PC Graphics

[KrispyK]

Hi guys,

This is a re-hash of a question that has popped up before, but I've not found a clear answer on it yet, and equipment capabilities change over time, so in any case an updated answer might be instructive. I have just built a new PC with:

Mobo: ASUS TUF GAMING X670E-PLUS

CPU: Ryzen 9 7900X

GPU: Radeon RX 6800

RAM: 32GB DDR5

Windows 11 Pro

Monitor: Acer XV282K (3840 x 2160)

When I am gaming I can see that the onboard GPU is not doing anything. Can I increase my FPS (or perhaps graphics quality settings) by using both GPUs at the same time on the one monitor? If so, how? Does any potential benefit depend on the game being coded to use multiple GPUs (and so vary from game to game)?

Thanks in advance.

[Speedyblupi]

No, it is not possible to use the integrated GPU and graphics card together for the same task with this combination of hardware.

It is actually possible with some AMD APUs and graphics cards from about 10 years ago (called "Radeon dual graphics"), but it often didn't result in any increase in performance, because the latency penalty of communicating between the two GPUs usually exceeded the minor performance improvement from adding the extra performance of the integrated GPU to the graphics card. Games needed to be optimised to run on multiple GPUs in order to gain a significant amount of performance from dual graphics. I had an old laptop with 8650G + 8750M dual graphics, but most games actually ran better when dual graphics was disabled. AMD dropped support for dual graphics just a few years after introducing it, because very few game developers wanted to optimise for it.

However, it is sometimes possible to use an integrated GPU and graphics card for different tasks at the same time. For example, in some recording software, it is possible to use your graphics card to play a game, while using your integrated GPU to record and encode video of your gameplay. This can be useful for streamers and other content creators who want to ensure that all of their graphics card's bandwidth and computational power can be dedicated to running a game. An RX 6800 will typically lose about 5% of its gaming performance if you use its onboard video encoder at the same time.

[NotoriousPyro]

This is misinformation: https://community.amd.com/t5/gaming/amd-and-microsoft-advance-hybrid-graphics-for-gamers/ba-p/626332

I own a 9900X CPU and a 4090 RTX. Both different graphics manufacturers: NVIDIA and AMD

Super ultrawide monitor at 120hz 5120x1440 plugged into the motherboard.

iGPU set as primary device in BIOS

4090 set as secondary device

NVIDIA can see that it is no longer a primary display device. It sits idle in Windows when I'm doing nothing intensive. When I launch a game or 3D app that exceeds the ability of the iGPU to render at the desired FPS (120Hz), e.g. 3DMark, BOTH the iGPU and the dedicated GPU are in use. The rendering performance is higher than either alone and my benchmark score is just shy of the 79503XD (with its humongous cache and core count) and similar 4090 RTX.

[goodplay]

That article was about laptops using igpu & dgpu, so wouldn't call it misinformation.

[NotoriousPyro]

Not relevant since the technology is the same.

I never called the article misinformation. I said the poster was posting misinformation, i.e. The person I replied to.

However I'm not sure why you would believe or suggest that the technology in use in laptops to do this would not be the same technology in desktops... It's basically the same thing (a computer) but just a thin version...

https://devblogs.microsoft.com/directx/optimizing-hybrid-laptop-performance-with-cross-adapter-scan-...

Sorry if you werent able to understand that. 

[Speedyblupi]

The question is about using the integrated GPU and discrete GPU together to boost graphics performance, on a desktop PC with an RX 6800.

That article is about redirecting the output of a discrete GPU through an integrated GPU, which is a completely different concept. This is possible, but it doesn't increase performance relative to using the discrete GPU's own video outputs; in fact, it's slower. Nvidia's version of the same technology is called "Optimus". The technology exists for reducing manufacturing costs and power usage on laptops (as it doesn't require a MUX switch), and can also be useful on a desktop if you don't have enough video ouputs on the card (e.g. when gaming on mining cards), but isn't relevant to a desktop PC with an RX 6800 and a single monitor.

The performance gains described in the article are relative to an older method of sending a dGPU's output through an iGPU, which had a more complex pipeline and was more bandwidth-intensive, but the new "Hybrid Graphics" process is still slower than using the dGPU's output directly.

Please don't accuse me of misinformation based on sloppy research. Read your sources carefully and check whether they're actually relevant to the topic.

Also, regarding your claim "The rendering performance is higher than either alone", I don't see how that could possibly be true, considering that all you're doing by sending your RTX 4090's output through your iGPU, is adding a redundant step that wouldn't be necessary otherwise if you just used the 4090's output. How are you measuring the performance?

[NotoriousPyro]

Incorrect in saying it doesn't increase rendering performance... since Microsoft noted it does and I have noticed it in windowed mode in flip presentation mode... The desktop is rendered by the igpu and the game is rendered by the dedicated card.

You haven't provided a single source of your claims and yet you are asking me to prove my case? Lol

The article linked does not talk about a more complex pipeline, it talks about a streamlined pipeline (CASO) replacing the complex pipeline that is slow. 

How you can believe or claim it doesn't increase rendering performance when tasks are offloaded from the beefier tasks is beyond me.

If the author was trying to render in windowed mode, or multiple monitors, he would definitely notice an improvement... He asked would it improve performance in games, yes, yes it would depending on what you are doing (multi monitor / windowed).

https://devblogs.microsoft.com/directx/optimizing-hybrid-laptop-performance-with-cross-adapter-scan-...

I myself play a lot of games windowed. 

Try it yourself. 

[elstaci]

You can do something similar but with 2 or more GPU cards installed using AMD MGPU: https://www.amd.com/en/resources/support-articles/faqs/DH3-018.html

But in a desktop, as far as I am aware, you can't uses both IGPU and GPU card together as one GPU. In laptops, at least in the past, you can use IGPU and GPU together but that is not common any more.

[NotoriousPyro]

No, not rendering the same thing but the iGPU can be rendering several windows of 3D or the desktop or doing video decoding while the GPU card renders a more intense game.