3 ms·
The reference provided by nkurz measured clearly that it is a net win in most cases. However, that fact isn't inherantly obvious. CPU's aggressively use clock
by brandmeyer 11y ago
The reference provided by nkurz measured clearly that it is a net win in most cases. However, that fact isn't inherantly obvious. CPU's aggressively use clock gating to shut down idle parts of the processor at a fine-grained level. So avoiding the use of several entire compute units does have some savings as well. The difference is that I was assuming something more like 2x power usage, where the actual difference is in the small single digits.
- Sanddancer 11y agoAlso, keep in mind how little of the modern CPU's die space is actually dedicated to the traditional cores. A quad-core skylake processor dedicates over half its space to things other than CPU cores [1], and that each core itself has a lot of space needed for paths that are always going to be used, like instruction decoding and storing the registers. So gating in a situation like this is only ever going to turn off a very small bit of the processor. [1] http://www.techpowerup.com/img/15-08-18/77a.jpg http://www.techpowerup.com/img/15-08-18/77a.jpg