I've not been using a seperate graphics card for a while now, my computers beeing only used for surfing. Now I've gotten my hands on a nice i5, but it's in a half-height case. I know there are half height cards out there, but my case is whisperquiet, and the half height craphics cards…..aren't. I seem to remember here was a trick to using the on-board graphics, and the graphics card at the same time. Connecting only the on-board DP or HDMI, but using the Graphics Card for specific programs (games), while the rest of the (dull) time, the on-board graphics are running for desktop and surfing and the like. Do I remember this correctly? This would allow me to "hide" a full height Graphicscard in my case without plugging it in from the outside.
The first effort was the buggy Lucid Virtu system - Z68 era (I think)? Which was supposed to use the iGPU to supplement the GPU. From Haswell onwards, I believe there was a multi-monitor option in the BIOS where the igpu would drive a second screen from the onboard ports, but I don't think it aided the GPU performance.
Alienware used a tech like this for the M11x and other laptops. The main GPU only did anything when you put a gaming load on it.. However it was flawed deeply as Alienware couldn't keep up with Nvidia and thus you had to wait months for a driver update not the few weeks for the OEM ones. I know you can use pass through, but IIRC the last time I studied it you needed to hack the driver.
I remember it was a big discussion when iGPU's first became common, (around Sandy Bridge time?) but can't find anything about it. Getting Old