Does anyone know the numbers of build servers and the specs?
There are 8,760 hours in a non-leap year. Electricity in the U.S. averages 12.53 cents per kilowatt hour[1]. A really power-hungry CPU running full-bore at 500 W for a year would thus use about $550 of electricity. Even if power consumption dropped by half, that’s only about 10% of the cost of a new computer, so the payoff date of an upgrade is ten years in the future (ignoring the cost of performing the upgrade, which is non-negligible — as is the risk).
And of course buying a new computer is a capital expense, while paying for electricity is an operating expense.
1: https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...
However the AMD CPUs did not implement it until Bulldozer, in mid 2011.
While they lacked the many additional instructions provided by Bulldozer, also including AVX and FMA, for many applications the older Opteron CPUs were significantly faster than the Bulldozer-based CPUs, so there were few incentives for upgrading them, before the launch of AMD Epyc in mid 2017.
SSE 4.1 is a cut point in supporting old CPUs for many software packages, because older CPUs have a very high overhead for divergent computations (e.g. with if ... else ...) inside loops that are parallelized with SIMD instructions.
I was hit by this scenario in the 2000s with an old desktop pc I had, also in the 10ys range, I was using just for boring stuff and random browsing, which was old, but perfectly adequate for the purpose. With time programs got rebuilt with some version of SSE it didn't support. When even firefox switched to the new instruction set, I had to essentially trash a perfectly working desktop pc as it became useless for the purpose.
It's amazing how long of a run top end hardware from ~2011 has had (just missed the cutoff by a few months). It's taken this long for stuff to really require these features.