reasons for not having optimus in M4800 http://www.dell.com/support/troubleshooting/us/en/04/KCS/KcsArticles/ArticleView?docid=627037
good machine but now I have it and think its not as good as adverts say (good built otherwise sharp corners but if it worked id be happy)
Hers another problem with QHD 3200x1800 screen on Dell M4800 http://forum.notebookreview.com/dell-latitude-vostro-precision/742205-dell-precision-m4800-screen-st...
It was a conscious design decision. The M4x00 line is Enterprise oriented. They come with BIOS firmware options to direct all graphics output through the NVIDIA card -> effectively bypassing the discreee graphics processor and Optimus option behavior altogether. Enterprises with sizable engineering departments require this because many of them run several pieces of rendering software that don't react well to graphics switching behavior and need all output to go through the advanced graphics card at all times in order for them to behave robustly.
These key clients don't give a fig about the battery life benefits of Optimus and Haswell, they want their 3D apps to perform .. robustly. They'll take the weight drop Haswell provides, and accept any battery life savings it delivers too ... but only as long as their apps continue to work well.
I call . This is the weakest argument I've ever heard.
If that were the case, why enable it on the 1920x1080 screen? I appreciate the desire for an option to disable it, but that's not universally available. More of a case of I can't be bothered to properly redesign the motherboard to accommodate this high-resolution screen.
Engineers value battery life as much as the next person - why not get a Precision desktop otherwise?
I agree with you because the whole notion that applications do not like graphics switching is bogus because it is not switching. All graphics data from nvidia's frame buffer is DMA'ed through PCIe to the intel GPU frame buffer while using optimus. So there is not real switching.
I am R&D engineer and do a lot of simulation, FPGA PAR... etc and I can tell you that the main reason for not picking the 4800 is indeed that the High DPI version does not support optimus.
It is quite simple Dell dropped the ball because they used the eDP channel to translate to lvds to drive the 1080p panel and as such cannot drive a dp panel like the high dpi panel through the same interface (intel GPU). It has NOTHING to do with BIOS what so ever. It is a hardware issue we use the same approach in our products => use eDP to lvds convertor (NPX device) to convert to lvds to drive most of the existing lcd panels.
Hence I decided to wait and I ordered the HP Zbook15 G2 with high res screen. Apparently HP did not make the same design mistake as Dell.