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WeirdGamerAidan OP t1_j6ljzn3 wrote

Reply to comment by kanavi36 in ELI5: Why do computers need GPUs (integrated or external)? What information is the CPU sending to the GPU that it can't just send to a display? by WeirdGamerAidan

In that case why does windows recognize them separately in task manager (with separate status windows and everything)?

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ThatGenericName2 t1_j6lmf86 wrote

It doesn't, the person that replied to you is incorrect.

Some CPUs have a low power GPU integrated into it, hence Integrated GPU, and not all CPUs have them.

These Integrated GPUs are very weak and are meant for the bare minimum of graphics processing, enough to draw the interface of a word document or other programs and that's about it. Attempting to do anything complicated such as 3D rendering, even really simple ones will start to strain it.

Despite this these Integrated GPUs are still much better at graphics processing than software renderers that actually use the CPU.

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salvodan t1_j6m0a82 wrote

And before integrated GPUs or even discrete low-powered GPUs the User Interface was rendered using the CPU itself (software rendering). This was a long time ago, back in the old days of text interface in CGA and simple 2D sprites. (1980s)

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Bensemus t1_j6nrvtz wrote

This is more true of Intel iGPUs. AMD APUs were actually designed for light gaming as their integrated GPUs actually had some power.

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AdiSoldier245 t1_j6lp924 wrote

An integrated GPU is a seperate GPU inside the processor, it's not using the CPU to compute graphics. If you look at internal layouts of a processor with an iGPU, you'll see the GPU as a seperate object. So displaying doesn't slow down the CPU part of the CPU(that much, there could be bandwith issues).

A discrete GPU is what goes into a pcie slot and is a GPU outside of the processor. This is what most games require as the iGPU is mostly only enough for displaying and maybe processing video.

Software rendering is using the CPU cores themselves to do graphics tasks.

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kanavi36 t1_j6lnygb wrote

After posting my reply I considered I might have been incorrect in what I assumed from your comment, so I apologise. I assumed you were talking about when a game doesn't select the dedicated graphics and defaults to the integrated graphics on the CPU, which is quite common and would lead to low frame rates. I've never actually heard of a CPU skipping the integrated graphics and directly rendering a game, which sounds interesting. What does it appear as in your task manager?

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WeirdGamerAidan OP t1_j6miuo3 wrote

When it happens, as soon as I load up the game cpu usage skyrockets to 100 and gpu stays low, and the game runs at like 1 fps. Happens the most with Roblox and Superliminal. I usually have to reload those games several times before it works properly.

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WeirdGamerAidan OP t1_j6miy85 wrote

I don't recall if in task manager it shows it's using the gpu

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kanavi36 t1_j6o4db3 wrote

Interesting, and also quite strange. What CPU do you have?

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WeirdGamerAidan OP t1_j6oevbx wrote

Uuh I think it's an i7 but I'm not at home rn so I can't check. I'll try to find the laptop online and see what the cpu is. If it helps task manager displays the integrated graphics as "intel hd graphics 620"

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WeirdGamerAidan OP t1_j6ogx1l wrote

Online search was partly successful. It is either an i7-7500U, i5-8250U, i5-7200U. Iirc I think it's the i5-8250U

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TheSkiGeek t1_j6p31rr wrote

“Integrated graphics” or an “integrated GPU” these days almost always refers to a small(er)/weak(er) GPU that is included in the CPU itself.

From the perspective of the operating system, a ‘discrete’ GPU and the ‘integrated’ GPU are both rendering devices that it can access. In a laptop with discrete graphics, both of these are usually able to output to the built in display, so a game or other application can choose to render to either one. That’s usually where you see things getting confused, as the BIOS or OS might be configured with the integrated graphics chip as the first/default rendering device.

It’s also possible to do pure software rendering using only the CPU. Nobody actually wants to do this these days for real time applications, since it is painfully slow. But it is an option.

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