W520 - Discrete graphic chip is enabled when external monitor is used

I just got my W520 and I am disappointed to find out my discrete graphic chip (i.e. Quadro 2000M) needed to be used when external monitor is being hooked up to my computer. That's will degrade my laptop battery life significantly. Also when I disconnect the external monitor, Optimus still can't switch the graphic back to Intel HD until I close apps such as Live messenger and Chrome.

Can I use Intel HD all the time? I only want to use 2000M when I am really using some 3D apps that requires discrete graphic chip's horsepower.

 

1) its a software/driver issue in which case this can be solved somehow

or

2) its a hardware design, that port is only routed from the nvidia GPU and the intel GPU can not talk to it directly


The programs keeping it on makes me think its #1

 

Seems like W520 can disable Optimus in BIOS. I believe the final display is sent through the IGP.

 

Disable Optimus in BIOS isn't an option because I do want to use the Quadra 2000M when needed. I just don't expect the chip need to be enable when external monitor, no matter whether display port or analog output is being used.

 

To my surprise, when I disable the Quadra 2000M from the BIOS and only use integrated graphic, none of the external monitors works anymore! I don't aware such a limitation on W520 being mentioned anywheree. The closest thing that I read is that W520 can't power 3 external monitors because of the optimus implementation is differently from T series. B

 

Well, I already started a thread about this.
You can't use the DisplayPort with integrated only. I know, it sucks, but Optimus does a very good job and I don't really miss the integrated only: the machine is quiet, and I can't see any reasons to care about the power consumption with it on AC (the power consumption difference between integrated only and Optimus is very low with my 1000).

 

Probably because nearly everyone (including me) are either running Optimus or full NVIDIA discrete.

 

What is the default configuration as we received the W520?

 

Pardon me, how do you check instantly whether discrete graphic card or INtel HD is running? I have Optimus turned on but not sure how to check which is activated at times

 

From NVidia Control Panel, select Desktop from the menu bar and select 'Display GPU activity Icon on Notification Area'. When you move the mouse over the icon, it will tell you how many programs are using Nvidia GPU. I have hook up the external monitor. Then launch several program and disconnect the monitor. I can see now there is 2 program running in Nvidia GPU - IE8 and Chrome. And in order for nVidia to switch off GPU, I have to explicitly kill those program.

 

I am using Optimus also. The problem is when nVidia GPU is triggered simply because of connect external monitor, and then I launch application that use GPU, no matter how I configure the nVidia Control center, those application will use nVidia GPU even after I disconnect the monitor.

Power usage wise, I can see with Quadra 2000M enabled, it use 18W - 21W power while I surfing the web vs 13-15W when I use Intel GPU. So 5W differences is significant. Yes, I can explicitly close those apps but that defeat the whole purpose of using Optimus - being seamlessly switch between 2 GPU.

 

Wait, let me get this straight... you're using an external monitor but complaining about battery life? I hate to be cheeky but does your external monitor also run off a battery? I ask because if you plug in your external monitor then I'd suspect you can plug in your laptop too.

 

I agree. Even if you need the huge power brick. There is nothing to complain about really.

FWIW, even the pre-optimus dedicated nvidia GPUs would change their power management behaviour when an external display is connected. You simply need to be able to drive much higher resolutions..

 

Its still wierd that he can not use external monitors without it changing to dedicated gpu

 

I agree with the other posters. Using an external monitor while using the laptop battery is a very unusual scenario. If you have power for the LCD panel you certainly have power for the laptop or dock, correct?

I would however like a technical explanation for the DisplayPort bug. Hopefully it will be resolved.

 

His problem is that his machine is using the discrete chip even after he disconnects the external display, and unless he restarts some apps, he's stuck with discrete.

Well that sucks, but at least you have a fix.

 

Is this issue just specifically related to when connected to an external monitor via the display port or is the issue also there when using a docking station?

 

Are you suggesting Optimus decides whether to use iGPU or dGPU based on the display devices in use? Now that would be cool. But I don't believe it's designed to do that.

Yea, apparently Optimus isn't magic.

 

Well, how can we check whether the integrated or the discrete chip is being used? I tell you how I do it, without any external tools: Nvidia Control Panel -> View system topology

So what do I see:
- restarted the machine, no external display connected: Quadro 1000M is adapter 2 of 2.
- plugged in an external display via DisplayPort, the internal display is not being used anymore: Quadro 1000M is adapter 1 of 2 (meaning the machine switched to discrete).
- unplugged the external display so that only the internal is being used: Quadro 1000M is adapter 2 of 2, meaning the machine uses the integrated now.

Well, Optimus ain't dumb either. I'm impressed.

Cheers

 

Just checked, one can also use CPU-Z to determine whether the discrete chip is used or not.
See under the Graphics tab, Display device selection, if that select/combo box is disabled, only the chip displayed with dark gray text is enabled (in my case Intel HD), if it is not disabled, both chips are active (remember, the discrete chip can't work alone without the integrated chip). You can also check the clocking of the discrete chip when it is activated by selecting it.

To enable your discrete chip in case it isn't, use some 3D app or go to "Adjust image settings with preview" in NVIDIA Control Panel. You must restart CPU-Z after the discrete chip is enabled.