I had one of those IDE-to-SATA converters lying around in my drawer for some reason. I used it to throw a modern 500G SSD into my old P4:

I transferred my Debian install from the period 160G HDD onto the SSD drive and now it's nice and quiet, and quite a bit speedier than the original IDE HDD.
But I only use it with Linux because Windows XP doesn't have TRIM support and will kill the SSD in short order if I run it. Linux on the other hand... no problem, it's safe:
~$ lsblk --discard
NAME DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO
fd0 0 0B 0B 0
fd1 0 0B 0B 0
sda 0 512B 2G 0
├─sda1 0 512B 2G 0
├─sda2 0 512B 2G 0
└─sda3 0 512B 2G 0
sr0 0 0B 0B 0
sr1 0 0B 0B 0
(Non-zero DISC-GRAN and DISC-MAX values indicates TRIM support)
Another proof that Linux is just plain better 😉
The machine has been rocking this disk all day long without any problem. I recommend this little doodad.
The drive cost me a big fat nothing 🙂 I'm adding stuff to this machine only if it's free.
That's also why it has two DVD drives: one of them writes to DVD-RAM but has a dead CD laser, while the other still have CD support. But... both were free 🙂
It was just a general PSA.