Demonstration of my computer shut down and boot up with Seagate Momentus XT 500Gb hybrid SSD drive installed.
Computer is an HP Pavilion dv5 laptop, 4Gb RAM, with 2.53GHz Intel duo core CPU. It came with a 250Gb Hitachi Travelstar hard drive (5400rpm). I bought it in 12/2008 and it was fine for a few years, but cold start up times were starting to approach around 5 minutes. I cleared out bloatware and unused programs, defragged the hard drive, and ran a few utilities to try improving performance (Vistax64.com was a big help). While I did experience some gains, I wanted to improve it much more. The dv5 can take 8Gb of RAM, but I heard that wouldn't show much of an improvement unless I compile programs or do a lot of multitasking.
By far the biggest improvement you can introduce to an old laptop is a faster hard drive. SSD's (Solid State Drives) will make your computer fly compared to how it worked before. They are expensive, though. At $200 for a highly praised 256Gb SSD (Nov 2012), this is about $150 more than a conventional 250Gb hard drive. But there's a very cost effective alternative, that being SSD+HD (SSD hybrid).
I took this video after I installed the Seagate Momentus XT 500Gb, and I'm thrilled with the performance improvements. Going from around a 5 minute cold boot to just over 1 minute is phenomenal.
I should have mentioned that the hard disk inside the Momentus XT 500Gb spins at 7200rpm, so there's an inherent speed benefit over a 5400rpm HD. However, a faster spinning platter means more power is required. On battery power, I've lost about 20-30 minutes compared to the older drive. I don't travel much these days, so it's not a big deal. But it's something to keep in mind if you run your laptop on battery power fairly often. If you normally get 4-5 hours, it won't be that much of an impact though.
Sorry for the crappy video quality. I recorded this on an iPod Nano 5th Gen in dim light. Also, that "bleeping" sound that appears in the background is a defect that some Nano's suffer from (Apple was COMPLETELY USELESS in helping me with this).
UPDATE:
Having now owned this drive for about 6 months, I have noticed that the boot up time has slowed down somewhat. I've not taking any direct measurements, but it's not a significant change. I'm still satisfied with this drive.