ADDITIONAL COMMENTS: Current system is 2.2 gigahertz AMD Athlon 64 X2 Dual Core, 3328 Megabytes Usable Installed Memory, Nvidia GeForce 7600GS with outputs for the two monitors. System runs a little slow when Antivirus is updating in the background or many websites are open. Some spreadsheets have me drumming my fingers when saving, although not unbearable.
Basically I need advice on how to improve over what I am used to without overkill. Also, how can I identify the sort of hardware I need so I can continue to use the two monitors? Does overclocking pertain? Finally, are the DDR2 800Mhz Non-EDD memory modules I now own compatible/reusable in the Non-Gamer system?
I need knowledgeable advice and I appreciate your thoughts.
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It seems like you have a very (relatively) capable graphics card for the task at hand, which is compatible with the x16 Pci-e slot on the suggested motherboard. I would suggest that you would do a memory upgrade, however, based on what motherboard you are to use (note that your graphic's card will be compatible with 99% of all motherboards from 2 years back), it will require different RAM because the difference in sockets.
To clarify, you would be fine with the setup provided as the "Non-Gamer" system, however, as an Intel fanboy, I would suggest differently. If you have 650$, then I think that you should invest in something that will stand time's toll and being capable of handling up and coming Operating Systems (e.g. Windows 8 prob 2011 according to rumours).
E.g. a P55 or H55-motherboard, capable of the new i3-i5-series which has great performance in processing. From what you tell us it seems very much to be a processing/memory bottleneck. That's another reason why I suggest a modern motherboard, it supports new and surprisingly cheap memory modules ($100 = 4GB of 1333MHz DDR3-ram). Also, these new processors have quite a cache, which will improve your speed drastically.
Processing unit: any i3-i5 e.g. Intel Core™ i3 Dual Processor i3-530 Dual Core, 2.93Ghz, Socket 1156, 4MB, 73W, Boxed w/fan
Graphic's unit: Your 7600GS
Motherboard: e.g. ASUS P7H55-M PRO LGA 1156 Intel H55 HDMI Micro ATX Intel Motherboard
Memory: CORSAIR XMS3 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Dual Channel Kit Desktop Memory Model TW3X4G1333C9
This would cost $289 and would be blazing fast.
If you're not into it then I'm sure there's an AMD-fanboy around