My Lenovo W520 is the best laptop I have owned, but I have had one major issue with it, external projectors. The problem is it does not like to duplicate the laptop screen output to a projector, it works fine if extending the desktop, not duplicating.
Every time I have tried to use it with a projector I either end up only showing on the projector and looking over my shoulder, or fiddling for ages until it suddenly works, usually at a low resolution, I don’t know what I did to get to this point so I don’t dare fiddle any more so use it anyway. A bit of a problem given the number of presentations I do. A quick search shows I am not alone in this problem.
The issue it seems is down to the fact the Lenovo has two graphics systems, an integrated (Intel) one and a discrete (Nvidia) one. The drivers in Windows 7 allow it to switch dynamically between the two to save power. This is called Nvidia Optimus Switching.
The answer to the problem is to disable this Optimus feature in the BIOS, this is at the cost of some battery life, but better to have a system that works as I need and have to plug it in, than does not work at most client sites.
So to make the change
- Reboot into BIOS (press the ThinkVantage button)
- Select the Discrete graphics option (the Nvidia 1000M)
- Disable the Opitmus features
- Save and Reboot
- Windows 7 re-detects all the graphics drivers and then all seems OK (so far…)
On more point it is worth noting I again fell for the problem that as my WIndows 7 partition is BitLockered you have to enter your recovery key if you change anything in the BIOS, see my past post for details of how to fix this issue. Was a bit surprised by this as I thought BitLocker would only care about changes to the master boot record, but you live and learn.