Just set the overall turbo multiplier instead of the by core multipliers. There may be an area where you can disable OS/core control of the multipliers or the turbo multis. And as long as c3/c6, etc aren't disabled, you should be ok.
I don't know if this applies to the M4E, but on the P8P boards, some (but apparently not all) people are having problems with the board downclocking and downvolting while idle, even with all power saving options disabled (all c states turned off) and windows set to high performance. Thread over on hardforum about that...
I think this is a BIOS bug, because it was proven that those boards KEEP the MSR for Speedstep ENABLED even if you disable it, and I guess they do some improper way of telling the OS it's disabled, which doesn't work right (and FAILS to work in Unix):
I did some testing, changing BIOS settings and reading out 0x1A0 (MISC_ENABLE).
1) EIST + Turbo enabled: 0x850089 + 0x00 (edx)
2) EIST disabled + Turbo enabled: 0x850089 + 0x00 (edx)
3) EIST enabled + Turbo disabled: 0x850089 + 0x40 (edx)
4) EIST + Turbo disabled: 0x850089 + 0x40 (edx)
1) is fine
2) is the case you mentioned, where EIST is in fact always turned on when Turbo is enabled. But I think the BIOS setting is misleading here. If the sole purpose of tying those two together is to enable users to set Turbo independently, then it makes no sense to even have the option when there is no difference in 1) and 2).
In fact, it would make sense to set a fixed multiplier of say 33x and only turn on Turbo Mode. That way, if thermal allows it, Turbo would kick in from 33 to the defined Turbo Ratio.
Intel specs do not suggest that EIST and Turbo must be tied together.
3) is fine, note that 0x40 in edx (high part of the 64bit register) is bit 38 for Turbo that disables it
4) is wrong. If both EIST and Turbo are disabled in BIOS, regardless of the design choice in 2), SpeedStep should be disabled completely. EAX should read 0x840089 (bit 16 for EIST).
This is also the case when setting the CPU Ratio manually to 33x. And if C1 is disabled as well.
In fact, if I disable EIST the "Ratio Range" (shown in the Information area above) should either be set to a fixed max_pstate or the custom entered "CPU Ratio". As of now, it shows 16-33 regardless.
Let me know if there are inconsistencies in my testing/reasoning, I'm happy to do another round of testing. I used CPU-Z and prime95 to confirm the MSR configurations.
Last edited by rdmsr64; Yesterday at 10:18 AM.
This doesn't happen on any other manufactuer's boards, including Asrock.....