APU + Dedicated graphic card

[ggelli2014]

I noticed that many recent notebooks have an apu and also a dedicated graphic card.

My understanding is that an APU has an integrated GPU.

For instance the LENOVO Ideapad 320-15ABR/80XS00CKIX has an AMD A12-9720P APU (with AMD Radeon R7 integrated GPU)
plus an AMD Radeon 530 dedicated GPU with 2 GB dedicated video memory.

I wanted to ask if in this case the integrated and the dedicated GPU work together, and if not what is the use
of having a system with both an APU and a dedicated GPU.

Thank you very much in advance!

 

[shmoochie]

My guess is that the manufacturer gets a bulk deal on processors, and the cpu with the apu is the only option that works with low and high end laptops. Cheap laptops get just the apu, and the expensive versions gets a discrete gpu added in. If they bought another type of cpu for the laptops with discrete gpus, then they would lose money due to losing the bulk deal and also due to the added organization and manufacturing costs.

edit: I forgot to say that they also have them set up to use the apu for less intensive tasks because it is cooler and uses less power.

 

[drawingpin]

They more than likely disable the APU graphics in the BIOS.

 

[k1114]

It's not a recent development. Igpus being on nearly every cpu has been around for almost a decade. Economy of scale. But to get on topic. Apus have some setups that use both together but as with any multi gpu setup, many games don't take advantage and some see a decrease in performance. For this reason amd has stopped supporting dual graphics, which is what amd calls apu igpu+dgpu, for a couple generations now. So for that laptop and any recent laptop (or with intel and older), they switch between gpus depending on use for power saving.

 

[dontlistentome]

I think sometimes it's just marketing.

Let's say you sell a laptop with an APU. Your competitor sells a similar laptop and sticks a low end dedicated GPU in there. Now that laptop sounds like a better deal to the average consumer.

The proof one way or another can be found in analyzing which dedicated GPU they included. APUs have integrated graphics that are suitable for general, non gaming use. If the manufacturer includes a low end GPU which is also only suitable for general, non gaming use, they're just using it for marketing purposes.

In the case of that Radeon 530, if the 2gb vram it includes is DDR5 then you could justify it as a legitimate improvement over the APU graphics. If it's DDR3 vram then in real world use it's not going to be all that much of an improvement over the APU. Some might argue that at least it doesn't share ram, but that's of marginal real world value if the ram it uses is slow ram.