I have a chance to upgrade the cpu on my internet surfer computer in the basement. I'm currently running a 520 2.8GHz with 2 x 512MB @ DDR400 2-3-3-6 and seems kind of sluggish running XP. The two of these are going for the same price (very cheap, really), and I can justify spending on an upgrade. To refresh your memories: P4 650 - 3.4GHz 2MB L2 800FSB 65nm (Cedar Mill?) P4 560 - 3.6GHz 1MB L2 800FSB 90nm (Prescott, oooh baby!) My board is an ASUS P5GD1-VM, so I won't/can't be overclocking. I want to know if there is tangible difference going with +200MHz or +1MB L2. Any recommendations?