to compare, I had to calculate, as 
> evidenced by the IOPS versus avg seek time.
> 
>  
> 
> The comparisons were pretty surprising, to me –
> 
>  
> 
> Sustainable reads:  SSD somewhat faster (avg 199MB/s compared to avg 126 
> MB/s)
> 
> Sustainable writes:  SSD equal to SATA (avg 124MB/s compared to avg 126 
> MB/s)
> 
> MTBF:  SSD equal to SATA.  1.17 vs 1.20 million hours
> 
> Read latency:  SSD way faster (0.16ms vs 8.5ms)  (which I derived from 
> 6300 IOPS and 8.5ms avg seek time)
> 
> Write latency:  SSD somewhat slower (12ms vs 8.5ms)  (which I derived 
> from 84 IOPS and 8.5ms avg seek time)
> 
>  
> 
> Actually, I’m not sure how fair the MTBF is.  Because a SATA drive will 
> eventually fail just from being powered on, while the life of a SSD is 
> basically determined by how much you write to it.

That is really interesting, thanks for posting the numbers.

We have been experimenting with ssd's for mysql servers.  Though I don't 
have hard numbers yet, the performance difference has been night and day 
(vs SAS).  So far, I am very  happy with the performance but I am still 
concerned on MTBF.  Like you say, it's different than 'regular' drives 
and I don't know anyone with personal, long term experience with ssd's.

thanks,
M

-- 
Michael Sprague
mfs at komerex.com