The XT Nitro+ Sapphire state 16
link, see TPU review (W1zzard has count on VRAM wrong 2+1 not 3+1),
link. GPU 10+3 VRAM 2+1 =16 phases.
Pulse drops 2,
link. Pure drops 2,
link. Pure is not 14 and Pulse is not 12, both are same,
link.
Currently there are only 2 types of VRM "makeup" I have seen so far on XT.
Higher phase count, greater power handling capability.
Higher phase count, may result in cleaner power delivery as more components.
Higher phase count, just due to extra components used, the power is spread through more components, may result in cooler running VRM.
Monolithic MPS MP87993 DrMOS apparently 90A used on XT Nitro+, so you have quite a lot there. Most use that mosfet, as the controllers for VRM are Monolithic Power Systems MP2868A.
Some I have seen use same controller, but slightly differing mosfet from Monolithic, perhaps older version of mosfet, one card a non XT I think had 50A IIRC.