Quote:
Originally Posted by NikosD
AVX2 had no such problems in the first implementation of Haswell.
The turbo modes of AVX2 were lower than any other mode, but this hasn't changed since then.
It's not that it was improved.
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Actually it was improved. In Haswell the entire CPU (ie. all cores) would clock down if any core used AVX2. Since Broadwell this is no longer the case, and only the core actually running AVX2 is clocking down if needed.
This resulted in a steep performance penality when using AVX2 in Haswell, which had people equally hesitant at first. But now AVX2 is quite useful in a multitude of applications, including Video.
Broadwell was also Intels first CPU to be made on Intels tri-gate transistor process, which helped efficiency and helped to reduce the power/heat requirements of the AVX2 units.
The really dense SIMD compute areas is where process improvements give the most benefit, since they produce the most heat on a small area.
I fully expect those clock offsets to improve with Ice Lake, whenever that comes out. Maybe by then developers have also figured out how to properly utilize it.