First things first, Do you need an SSD ? If you're reading this post I assume you've got one and the decision has already been made. If you don't have one the decision making criteria is a little different but equally simple. It's like the difference between a Ferrari and a Mondeo. If you like speed and are willing to pay for it then great, buy an SSD, otherwise for the same money you could buy 5+ Mondeo's.
Here is the the process I went through to migrate to a SSD on Windows 7
1.) Remove page file and hibernation file, remove as many documents and files as possible on to external storage and uninstall any programs you no longer need. Empty Recycle Bin.
2.) Disable system restore (again to save space)
2.) Defragment drive until no fragments remain (http://ultradefrag.sourceforge.net/en/index.html)
3.) Shrink Drive (as much as possible) in Windows 7 (My HDD was 500GB and the SSD was 120GB) until it will fit on the drive
4.) Using Clonezilla backup drive to external storage (you can skip to step 6 if you do a disk-disk copy with an external caddy). http://clonezilla.org/
5.) Install SSD
6.) Restore backup to SSD via network/USB/esata using clonezilla (Esata is the quickest, then USB, then network)
7.) Re-instate pagefile and hibernation (and system restore if you feel the need).
8.) Disable Defragmentation
9.) Disable file indexing
The above is fairly self explanatory with tutorials on the internet, but some useful tidbits are as follows:
Elevated command prompt
to run an elevated command prompt click on the start button, and in the search box type 'cmd' you then need to right click on the search result and select 'run as administrator'
in an elevated command prompt type 'powercfg /h off' without the quotation marks. use 'powercfg /h on' to turn this back on again.
Short stroking the drive
There is a train of thought that leaving unpartitioned space at the end of the SSD will prolong it's life. An SSD potentially has a shorter life span than a hard drive and this may be increased by 'short stroking' the drive. This means that the wear levelling algorithm used to ensure that the flash chips are used equally has a larger amount of space to do the levelling over. My opinion is that for the sake of 20gb of my 120gb drive I may as well do it.
Testing Performance: (winsat disk or dd)
Once you have done this process you can use the command 'winsat disk' to test the performance of your drive. Alternatively if you have a Linux installation (a wise move) you can run bonnie++, hdparm -T or use DD to give you a basic result.
reuse disk in external caddy
I can recommend the following item (£5.10 at time of post) as a caddy for the 2.5" drive that you have removed for re-use. I tried the cheaper ones and the build quality is dismal.
2-5-inch SATA USB e-SATA HDD Laptop Enclosure Caddy
performance results of 'winsat disk' for my Corsair Force3 SSD as follows:
Disk Sequential 64.0 Read 366.98 MB/s 7.9
Disk Random 16.0 Read 154.20 MB/s 7.5
Responsiveness: Average IO Rate 0.44 ms/IO 7.9
Responsiveness: Grouped IOs 6.68 units 7.7
Responsiveness: Long IOs 1.02 units 7.9
Responsiveness: Overall 6.79 units 7.9
Responsiveness: PenaltyFactor 0.0
Disk Sequential 64.0 Write 497.45 MB/s 7.9
Average Read Time with Sequential Writes 0.209 ms 7.9
Latency: 95th Percentile 0.616 ms 7.9
Latency: Maximum 39.874 ms 7.9
Average Read Time with Random Writes 0.133 ms 7.9
One large con of doing this change is that currently few, if any, SSD's implement power saving so do not expect your notebook/laptop battery to last ass long as it did before..