> Meltdown/Spectre turned out not to be a reason big enough to upgrade from Sandy/Ivy Bridge, so they had to find another way to "discontinue" current users.
I sit beside the author of the Iris driver and work on the same team at Intel. The reasoning for only supporting BDW+ has absolutely nothing to do with spectre/meltdown or trying to force people to upgrade their hardware. Such a statement really indicates that you're not familiar with the people on Intel's Mesa team.
FYI the reasoning for only supporting BDW+ is that BDW+ supports 48-bit addressing which allows the CPU and GPU to share addresses trivially. This means no relocations are required and that's a great driver simplification and performance improvement.
BDW+ also supports executing all shader stages in the "scalar" (vs the vec4) mode, which allows much better opportunity for shader compiler optimization, which is the area I spend most of my time.
I sit beside the author of the Iris driver and work on the same team at Intel. The reasoning for only supporting BDW+ has absolutely nothing to do with spectre/meltdown or trying to force people to upgrade their hardware. Such a statement really indicates that you're not familiar with the people on Intel's Mesa team.
FYI the reasoning for only supporting BDW+ is that BDW+ supports 48-bit addressing which allows the CPU and GPU to share addresses trivially. This means no relocations are required and that's a great driver simplification and performance improvement.
BDW+ also supports executing all shader stages in the "scalar" (vs the vec4) mode, which allows much better opportunity for shader compiler optimization, which is the area I spend most of my time.