grab CPUZ, and install it and run it. go to the main board tab, and get the :
from that we can be very precise on the ram and possible cpu upgrades.
Also, what programs are you using for engineering? do they support 64bit OS's ? your apps will be able to address more ram in a 64bit environment and will swap space a little less.
after ram, the big limiter will be the cpu. the pentium-d series while decent for its time but now is a really poorly bonded pair of old style p'4s. i know you are not looking at spending alot, but consider that a cheap amd-quad or a slightly more intel quad with integrated grapgics would not run more then 300-400$. but if your looking to keep the cost too 200$ or less then the memory and a possible SSD may be better.
on the SSD, keep in mind a lot of large photo's will be swapped to the drive unless you running 64bit and 6+ gigs of ram. so another method of speeding up photo work would be to drop a 64-80gig SSD in and map the photoshop temp files and work space to the ssd.... i'd also move the windows temp file and your user temp files as well... you would see a huge I/O improvement...
so i guess i should ask this... how much are you spending ? is there a limit?
if you could... i would do both. move to 4 gigs ram, and also add a crucial, corsair or intel SSD.
<font color="#FF0000"> Cybert said: Capitlization and periods are hard for you, aren't they? I've given over $100 to techforums. I should have you banned for my money.</font>