Confusion in AMD’s Whitepaper on Phenom’s ACP and TDP value

Two recent whitepapers published by AMD created hot rebate concerning the ACP (Average CPU Power) on its K10 Phenom processor. Besides creating the question on how the ACP delta between these two whitepapers, some readers also raised concern on how the ACP indicates when comparing to TDP (Thermal Dissipation Power), which is used to be the standard benchmarking used by both Intel and AMD. ACP is a new standard being deployed by AMD that supposed to indicate the power consumption based on typical application scenario. According to AMD, ACP is comparable to TDP measurement that is published by its competitors, Intel.

Whereas for TDP, it represents the maximum specification of the cooling system in a computer that is required to dissipate in order for the system to work well. As listed in below table, it is clearly stated that the TDP published for whitepaper 1 and 2 are about 20W increase. However, there is no increase in corresponding ACP figures. The author of whitepapers did clarify that this is the margin in calculation. However, it is not convincing by looking at how the margin doesn’t apply to TDP.

Whitepaper is significant important tool for the manufacturer to publish solid performance data for external customers. This serves as one of the major reference especially for those OEMs that would like to benchmark and choose among all the competitor’s products. In this scenario, it creates a misunderstanding and confusion especially followed all the rumors when AMD struggled to raise the processor clock on its Phenom family. Suspiciously, there could be thermal constraint in AMD processor that severely limits the increase in processor clock frequency.