Thanks for fast and best reply
I will try to assemble accordingly
as your best information howmany time could it take for ROI Ie. Todays price of Bitcoin is 700$
You should not use this rig to mine BTC directly. That would take a long time (decades, I think), with the rising difficulty.
You should be mining scrypt based coins like LTC or others.
Take a look at any of the following links. Enter 2100 kHashes/sec in the scrypt textboxes, and they will give you an upper estimate of your earnings.
http://coinwarz.comhttp://dustcoin.comhttp://wheretomine.com/http://coinchoose.com/The value of these alt coins can be very volatile, so you may want to get familiar with these tables, and switching between coins when it increases your profitability. If you don't want to handle that manually, you can look into an auto-switching pool like
http://middlecoin.com