Posted 19 November 2011 - 03:20 PM
I have to agree with dpunisher but with adding the following recent-events caveat:
Given the flooding in Thailand recently, hard drive prices have spiked upwards, where a 1 TB hard drive once cost $55-$65 it now costs $165.
An SSD for your boot drive would be your best bet, SSDs are still, at this time, extremely unreliable and likely to fail at the drop of a hat, so definitely pay attention to reliability - speed will already have come, in that you'll see increases in read/write from your platter hard disk of roughly 2x to 3x speed, so a little more isn't really worth the added headache of regular RMAs (having had to RMA 16 different SSDs of various make and model for a number of clients, I can tell you the "extra speed" is not worth it).
As far as RAM increases, his RAM increase suggestion is the best. While you'll not see a huge increase in performance immediately, the best performance increase will be to use about 1/4 to 1/3 of that as a RAMDrive and use it as the scratch or workspace for major development software, like Photoshop, or 3D modeling software.
If you really want a good speed boost, load or copy the installed files for a game to the RAM Drive and watch the load speed skyrocket. Don't do an install to a RAM Drive as that will REALLY hose up Windows' registry. This is best for games where moving the files can be done without too much damage to them.
To be honest, you are, as dpunisher said, at your plateau. Unless you find that applications are slowing down because they're pulling massive amounts of memory (CS5.1 anyone?) the increased cost of what you're looking for may not be immediately translated into performance increases, but will instead provide future-proofing.