Turbo boost working in Ubuntu but not in Windows

[Rikard]

Long time no see AnandTech...

On my i5-2500 Asus P8Z68-V/GEN3 rig I got this strange problem with turbo boost. I run a dual boot, and in Ubuntu I see the cores reaching 4.2 GHz (as they should with a multiplier of 41).

However, when I boot into Windows 7 64-bit the cores are stuck at x33. I checked with CPU-Z, AIDA64 and the Intel Turbo Boost Monitor, and they all agree that there is no turbo being enabled.

Since it is working in Ubuntu, it cannot be a bios problem, hence something in Windows is messing things up. I tried removing all ASUS and Intel tools, tried different chipsets, and I verified that the powerplan is set to High Performance. No effect.

I am out of ideas. Do you know why I am stuck with a multiplier of 33 in Windows but not in linux?

 

[ShintaiDK]

Tried changing the performance plan under power options?

 

[Rikard]

Tried changing the performance plan under power options?

Yes, it is in "High performance".

 

[LTC8K6]

I5-2500 is 33 to 37 multiplier.

With all 4 cores going, 33 is correct, yes?

 

[LTC8K6]

Try resetting the BIOS?

 

[ShintaiDK]

Yes, it is in "High performance".

You dont have any 3rd party tool/app that can change it? Where it may have been set as fixed to 33x.

 

[LTC8K6]

Found a thread that might help:

BCLK: 100.0
Turbo Ratio: by all cores
Multi: 45x
PLL Overvoltage: Auto
EPU Power Save: Disable
OC Tuner: Cancel/Off
CPU Ratio: Auto
Speedstep: Enabled
Turbo: Enabled
VRM: 350
Phase Control: Optimize
Duty Control: Extreme
CPU Current Capability: 110%
CPU Voltage: Offset Mode
Offset Mode Sign: +
Offset Voltage: Auto

Adaptive Thermal: Enabled
Active Cores: All
Limit Maximum: Disable
Virtualization: Disable
CPU C1E/C3/C6: Enabled

http://www.overclock.net/t/1173995/overclocking-i5-2500k-on-asus-p8z68-v-gen3/10

 

[Rikard]

Try resetting the BIOS?

I have reset it, no difference. Then OC again, no difference. I have not downgraded the BIOS yet, since that is quite complicated.

But like I said I am pretty sure the BIOS cannot be cause of the problem, since if I boot up in Ubuntu on the same machine I am getting the expected frequencies based on the OC multiplier. But not in Windows...

 

[ShintaiDK]

Well Windows can still control it via ACPI.

Perhaps you can find some hints in this guide to debug your issue:
http://www.overclock.net/t/1058894/intel-acpi-guide-c-g-s-p-states-and-ocs

 

[Rikard]

Well Windows can still control it via ACPI.

Perhaps you can find some hints in this guide to debug your issue:
http://www.overclock.net/t/1058894/intel-acpi-guide-c-g-s-p-states-and-ocs

Thanks I will look into it!

In the meantime these are the processes running, see anything suspicious that I missed?

 

[Denithor]

Stupid question, but I'll ask anyway: you have the machine under load when checking for boost clocks, right? Because it will down-clock the cores if not "needed" for power savings.

 

[coercitiv]

In the meantime these are the processes running, see anything suspicious that I missed?

Are you using the Intel Turbo Boost widget to monitor CPU speed?

On my Haswell system it fails to accurately report frequencies when CPU is idle. (shows base speed, not actual speed)

 

[Rikard]

Stupid question, but I'll ask anyway: you have the machine under load when checking for boost clocks, right? Because it will down-clock the cores if not "needed" for power savings.

Yes. It downclocks to a lower multiplier, but under load it stays at 33. Even when not OC-ed it turbo should take it to 37, and in my case to 41 with my settings.

Are you using the Intel Turbo Boost widget to monitor CPU speed?

On my Haswell system it fails to accurately report frequencies when CPU is idle. (shows base speed, not actual speed)

I am, but also CPU-Z, AIDA64 and now also Microsoft's pwrtest:


pwrtest.exe /ppm
Elapsed Idle C1 C2 C3 P- Freq Freq Perf/
Cpu [ms] [%] [%] [%] [%] State [%] [MHz] Throttle
--- ------- ---- --- --- --- ----- ---- ----- --------
0 4992 92 1 1 97 1 99 3300 P
1 4992 98 0 0 100 1 99 3300 P
2 4992 97 0 0 100 1 99 3300 P
3 4992 98 0 0 100 1 99 3300 P
0 9999 77 0 1 98 1 99 3300 P
1 9999 83 0 1 98 1 99 3300 P
2 9999 78 2 1 95 1 99 3300 P
3 9999 80 0 1 98 1 99 3300 P
0 45111 0 100 0 0 1 99 3300 P
2 45111 0 100 0 0 1 99 3300 P
3 45111 0 100 0 0 1 99 3300 P
0 50134 69 1 1 96 1 99 3300 P
1 50134 69 2 1 95 1 99 3300 P
2 50134 69 1 1 96 1 99 3300 P
3 50134 69 1 1 97 1 99 3300 P
This what I get when loading the cpu. It stays at P1, but it should go to P0 if I understand turbo boost correctly.

This is also strange; It looks like P0 is just 1 MHz higher than P1. It should be like 4100 MHz :'(

pwrtest.exe /infopm
InstanceName: ACPI\GenuineIntel_-_Intel64_Family_6_Model_42_-_________Intel(R)_C
ore(TM)_i5-2500_CPU_@_3.30GHz\_1_0

Processor Performance States
PerfStates:
Max Transition Latency: 10 us
Number of States: 16

State Speed (Mhz) Type
----- ------------ ----
0 3301 (100%) Performance
1 3300 ( 99%) Performance
2 3200 ( 96%) Performance
3 3100 ( 93%) Performance
4 2900 ( 87%) Performance
5 2800 ( 84%) Performance
6 2700 ( 81%) Performance
7 2600 ( 78%) Performance
8 2400 ( 72%) Performance
9 2300 ( 69%) Performance
10 2200 ( 66%) Performance
11 2100 ( 63%) Performance
12 2000 ( 60%) Performance
13 1800 ( 54%) Performance
14 1700 ( 51%) Performance
15 1600 ( 48%) Performance

 

[Bryf50]

Yes, it is in "High performance".

You want it in Balanced. I think High Performance defaults to 100% clocks minimum. Not sure why it's not turbo boosting. Check the minimum and maximum clocks in the power plan settings.