XLR8, a manufacturer of Mac multiprocessor upgrades and expansion products,
has posted a white paper
that releases into the public domain information allowing a manufacturer to enhance current Power PC 7400 ZIF processor card designs.
This specification optimizes cache coherency and enables the processor for use in multiprocessing architectures such as the XLR8 MACh Velocity MPe and the MACh Carrier G4 MPe.
“With the tremendous performance benefits that come from using dual processors in Mac OS X and 9.1 today, multiprocessing will become the way to give current machines much greater performance,” Jack Kolk, vice president and general manager of XLR8, said in a statement. “With the SMP [symmetrical multiprocessing] architecture of OS X and a second MPe enabled ZIF processor, the result is up to twice the performance.”
XLR8 designed the MPe ZIF to overcome the limitation created by the lack of multiprocessing support the current ZIF processor design used in many of the more popular recent Mac systems, he said. The specification allows for Power PC G4 processors to communicate in a much more efficient manner in order to optimize multiprocessing support, Kolk added. The communication methodology is the standard supported by the 7400 Power PC or G4 processor family but it requires circuitry support that, up until XLR8’s MPe design, had not been implemented.