[Tfug] Interchangeability of VRM's?

[Bexley Hall]

Hi,

I don't do hardware designs for the sorts of processors
found in desktop PC's so I've no clue about this...  :<

My assumption is that VRM's are just "very local" voltage
regulators designed to tweek the supply voltage to the
processor on a processor-specific (or even "on demand")
basis.  With core voltage approaching diode drops, the
losses in any *lengthy* signal distribution path would
be a challenge to overcome (one solution:  *local*
regulation).

But, how universal are the VRM's?  I assume *less* universal
than "PC power supplies" (which don't care if you're running
AMD, Intel or WhoopdeeDoDah).  I.e., are the signalling bits
from the processor to the VRM somewhat standardized?  Or,
does each manufacturer (or even processor model!) have a
different scheme?

Similarly, does the VRM connect to the host/motherboard by
some standardized interface?  Or, is the VRM seen as an extension
of the motherboard?

[To be more precise, is the VRM seen as part of the CPU or
as part of the motherboard, *conceptually*]

Bottom line:  can you swap VRMs between motherboard manufacturers?
CPU chip manufacturers?  Models of PC's?  etc.  I.e., if you
upgrade a processor in a brand X machine, do you bring a new
VRM to accompany the upgrade CPU?  And, must that VRM be supported
by manufacturer X?  Or, does the VRM in the brand X machine
handle all CPU upgrades supported by that machine?

Or, is it far less structured than all of this?

[Hmmm... I suspect I will need to cross post this elsewhere for
a detailed answer.  But, I'd be interested to hear the experiences
of anyone who has upgraded a CPU and the steps involved.  I'd like
to do this and/or add a second processor to some of the machines I
have here and would like to understand what I'm getting myself
into *before* tackling it!]

Thanks!
--don