Have a Samsung 840 SSD in a Thinkpad R60i running Xubuntu 13.04 /w 3GB usable RAM. Provisioned it with 20% free space and enabled TRIM, and it was fast as greased lightning to start, but four months later it takes three times longer to boot. Only down to 30% free in my ext3 file system and only installed 500MB of apps since install.
I have seen Slow Samsung 830 SSD! and did update the firmware before install.
Took the opportunity to backup, and reinstall with Xubuntu 13.10. Also applied the solution I found today at http://www.pcworld.com/article/2088341/how-to-restore-your-ssd-to-peak-performance.html -
Booted from a flashdrive on which I had installed a bootable ISO of PartedMagic and started the app.
From System Tools, chose Erase Disk in the following menu
Chose Internal: Secure Erase then Continue
Picked the SSD then OK
When asked to do Enhanced Secure Erase, told it No.
Now, the reformatted system, with 13.10 and the same apps and data files as before loaded back on, boots faster than before and runs very nicely.