Well basically I want to move off this crappy board and get DDR3 RAM, hopefully with 1600mhz or more clock speed and more memory.
However, I'm curious to know what the differences are, surely companies didn't just upgrade clock speeds for the fun, there must be some notable increase in performance, right?
at the moment I rarely hit the 2GB mark limit in task manager, I play a lot of games that are rendering intensive(if that's a real thing), basically games like Arma 2 and GTA IV render new objects constantly, so will upgrading from 333mhz DDR2 to DDR3 1000+ Mhz have any increase in performance(in terms of FPS), or will it just mean opening photoshop faster... or what?
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However one thing I do want to add, just merely having a DDR3 based system would provide plenty of bandwidth for whatever your doing.
The differences between 1333Mhz and 1866Mhz RAM would be very minimal (around 5%). So the higher speeds of DDR3 don't necessarily benefit the platform. I would say the CPU is a more important factor (with a minnimum amount of RAM, say 4GB), and next would be the GPU.
What is important with RAM is CAS timings. Normally you want to go for RAM with timings of 9-9-9-9 or something similar. CAS timings are basically the amount of time it takes your RAM to communicate with your CPU.
I've just touched the very basics of RAM, which you can get much more info. from reading articles like the one I provided.
No problem. If you do decide to get a new platform - you don't have to spend too much money on the DDR3 RAM, besides the amount you want (for example you want 8GB).
1333Mhz 8GB of RAM would be plenty fine over 1866Mhz 8GB of RAM. There would be practically 0 difference in your own eyes. The only way you would be able to tell the differences between different clocked RAM sets would be to run benchmarks.
The only exception to this would be AMD's APU's which use the DDR3 RAM as its video memory, where the extra bandwidth would help out with the graphics side.