In article , Mayayana
wrote:


| It's important for *any* file I/O. The massive gain is the lack of latency
| with all disk operations. Given that all applications touch a lot of files
| in their general operation every micro/milli-second gain adds up. It is
| genuinely transformative.
|

Yes, that's true. That's what Carlos was talking about
with his on-disk database work. But most people are
not doing massive file access. I open a file in a text editor
or graphic editor. Most of what's happening is in RAM until
I save to disk.

you're ignoring scratch files, log files, parts of the os, the app
itself and much more.

I load a webpage. It' save cache, etc, to
disk. Even on older disks, the speed of loading a file is
in the range of maybe 1 ms per MB. (I've tested it before
and don't remember exactly, but it's extremely fast.)

your numbers of 1ms per mb would be 1 second per gigabyte, which is not
only impossible for a hard drive but also not possible for the fastest
ssds (~300mbyte/s).

you're also ignoring hard drive seek time, which is a significant
overhead for smaller files as well as fragmented larger files.

seek time on an ssd is effectively zero. that alone is a benefit, even
without the faster i/o.

The point being that in the vast majority of things
that people do, an SSD offers no advantage. You're not
going to is a difference if MS Word is saving your DOC
to disk once every 5 minutes, spending 1 ms to do it
instead of 2 ms.

that is simply false.

replacing a hard drive with an ssd will result in a substantial overall
improvement in performance.

the difference might be a little less noticeable with ms word since the
limiting factor is the user typing, but that's not the only app people
use.