This has been an issue with every BIOS I've had---even the latest (2101?).
Basically, I have been trying to get this 9590 stable with a very, very mild overclock to 5ghz constant since the day I got it.
It seems pretty stable now (~5.0), but here's the odd thing:
When I MANUALLY set the vcore to the ~1.53-~1.57 range (tried all three) I can never, ever get the system to be stable.
When I set it to auto, the system is stable, but when I look in CPU-Z in windows, the Vcore under load is in that range (1.53-1.57).
Also, further confounding me---if I put the cpu at its stock setting (4.7) the system *should* be stable with a fixed vcore of 1.475 or so (turbo off in any of these cases, BTW), right? And yet, if I dont leave the vcore at "Auto" the system just wont be stable.
Of note: To get this cpu stable at the stock factory settings (either 4.7/5.0 turbo or 4.7 constant, no turbo) I had to manually go into the DIGI+ power control menu and change settings there. It just seems to me that for a board that seems MADE for the special 9590 cpu, and one of the most recommended, that ASUS would have a BIOS capable of running the cpu stable at stock speeds without having to fine-tune enthusiast overclocking settings.
BTW, the settings I changed in the DIGI+ menu, for those who are having trouble stabilizing 9590 at stock speeds are as follows:
CPU Current Capability = 130%
CPU Power Phase Control = Extreme (disables phase shedding)
CPU Power Switching Frequency = Manual
VRM Fixed Frequency Mode = 300kHz
CPU Power Duty Control = Extreme
CPU Power Response Control = Medium
CPU Power Thermal Control = 130
VRM Over Temperature Protection = Enabled
Edit: Forgot to add-- Load Line is set to Regular (0%)--this one seems to be very important.
Used these as recommended in this thread, and it works.
http://www.overclock.net/t/1496284/huge-issues-with-9590-and-stability/10