Can't get below 40W idle on Haswell CPU.
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Can't get below 40W idle on Haswell CPU.
Hello,
I have a new computer with an i7-4790, 3 SSD disks and 32GiB of memory.
For some days since I started using it I was measuring ~20W at idle load with it, since I touched something on BIOS I can not get it to go below ~40W.
I have tried to reset the BIOS and load default values but doesn't help. I don't get what can be the cause, I don't find anything obvious on BIOS settings, everything seems correct.
Any hint about this?
I have a new computer with an i7-4790, 3 SSD disks and 32GiB of memory.
For some days since I started using it I was measuring ~20W at idle load with it, since I touched something on BIOS I can not get it to go below ~40W.
I have tried to reset the BIOS and load default values but doesn't help. I don't get what can be the cause, I don't find anything obvious on BIOS settings, everything seems correct.
Any hint about this?
Re: Can't get below 40W idle on Haswell CPU.
Tracked down your build thread so we have an idea of what's in it.
Run CPU-Z and the task mgr (cntl-alt-del) to see if the cpu is idling and what tasks are running. Maybe something is loading at start up that shouldn't be or isn't idling out.
Run CPU-Z and the task mgr (cntl-alt-del) to see if the cpu is idling and what tasks are running. Maybe something is loading at start up that shouldn't be or isn't idling out.
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Re: Can't get below 40W idle on Haswell CPU.
Make sure the settings mentioned in the link below are explicitly set as On or Enabled instead of Auto
http://www.xbitlabs.com/articles/cpu/di ... ing_2.html
http://www.xbitlabs.com/articles/cpu/di ... ing_2.html
Re: Can't get below 40W idle on Haswell CPU.
Use balanced as your power settings under windows, if you dont allow it down clock to 800mhz it will never go down to 20W idle.
Re: Can't get below 40W idle on Haswell CPU.
Hi guys,
thank you for your answers!
I've checked all settings on BIOS. As I use Linux I've not been able to use Windows tools, but anyway I managed to stop any program so I got the cpu at 800Mhz almost 100% of the time, and it went down to 34W.
I start to think that my wattage measure gadget is not working correctly, it did some strange thing before, so I realize that my real power consumption is on 40W on idle desktop usage.
thank you for your answers!
I've checked all settings on BIOS. As I use Linux I've not been able to use Windows tools, but anyway I managed to stop any program so I got the cpu at 800Mhz almost 100% of the time, and it went down to 34W.
I start to think that my wattage measure gadget is not working correctly, it did some strange thing before, so I realize that my real power consumption is on 40W on idle desktop usage.
Re: Can't get below 40W idle on Haswell CPU.
Either the gadget is broken or something is wrong with the mobo or pico. That build, even with a few 12CM low rpm fans and an efficient psu, should not pull more than 25W at idle.
Re: Can't get below 40W idle on Haswell CPU.
Thank you very much for the suggestion, didn't think about that. But I changed the power supply and the consumption was the same.Tzeb wrote:Either the gadget is broken or something is wrong with the mobo or pico. That build, even with a few 12CM low rpm fans and an efficient psu, should not pull more than 25W at idle.
I think I got confused by this kill-a-wat like which is broken.
Re: Can't get below 40W idle on Haswell CPU.
Get another kill-a-wat, or an ups with usb and let us know the real idle pull.
Re: Can't get below 40W idle on Haswell CPU.
Hi guys,
got another measure gadget, same results.
I guess 37W is my absolute minium (with 3 ssd), not that bad compared to my old Q6600.
Thank you again!
got another measure gadget, same results.
I guess 37W is my absolute minium (with 3 ssd), not that bad compared to my old Q6600.
Thank you again!
Re: Can't get below 40W idle on Haswell CPU.
Something is wrong on your part.
I've tested another build yesterday.
g3258
GA-H81M-DS2
4GB DDR3 @1.5V
1 ssd
2 12 CM fans@~550 RPM
Some crappy FSP ATX-400PNF (don't think efficiency is strong in this one )
Idle is at ~21W, sometimes ever under 19.
37W idle is bad. You should see half that with a good psu.
I've tested another build yesterday.
g3258
GA-H81M-DS2
4GB DDR3 @1.5V
1 ssd
2 12 CM fans@~550 RPM
Some crappy FSP ATX-400PNF (don't think efficiency is strong in this one )
Idle is at ~21W, sometimes ever under 19.
37W idle is bad. You should see half that with a good psu.
Re: Can't get below 40W idle on Haswell CPU.
The motherboard is usually what makes up at least some of the difference. I would guess that the GA-H81M-DS2 is more efficient at idle compared to the GA-Q87M-D2H.
Re: Can't get below 40W idle on Haswell CPU.
That q87m can't make THAT much of a W difference if all is working as it should. At first he was reading ~20W.
Here is what i would do...
Leave just one stick of ram, just the boot ssd drive, disconnect any fans or whatever could pe removed. Boot, wait for idle, measure.
If you don't read under 25W, something is broken for sure.
Here is what i would do...
Leave just one stick of ram, just the boot ssd drive, disconnect any fans or whatever could pe removed. Boot, wait for idle, measure.
If you don't read under 25W, something is broken for sure.
Re: Can't get below 40W idle on Haswell CPU.
There is not much I can remove. Only the front 18cm fan and three of the four memory sticks.
Based on what you say something must be wrong. I suspect it is related to the motherboard, but resetting BIOS didn't make any difference neither, I have to recheck that and the hardware.
Based on what you say something must be wrong. I suspect it is related to the motherboard, but resetting BIOS didn't make any difference neither, I have to recheck that and the hardware.
Re: Can't get below 40W idle on Haswell CPU.
From my linux days I remember having a bit similar trouble. CPU in idle would drop clocks but not volts. Wrong kernel or wrong speedstep module, I dont remember.jormartr wrote:Based on what you say something must be wrong. I suspect it is related to the motherboard, but resetting BIOS didn't make any difference neither, I have to recheck that and the hardware.
It could explain 15-20W difference on a normal CPU, but a low power T version? Not sure.