Whats a good cpu cooler for AM4 on B450 M 2?

Solution
The board size doesnt matter. Any cooler will fit. What matters is the case you choose. Different cases can accommodate different size coolers. If you want to push the 2600 to around 4ghz or above, you will need one of the big juicy tower coolers like the Noctua NH-D14/D15/s, Cryorig R1, BeQuiet Dark Rock, etc.
And for those big coolers, you will need a mid tower or full tower case, depending on which one you choose.
The board size doesnt matter. Any cooler will fit. What matters is the case you choose. Different cases can accommodate different size coolers. If you want to push the 2600 to around 4ghz or above, you will need one of the big juicy tower coolers like the Noctua NH-D14/D15/s, Cryorig R1, BeQuiet Dark Rock, etc.
And for those big coolers, you will need a mid tower or full tower case, depending on which one you choose.
 
Solution

Are you sure the cooler wont block any of the ram slots? I understand that any cooler could fit and i already have a mid tower from corsair, but im just wondering if there are any known issues with the b450 and cpu cooler compatibility.
 
Depends on what kind of RAM you have. If you get low profile RAM like the Corsair LPX series, it will not be an issue. Also some of those coolers have the feature to push up the front fan slot to accommodate RAM with medium heat spreaders. If you get the tallest heat spreaders, that can be an issue.
 
Mobo's are all the same. There's a certain amount of real-estate surrounding the socket that's inviolate, no componentry at all. So ram sockets can only be so-close. They are also all the same, same dimensions. There are more than a few of the bigger towers that do infringe on the sockets, of those, mostly its just the fan overshadowing slot #1, leaving enough space for ram on dual channel in #2/#4. Many times it's simply a matter of using low profile or no top heatsink model ram.

So the B450 isn't any different than any other ATX mobo. If it has 4x slots, they'll all be roughly in the exact same spot.
 
noctua's site will show you which motherboards are compatible

thermalright has a little paper printout you can cutout and try it on your board

actually some some mobos have shorter distance from ram and first pcie slots to the cpu socket. so it depends on the mobo you get

generally, noctua D15S has better mobo compatibility than D15