

The SSD Improv - pieter
http://anandtech.com/storage/showdoc.aspx?i=3667

======
ghoerz
Full print-view article: <http://anandtech.com/printarticle.aspx?i=3667>

------
spudlyo
Another well written and researched piece of tech journalism from Anand Lal
Shimpi. Good to know the strengths and weaknesses of the Indilinx products.
Considering how hard it is to get your hands on an 80G X25-M, I might have to
start looking at OCZ or SuperTalent products.

------
spicyj
The 40GB Kingston drive looks promising. I'm hoping that the larger capacity
Intel drives will drop in price as well.

~~~
pmjordan
Indeed. I think I'll pick one up when it gains TRIM so I can add support that
feature in the SSD-as-HDD-cache driver I'm working on. Most of the other
smaller SSDs have terrible controllers. Too bad Intel aren't releasing a TRIM-
capable firmware for the previous generation of SSDs. (I have the 80GB version
of it)

~~~
aaronblohowiak
Pardon my ignorance, but can't you just increase the size of the pagefile to
consume the ssd and then increase the disk cache? this way the OS can handle
memory management as it pleases..

~~~
wmf
Most OSes don't swap their disk cache, since they assume that reading a page
from swap is no faster than reading it from the filesystem.

~~~
pmjordan
Correct. Moreover, disk caches in memory don't persist across reboots, which
means the first access since OS startup is ALWAYS slow. You also can't return
from an fsync() if writes have only been written to non-persistent cache. A
persistent cache therefore can help even if you have oodles of RAM. Moreso if
you don't.

------
Freaky
Hope we're going to see TRIM support on the X25-M G1's. Mine's already showing
signs of degraded performance :/

~~~
pmjordan
The poor man's TRIM is to copy the entire disk's data elsewhere, do an _ATA
Secure Erase_ operation on the SSD, then repartition, format, and copy
everything back. No chance of doing it online though.

------
zain
Does anyone know if Snow Leopard will ever support TRIM? It saddens me that I
have to boot into Windows 7 to manually run TRIM on my drive every so often.

~~~
tedunangst
How in the world does Windows know what blocks were used by files that you
then deleted in OS X?

~~~
zain
You're right. It appears I'm mistaken. I assumed it was more of an issue of
cleanup, but it's pretty obvious that running the TRIM utility in Win7 is
useless for my Mac partition.

Nonetheless, the question in my post was more of the point. I wish Snow
Leopard had TRIM support.

~~~
tedunangst
Yeah, if cleaning up were as simple as that, you wouldn't even need OS
support, the drive could just trim itself as it went. But it's been 20 years
since anybody designed disk geometry into a filesystem, and while TRIM may not
be as complicated as all that, it still requires more bookkeeping than the OS
usually does.

Optimally using TRIM, such that the OS will defragment the 512K blocks online
instead of reusing them, is even more work, and I'm not sure that's what
Windows is doing. They're just issuing TRIM opportunistically, AFAIK.

