L2 Cache?

All right, one last question before I make the plunge into buying.

I'm debating between two used iMacs right now. One is the mid-2007 model, but with upgraded ram to 4gigs. The other is the early-2008 model with the same ram upgrade. The only other difference is harddrive size - the former being 320gb, the latter 250gb.

The only OTHER difference I see is in the L2 cache - the mid-2007 model is 4mb shared and the early-2008 model is 6mb shared... also there is a difference in frontside bus - 800mhz and 1066mhz respectively.

The most intensive program I will be using is Adobe Photoshop. No gaming. Will the difference in the 2008 model be noticable?