Sequential reads and low queue tests don't appear to be affected much for home users by the 80 series microcode update. Random 4K high queue is most impacted under CDM benchmarks for me:
i7-8700K on Z370 Taichi + 960 EVO 250GB, Windows patch installed, no UEFI/microcode update (UEFI 1.30):
Random Read 4KiB (Q= 32,T= 1) : 514.705 MB/s [ 125660.4 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 687.330 MB/s [ 167805.2 IOPS]
Random Read 4KiB (Q= 1,T= 1) : 43.424 MB/s [ 10601.6 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 156.527 MB/s [ 38214.6 IOPS]
i7-8700K on Z370 Taichi + 960 EVO 250GB, Windows patch installed, UEFI/microcode update installed (UEFI 1.40):
Random Read 4KiB (Q= 32,T= 1) : 305.985 MB/s [ 74703.4 IOPS] -40.6% IOPS
Random Write 4KiB (Q= 32,T= 1) : 413.083 MB/s [ 100850.3 IOPS] -39.9% IOPS
Random Read 4KiB (Q= 1,T= 1) : 43.245 MB/s [ 10557.9 IOPS] within MOE
Random Write 4KiB (Q= 1,T= 1) : 121.128 MB/s [ 29572.3 IOPS] -22.6% IOPS