Can Optimus be turned off in BIOS in M6600, M4600, E6520, E6420?

That implies your E6420 has a mux and has patched through the NVS4200M to the LCD. Interesting. Very good news for Linux ppl. Muxless setups only allowing the Optimus functionality in Windows.

 

That's useful to know. I have been trying (in vain) to make an Intel graphics device appear to use Optimus (under Linux via Bumblebee) on my M4600 with an RGBLED screen. I can confirm there is no option in the RGBLED M4600 (A03) BIOS relating to Optimus.

If technically possible, I feel it would have been better to give users the choice of temporarily trading colour depth for battery life by enabling Optimus. Not every task requires amazing colour depth. The Quadro 2000M that is required for the RGBLED screen is rated at 55W. The X server settings dialog shows that when doing nothing (i.e. static desktop) its temperature oscillates between 52 and 59 celcius causing the fan to come on for about 10s every 90s. As you can imagine, that does wonders for battery life. (New 6 cell battery = approx 2 hours under light use.) I must add that my experiences are using the Linux NVIDIA driver 275.09.07 only.

Are other people finding similar behaviour on the M4600 or similar with Optimus turned off?

 

What Dell should have done with the IPS panel is allow Optimus to be enabled in the bios (or better yet, though a taskbar utility) that enables/disables Optimus. Enabling would use 8-bit color, disabling would use the dGPU all the time with 10-bit color.

 

For battery life, I really think you will want Optimus enabled - see my message above. I was in touch with another M4600 owner who got Bumblebee working though I don't know what distro he was using. Bumblebee is certainly getting less and less buggy.

 

Agree.

Dell don't give the slightest indication of this restriction for the IPS panel. When you look at the M4600 publicity material, Optimus support is stated and optional PremierColor technology a few lines below. No indication that these are incompatible. Can't say I'm happy about that.

 

Probably conflicting options that are probably only evident in the configurator, like how quad-core on the E6420 requires the nVidia graphics option (not that someone going through all that trouble to get a E6420 instead of a E5420 would be not getting the nVidia card).