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Why have multicore chips if it saves no energy? In addition to TFA's reason, bluntly, because we have the transistors. Dennard scaling has ended which has mean
by CalChris 8y ago
Why have multicore chips if it saves no energy?
In addition to TFA's reason, bluntly, because we have the transistors. Dennard scaling has ended which has meant that we can't continue to increase clock frequencies. However, transistor counts have continued to increase. This has basically forced CPU manufacturers to focus on multicore because we have the transistors.
Also, big/little, gating off unused silicon and other approaches can save energy even as they use more transistors.
- jayd16 8y agoThere is also a heat aspect to this. You can run many cores at lower frequency to save on heat. This makes perf more consistent as you can avoid thermal throttle vs a single bursty core.
- vvanders 8y agoYeah, to do higher speeds(switching cost, F) you need higher voltages (V) so your power/heat goes up by non-linear variant of F*V. Depending on what your savings are for idle power it can either make sense to run long and slow or try and burst to a deep sleep state.