A merchant processor is a processor offered by a vendor
whose business model is selling processors to all takers
rather than bundled inside a system they sell. This is a
clear difference from house RISC model of the 1990s in
which Alphas, PA-RISCs, and POWER were generally not
sold on the open market and only available in systems
from the OEM that owned the architecture. Although some
RISCs like Alpha and SPARC were eventually offered to
other OEMs there were few takers because of competition
issues with the owner.

Why is IPF a merchant MPU?

1) Intel sells IPF processors to any interested party.
2) Intel does not sell IPF systems to end users.
3) IPF based systems are available from quite a few
different systems OEMs. With the recent move of the
HP MPU design team to Intel there is a level playing
field among all OEMs, both in perception and in reality.

None of the remaining high end RISCs are merchant chips.
Although IBM allows other OEMs to resell POWERx gear
it doesn't truly offer POWERx components to the open
market. And with POWERx primarily an IBM platform even
if IBM did offer devices on the open market the reality is
few OEMs would try to use POWERx components to
compete with IBM for system sales. Even if IBM initially
posed a level playing field history suggests the playing
field wouldn't stay level very long if competitors started
taking away IBM system sales using its own chips.

Why is IPF being a merchant so important? Easy, its a
more efficient business model and division of labour
than the house RISC business model. HW OEMs get
out of the increasingly costly processor development
business* and share the cost of IPF development with
many other OEMs in the price they pay Intel for the
processors. In return they get a high end MPU with at
least as much RAS, performance, and flexibility as
they likely could have afforded in their own design but
still retain the opportunity to differentiate and add value
to their own products with their unique system design
expertise. Their products also present one part of a
larger total market to ISVs than would a unqiue, vendor
specific ISA.

*Including programming tool chains and OS support.