I just upgraded my 3-year old laptop at work. The laptop had a quite slow 4,500 p.m. 1.8", 80GB hard drive. Compounding the performance was that the entire drive was encrypted. It took quite a long time for the laptop to hibernate and either wake up from hibernation or perform a complete reboot (both were measured in 10's of minutes).
The new laptop has a nice 250GB, 2.5" SATA II (3.0 Gbps), 7,200 rpm drive. Lots of capacity and lots more performance. However, the drive is still encrypted. The performance is much better than before, but I still find myself wanting more (sue me--I'm a speed junkie). So a colleague suggested that I install an SSD.
I bought an SSD (OCZ Vertex 2, 120GB, SATA II) and installed it. I didn't have to copy over the data from the old hard drive since I had an installation disk for new laptops. I just popped the drive in the laptop, installed Windows 7 (the new OS for the laptop). Of course, during the installation, the drive was encrypted.
The performance is just amazing! I can boot from scratch in seconds (less than a minute). I can restart from hibernation in seconds and I can hibernate in seconds. I didn't think switching to an SSD in the laptop would make such a difference, but I think the encryption of the entire drive really penalizes the performance of a spinning disk and the SSD is capable of much better response. In particular, the SandForce based SSD has very good random write and random read IOPS performance--most likely to be a limiting factor for an encrypted drive.
Color me happy!