Hi,
I was doing some experimenting to determine how low I can get my computer power consumption without putting it to sleep. I prefer to leave it on so it can keep working on light background tasks (none running during testing of course).
With all the display cables disconnected, I can get down to about 75 W. I'm measuring the AC power between the computer PSU and mains. I'm not measuring the power from the displays themselves.
I noticed that connecting my primary display with the DisplayPort cable adds about 32 W to total power (+43%!). My secondary display over VGA seems to have no significant effect on power consumption.
So I configured Windows to turn off my displays after 1 minute, expecting to save 32 W when it goes. I was surprised to find out that power consumption stayed the same. D: I also tried pulling the power cord from the display, but still no change. Finally I pulled the DisplayPort cable and the power dropped 32 W.
I don't know how DisplayPort is designed to work, but it seems kind of stupid to me that I need to physically pull the display cord to save power.
Not sure who/what to blame. Microsoft? AMD? VESA? ASUS? myself? (surely not myself!) Anyone else noticed this?? I would test with integrated Intel GPU, but I only have a mini-DisplayPort cable. I'll try to get my hands on a regular DisplayPort cable.
My setup:
ASUS Z97-Pro
Intel 4790K
8 GB RAM
AMD Radeon HD 7950
PSU... can't remember... something way too big to be efficient at low power...
primary display: ASUS VG248 1920x1080@144 over DisplayPort
secondary display: HP w2408h 1200x1920@60 over VGA (HDMI broken)
Windows 7 64 bit, balanced power profile, similar results with power save profile
I was doing some experimenting to determine how low I can get my computer power consumption without putting it to sleep. I prefer to leave it on so it can keep working on light background tasks (none running during testing of course).
With all the display cables disconnected, I can get down to about 75 W. I'm measuring the AC power between the computer PSU and mains. I'm not measuring the power from the displays themselves.
I noticed that connecting my primary display with the DisplayPort cable adds about 32 W to total power (+43%!). My secondary display over VGA seems to have no significant effect on power consumption.
So I configured Windows to turn off my displays after 1 minute, expecting to save 32 W when it goes. I was surprised to find out that power consumption stayed the same. D: I also tried pulling the power cord from the display, but still no change. Finally I pulled the DisplayPort cable and the power dropped 32 W.
I don't know how DisplayPort is designed to work, but it seems kind of stupid to me that I need to physically pull the display cord to save power.
Not sure who/what to blame. Microsoft? AMD? VESA? ASUS? myself? (surely not myself!) Anyone else noticed this?? I would test with integrated Intel GPU, but I only have a mini-DisplayPort cable. I'll try to get my hands on a regular DisplayPort cable.
My setup:
ASUS Z97-Pro
Intel 4790K
8 GB RAM
AMD Radeon HD 7950
PSU... can't remember... something way too big to be efficient at low power...
primary display: ASUS VG248 1920x1080@144 over DisplayPort
secondary display: HP w2408h 1200x1920@60 over VGA (HDMI broken)
Windows 7 64 bit, balanced power profile, similar results with power save profile
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