Watts the Matter with Desktop Processors?
This approaching bifurcation in x86 processor design between the desktop and mobile markets has two main causes. The first is the fact that the power consumption of x86 desktop processors has grown well beyond the point at which simple requalification of screened parts with lower supply voltages and slap-on power management logic can bring down their power levels enough to be compatible with the battery and thermal dissipation capacity of most portable computers. This problem is even more pronounced for hand-held computing applications where x86 compatibility is not usually required. A multitude of inexpensive, low power RISC processors are obvious and credible alternatives to x86 MPUs.
The second reason why mobile processor design is emerging as a separate discipline is the growing economic importance of the mobile processor market, as well as the competitiveness of the players. While the desktop processor market is currently experiencing painfully slow growth and intense price competition, the perennially robust mobile market (which is currently dominated by Intel) has much higher prices and margins. It is no surprise that AMD will target the mobile market first when it rolls out its new ‘Palomino’ design later this year . There is also a potentially large market for low power x86 processors in high density rack mounted servers that pack many more CPUs in a given amount of floor space than is currently practical with desktop devices.
The degree to which contemporary desktop processors must be frequency and voltage derated to bring down power consumption to workable levels for mobile applications is akin to pounding the proverbial square peg into a round hole. It is not only inefficient, but advances in process technology will make it even more so in the future. That mismatch, combined with the growing economic importance of the mobile market to x86 vendors, provides strong incentive to design a new processor core from the ground up to carefully balance power efficiency with performance. The rest of this article is dedicated to technical speculation about what approaches Intel and others might take in making a ‘cool’, yet reasonably high performance x86 processor design.
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