For D620 the max CPU to increase for replacement is T7600, which i had done it recently.
Talking on heat issue, T7600 runs cooler then T5500 (old CPU)... my current T7600 normal temp 30-35 degC whereas T5500 normally stay at 40-49degC, all these info was get from the iStat Menu.
Hey anyone can share if i can replace D620 with D630 heatsink? 'cause D630 comes with Northbridge and Southbridge too... i'm thinking making the laptop ever cooler.