I currently have a 7200 rpm hard drive, 6gb of ram, and an i7-740qm cpu. My question is, which would improve the performance of my laptop more, upgrading to an ssd, or adding 2gb of ram to be used as a ramdisk? The ramdisk would be cheaper and faster, but 2gb isn't going to hold the whole os, just key programs.
A ramdisk will definitely perform much better than a solid state drive. In fact a ramdisk will smoke a ssd. Ramdisk benchmarks are insane. Unfortunately there are enormous problems. First, as you already know the amount of ram available for a ramdisk is severely limited - big time in a typical user's system. Second, the amount of memory allocated to the ramdisk is no longer available to Windows. That might hamper Windows performance. Third, when you are finished you lose all data in the ramdisk. You'd have to set up automatic backup and redirect files.
If you want to experiment and see what its like, then try the freebie:
I have used a ramdisk before, and I had no problems backing it up, and I am certain that I do not need the 2gb ram to be used as normal ram. So, would an ssd still improve overall performance more than placing just the programs I use most on a ramdisk and running the os of a 7200 rpm drive?
The first time you start your machine it still has to read everything from the mechanical hard drive to put it into the ram disk. Subsequent accesses to those programs will see the benefits of the faster ram disk. It just depends on how frequently you need to access the stuff that is in the ram disk. Everybody's situation will be a little bit different.
My machine with 32 bit windows does a lot of paging, and reading and re-reading DLL's from the hard drive. A ram disk would not help me because it would reduce my available memory and make it page to the hard drive even more. I would have to go to a 64 bit OS and add a bunch of ram to get things to work, and I have too many apps that won't work under a 64-bit OS to make that worthwhile.
http://www.romexsoftware.com/en-us/primo-ramdisk/index.... <--- That is my ten cents. It takes all the hassles of a Ramdisk away, auto backups your files and everything. Best solution I've found by far. THIS is better than an SSD, I use it myself. Fantastic idea honestly, especially those who cannot afford a SSD.