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I have a Lenovo Thinkpad W520, with nVidia Optimus. What they didn't tell me was that the external VGA port is hard-wired to the nVidia GPU, so I can't use it

I have a Lenovo Thinkpad W520, with nVidia Optimus. What they didn't tell me was that the external VGA port is hard-wired to the nVidia GPU, so I can't use it at all when on the Intel GPU. Choice: battery life or external VGA? To make matters worse, it's a reboot to switch between them, and since I use Ubuntu which isn't supported (although props to the Bumblebee people for the progress they've made) it's hit-and-miss if even that will work. If the rest of the W520 wasn't such an awesome laptop, I'd be really quite upset. As it is, I just live with it and boot into Windows if I want to use a projector.

_delirium 13y ago
Any idea why it needs a reboot? Some MacBook Pro models have that kind of switching (integrated Intel + discrete nVidia) but don't need a reboot to switch between them. Is it some architectural thing, an issue with the nVidia drivers, an issue with Windows, ...?
- thristian 13y ago
  Modern Mac OS X is a bit smarter about things, but I believe the original versions of Mac OS X that supported Optimus required you to restart the windowing system when switching GPUs. That required quitting all your apps, logging out, and logging back in, which is effectively a reboot for people who stick to GUI interaction.
  - _delirium 13y ago
    Doing a little searching, it seems it might be tied to the hardware as well, not just the OSX version (not sure if that's a real hardware limitation or a driver issue though). The dual-GPU MacBook Pros from mid-2010 onwards have "automatic graphics switching" that does it on the fly: http://support.apple.com/kb/HT4110 http://support.apple.com/kb/HT4110 You're right that the 2008/09 models required logging out/in to switch manually; I hadn't realized that: http://support.apple.com/kb/HT3207 http://support.apple.com/kb/HT3207
    - fatrachet 13y ago
      There is a OSX tool called gfxCardStatus that can switch GPUs without logging out on the 08 and 09 models, works great on my 09 MBP, so it only seems to be a driver issue not a hardware limitation.
  - masklinn 13y ago
    > I believe the original versions of Mac OS X that supported Optimus OSX never supported Optimus, it's been a home-grown solution from the start.
seanalltogether 13y ago
I don't know about other PC laptops but I do know this is the case with macbooks, as soon as you plug in an external display you are kicked off the internal GPU and placed on the discrete one.
masklinn 13y ago
> I have a Lenovo Thinkpad W520, with nVidia Optimus. What they didn't tell me was that the external VGA port is hard-wired to the nVidia GPU FWIW, mixed-GPU Apple laptops have the exact same issue (although there's no reboot necessary), external displays can only be driven from the discrete GPU not the integrated one.
nly 13y ago
> Choice: battery life or external VGA? If you're using external VGA, aren't you by definition tethered? When are you likely to use external VGA and yet don't have access to power?
- kevinbowman 13y ago
  Meetings, presentations etc - I may not have my power brick with me.

_delirium 13y ago

Any idea why it needs a reboot? Some MacBook Pro models have that kind of switching (integrated Intel + discrete nVidia) but don't need a reboot to switch between them. Is it some architectural thing, an issue with the nVidia drivers, an issue with Windows, ...?

thristian 13y ago
Modern Mac OS X is a bit smarter about things, but I believe the original versions of Mac OS X that supported Optimus required you to restart the windowing system when switching GPUs. That required quitting all your apps, logging out, and logging back in, which is effectively a reboot for people who stick to GUI interaction.
- _delirium 13y ago
  Doing a little searching, it seems it might be tied to the hardware as well, not just the OSX version (not sure if that's a real hardware limitation or a driver issue though). The dual-GPU MacBook Pros from mid-2010 onwards have "automatic graphics switching" that does it on the fly: http://support.apple.com/kb/HT4110 http://support.apple.com/kb/HT4110 You're right that the 2008/09 models required logging out/in to switch manually; I hadn't realized that: http://support.apple.com/kb/HT3207 http://support.apple.com/kb/HT3207
  - fatrachet 13y ago
    There is a OSX tool called gfxCardStatus that can switch GPUs without logging out on the 08 and 09 models, works great on my 09 MBP, so it only seems to be a driver issue not a hardware limitation.
- masklinn 13y ago
  > I believe the original versions of Mac OS X that supported Optimus OSX never supported Optimus, it's been a home-grown solution from the start.

seanalltogether 13y ago

I don't know about other PC laptops but I do know this is the case with macbooks, as soon as you plug in an external display you are kicked off the internal GPU and placed on the discrete one.

masklinn 13y ago

> I have a Lenovo Thinkpad W520, with nVidia Optimus. What they didn't tell me was that the external VGA port is hard-wired to the nVidia GPU FWIW, mixed-GPU Apple laptops have the exact same issue (although there's no reboot necessary), external displays can only be driven from the discrete GPU not the integrated one.

nly 13y ago

> Choice: battery life or external VGA? If you're using external VGA, aren't you by definition tethered? When are you likely to use external VGA and yet don't have access to power?

kevinbowman 13y ago
Meetings, presentations etc - I may not have my power brick with me.