The i3 isn't that bad. I actually have one right now. Probably around black friday I'll go check Microcenter for an 875k myself. That's like twice the processor. 
That's a core2duo/quad board. Unfortunately it requires DDR2 ram and 1156 needs DDR3 - so you're going to need to buy ram if your going to upgrade. What's your current processor?
This is the best possible processor you can get.
Newegg.com - Intel Core 2 Quad Q9650 Yorkfield 3.0GHz 12MB L2 Cache LGA 775 95W Quad-Core Desktop Processor BX80569Q9650

That's a core2duo/quad board. Unfortunately it requires DDR2 ram and 1156 needs DDR3 - so you're going to need to buy ram if your going to upgrade. What's your current processor?
This is the best possible processor you can get.
Newegg.com - Intel Core 2 Quad Q9650 Yorkfield 3.0GHz 12MB L2 Cache LGA 775 95W Quad-Core Desktop Processor BX80569Q9650






