My system crashes if I pull the heatsink and rigged 40MM off my PLL chip.
In extreme overclocking, example: my 520FSB, the PLL heatsink has become a nessecity.
So yes they CAN help quite a bit, I wasnt able to pass 480FSB
before putting heatsinks on every friggin chip on my board.
As for
RAM sinks in paticular, my mushkin heatspreaders are quite hot with the 67MHz DDR overclock they are running.
So, unless you've hit a wall overclocking your
RAM, or probe readouts are showing it quite hot, there is no reason to get
RAM sinks.