> My Dell Inspiron E1505 shipped in 2007 with a 32-bit Core Duo > T2250 processor. In 2016, I STFW and saw that certain 64-bit Core 2 Duo > processors sometimes worked in this laptop (depending upon motherboard > hardware revision?). I bought and installed a T7400, and it works!
Same here: I upgraded to Core 2 Duo a mac mini and a Thinkpad T60, both of which came with a Core Duo. There's a noticeable performance increase and a slight improvement in power consumption as well. I recently decommissioned the mac mini, but I still use my T60 as backup laptop for when my T61 breaks down (such as right now, since one of the hinges died again). The 3GB limit on the RAM is becoming problematic, tho. Stefan