[ltp] Re: solid state drive?

[km]

On 16/02, Micha Feigin wrote:
> > 
> > The wins on the other hand is:
> >  - speed (my x300 boots XP to desktop in 7 seconds and ubuntu in 15)
> >  - robustness (no moving parts)
> >  - sound (no moving parts)
> > 
> 
> Yes, but AFAIK write is a lot slower than standard disk
> 

Depends on the SSD. Slow writes are usually a characteristic of MLC drives,
though different SSDs have hugely varied performance.

The Samsung SLC drive in the x300 performs something like this with
sequential writes:

OS	Filesystem/driver	peak	sustained
-------------------------------------------------
WinXP	NTFS 4k cluster		90mb/s	65mb/s
WinXP	Ext3 ext2fsd driver	60mb/s	25-40mb/s	fluctuates _alot_
Linux	NTFS fuse		50mb/s	35mb/s
Linux	Ext3 4k block		90mb/s	65mb/s

Clearly better than a hard drive.

This was tested with dd with a block size of 1MB and 3GB of /dev/zero.

FS type and OS looks pretty irrelevant when doing sequential I/O, atleast
for native filesystems.

Worth noting is that actual write speeds seem to go down when the filesystem
gets fragmented or is near its capacity.

And for interactive purposes (ie the responsiveness when using your
computer) the access time is usually the most important part and atleast
with this SSD it's so low that I dont notice the disk at all :)

-km