xxcloud417xx said:
Does anyone here remember when Macs had the G series processors (last one was the G5)? What made them switch to Intel? and are Intel chips better or worse?
PowerPC.
PowerPC is a processor developed in the 90s by Apple, Motorola, and IBM.
Originally, PowerPC was notable as an example of a Reduced Instruction Set Computing (RISC) design. Intel's x86 chips at the time used a Complex Instruction Set Computing (CISC) architecture. RISC uses simpler and more limited machine code, meaning that certain operations that a CISC chip can do in one instruction have to be written out into several RISC instructions; the benefit is that it's easier to pipeline these instructions, meaning that execution of multiple instructions overlaps -- imagine the CPU as several different units arranged in an assembly line, with each unit doing its little part of an instruction and then passing it on to the next unit to finish.
Intel started designing CISC-on-RISC chips, which basically take in instructions in the old complicated x86 format but then transform them into RISC instructions for execution. Keeping the old machine code format allowed them to maintain backwards-compatibility with a lot of old code.
Over time, both the PowerPC and x86 architectures were improved and extended. For a while, PowerPC chips were notably for faster floating-point calculations while x86 chips did integer math faster. Both architectures added features like single-instruction/multiple-data processing. Motorola also came up with a few low-powered PPC designs for cell phones and other devices -- which IBM then used in their a massively parallel supercomputer designs. Overall, x86 chips changed a lot more than PPC chips -- partly due to a more dated original design, partly due to tight competition between Intel and AMD.
A few years back IBM ran into heat and wattage issues with their designs. This came at a time when Apple was getting more ambitious with its laptop roadmap. The company decided to switch to Intel processors because Intel chips were generally cheaper (mostly due to volume) and faster (due to a number of architectural and manufacturing factors). Intel had also stepped up development of cooler, lower-power chips for mobile devices, such as Atom and Celeron M.
Apple said that heat and performance problems were the main reason behind their move to Intel chips.
-- Alex
