Originally Posted by CSMR
But they are not measurements. They are chosen from a set of numbers - 25W, 45W, 65W, 95W etc. that are clearly not measurements, and I'm sure this set of possibilities not chosen by engineers. Presumably this set is chosen by marketing, so people don't get confused by more exact numbers, and so they don't understand the tradeoffs involved in picking a higher processor speed. This is not a criticism.
To guage power consumption you need measurements; TDP only gives you a very vague bracket for load power consumption.
I understand your point, but I can tell you that that is not how we determine TDP for our processors. These are not randomly chosen numbers pulled out of the air by marketing.
I think you may be confusing an MRD (Market Requirements Doc) that specify major feature sets for a given market, but marketing does not determine what TDP is set for a given processor. TDP is determined by numerous factors, including process technology, processor layout, functions/features enabled on a processor, etc. Our TDP is in fact determined by extensive testing by our validation engineers.
Keep in mind, our definition of TDP is different that what Intel defines as TDP. We define TDP as more of a max power, i.e. if we state a 25W TDP for that processor, then we are saying that the power will not exceed 25W. Intel's definition of TDP is typical power and therefore process could exceed stated TDP.
AMD Definition (see page 29)http://support.amd.com/us/Processor_TechDocs/30430.pdf
Intel Definition (see page 10 and page 35)http://download.intel.com/design/pro...nex/322912.pdf