Why is there no AMD Hybrid on Desktops and what are the limitations?

[Lorez27]

Hi, working out a PC compatibility department and after troubling shooting an issue concerning Intel CPU + AMD GPU (AKA: AMD Hybrid), this raised a question.
I know that this only applies to Laptops, and not even all of them at that (checking on a Alienware M18x which does not support this)

Is there any work around to enable this, for example ANY Intel Onboard + AMD GPU?
What are the Limitations to explain for the Laptop Specifics?
If there is a work around to install what may this be?

I suppose the same question also applies to Nvidia Optimus, but I'm only interested in the AMD side of it in this specific scenario

Thank you for your time!

 

[inerax]

I guess i do not understand. I run an i7 and dual AMD 6950's. What do you need to workaround?

 

[Lorez27]

On many Laptops, that have Intel Onboard and a discrete AMD or Nvidia graphics. You can right click an application and select which Graphic output you want to send it to.
Or when booting a game, it will automatically send it to the Video card. While opening Firefox will most likely send it to the Intel HD Onboard and put your GPU to sleep for power efficiency.

 

[getochkn]

On a lpatop though, the output for the video is direct to the screen. On a PC, if you have an intel CPU or AMD APU, that outputs video from the CPU direct to the HDMI/VGA/DVI port on the motherboard. If you have a GPU, it will output the video to the HDMI/VGA/DVI on the video card. There in lies the problem. How do you output the video from the Intel CPU to the GPU outputs or vice versa.

 

[Eximo]

I believe AMD does support this capability on desktops with AMD APUs and a discrete GPU, you can get the 'Dual Graphics' output through the motherboard or the GPU on some motherboards.

But that is basically crossfire, not hybrid graphics.

 

[Lorez27]

Hmm good point about the output, I suppose that throws a massive wrench into the equation.
Although that would not apply to the M18X I just tried out, The Funct+F7 command would reboot the Laptop and switch GPU while still using the same output. Yet the option to switch between GPU's could not be done on the fly like Optimus or Hybrid and needed a full reboot.
As I only have a handful of Laptops at my disposition here I am unable to confirm if it is just an issue with Alienware laptops or other high end ones aswell.

 

[Martell1977]

The only reason for the "Switchable" graphics is to save power. The discreet GPU uses more power and with a laptop running on battery it would greatly reduce usage time. On a desktop, there is no need for this as it is always connected to a power source.

As mentioned before, laptops are a single connection to the screen that is shared between the 2 GPU's, while desktops have several separate connections. Plus, the switchable graphics are enabled using specific drivers for that compatibility.

The closest thing on a desktop is Hybrid Crossfire for AMD, which is running an APU's IGP in crossfire with a lower end AMD discreet GPU to increase performance.

 

[getochkn]

http://lucidlogix.com/products/virtu-mvp-2-0-for-windows/

This software allows you to use the intel gpu in conjuction with a gpu for a boost in power, so they say, but not one or the other without switching cables or at least monitor/tv inputs and possibly a reboot.

 

[k1114]

This is not amd hybrid, which refers to nothing. Hybrid cf is the closest thing as far as the name goes. I believe what you are referring to is amd switchable graphics. The reason this does not exist on desktops because power is not a concern and has such a little effect that it's only useful for battery life. This does work on any intel igpu and amd mobile dgpu but some laptops don't have it. As I understand, there is extra circuitry to allow them to switch seamlessly. My y500 doesn't have optimus even though subsequent models do and there is no way I can have it even though they use the same cpu and gpu.

Getting a bit off topic but you can output dgpu through igpu or vice versa on a desktop with virtu. I had to do it because when I moved I forgot my mini hdmi adapter and wasn't going to settle with using my igpu. It worked mostly fine but I still think virtu is mostly trash. It does not really use the igpu in tandem with the dgpu in the sense you think. There is an in depth explanation on it and shows the igpu does no actual graphic work, it sorts through what the dgpu should render.