It has been a long time since lapping was a requirement to get the best cooling for your new processor, however it might be making a comeback.  Threadripper is endowed with a larger heatsink than your average CPU and to help you accommodate that the chip contains an Asetek mounting bracket which is compatible with most AiO coolers.  The bracket and size of the heatspreader do seem to exacerbate any curvature of the coldplate however, the Asetek AiO which [H]ard|OCP tested needed to be lapped for a proper mating.

Since they had some difficulty with AiO coolers, [H] decided to configure their own watercooler for Threadripper.  They grabbed an old Koolance water block they had handy and with a bit of time and a $10 trip to a hardware store they ended up with a much better solution.  Take peek at the process, especially if you happen to have parts lying around that you want to put back to use. 

"What do you do when you don't have the proper parts that you need to water cool your new thread ripper? Make you own with trash you find around the house. Maybe even repurpose and old water block that is in your closet."

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Processors