I have found that small CPU heatsink fans are unbearably noisey, as are those teeny little graphics card fans.
Personally I use Zalman Super Flower Coolers (for both Pentium and AMD CPUs.)
Both the 92mm and 120mm fan versions run totally silent on my AMD pcs.
Get them and all the relevant info from the Quiet PC guys:
I'm sorry but I don't know anything about Intel Pentiums ( always use AMD ).
You'll have to measure the space around your CPU socket on the motherboard if it's not on the motherboard compatibility list.
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