Partitioning between SDD and HDD

[Paweł Brodacki]

2012/12/21 Javier Perez <pepebuho at gmail.com>:
> Hi, Roberto, I understand your point. One is more likely to be shuffling
> data than programs, therefore it is better to put the data on the faster
> storage medium.
> But the way I understand it, there is a limited number of times that one can
> write to a SSD due to the intrinsic nature of the media. Therefore I would
> not like to put write intensive files like data, caches, etc on this drive.
>
> Makes sense?
>
> Javier
>
Well, both yes, and no.

There is a limit to how much data you can write to a SSD drive, so it
is reasonable to reduce number of writes (e.g. mounting /tmp on tmpfs
which is coming to Fedora helps).

On the other hand current drives are designed to last several years
under heavy load, e.g. Intel's SSD 330 is rated for 3 years of 20GB
writes per day. I'd suggest you read warranty terms of drives you are
interested in. If you find a drive that is covered by 3 or 5 year
warranty under 15 GB/day it will last you a long time, and if it
won't, you'll get a replacement from the vendor.

As for the data placement scheme, what will be best for you depends
heavily on how you expect to use the system. If I were to build a
hybrid (SSD/HDD) system, I would put most of my /home on SSD, I would
be strongly tempted to put the system on SSD too, and relegate HDD to
storing media files (I do not edit audio/video, I listen to some
music, and HDD is more than adequate for that), .iso images and
virtual machine images (because SSDs are too expensive for me for bulk
storage).

If you are going to shell out for an SSD, then it's worth to put it,
where it will make the biggest difference, i.e. where there are many
random accesses, which kill HDDs. This means the documents you edit
and the binaries you start, in this order. If you spend 15% of the
system price on a part, that will give you 10-fold speed-up of a task,
that constitutes 5% of the time you wait for the computer, you will
not notice it much. If it gives you 10-fild speed-up of a task that
constitutes 70% of the time you spend waiting for the computer, you'll
notice where did your money go ;).

Paweł