Reducing resolution reduces cpu usage in-game for me!

[COWZYOV]

Should this be the case? I always hear that resolution never affects cpu usage (unless maybe if you use an integrated gpu)...

I use a gaming laptop with an i5 7300hq cpu. Could that have something to do with it?

PS: yes, the dedicated gpu IS being used, before anyone asks

[Ogami]

Whoever told you that?
Its true that higher resolution is not as heavy on the CPU as on the GPU but there are still a lot of CPU calculations going on the higher the resolution is.
For example there are graphic effects like particles or even to some degree shadows that get calculated by the CPU and at higher resolutions those are more work and use more CPU power.

[nullable]

Yeah, the CPU isn't completely isolated in such a way where resolution never has any bearing on CPU usage. And it's highly variable between games (different engines). Even instances where the CPU isn't the primary component involved that doesn't necessarily make it wholly inconsequential either.

[mimizukari]

that's normal.

[COWZYOV]

Fair enough. I just always hear “if you’re cpu bottlenecked, raise your resolution, because it ONLY affects gpu of course😄”. Me, being cpu bottlenecked, only recently discovered this isn’t the case, and resolution actually makes a HUGE difference for me.
I was just wondering if it had to do with how laptops work, or if the guides on the internet are just dead wrong

[_I_]

for the igpu usage yes (if its causing the cpu to overheat)
but will not reduce the cpu usage itself

[COWZYOV]

引用自 _I_：

for the igpu usage yes (if its causing the cpu to overheat)
but will not reduce the cpu usage itself

So why does reducing resolution give me a huge fps boost even though I’m always cpu bottlenecked?

[_I_]

the intel hd is very weak igpu
lower res greatly reduces its igpu load

which can help prevent it from overheating the cpu causing throttling

7300hq
base freq 2.5ghz
turbo 3.5ghz
can throttle to under 800mhz

100% of 800mhz = 22% of 3.5ghz or 32% of 2.5ghz

[COWZYOV]

I’m quite sure I’m not getting any thermal throttle though; when I turn off vsync and uncap fps, cpu speed stays flush at 3.10 gigahertz—the maximum possible turbo boost level for all 4 cores on my cpu

And I have a dedicated gpu—the integrated gpu isn’t being used when gaming

[_I_]

the intel hd is is always used, its the only one attached to the display

the dedicated gpu writes to the intel hd frame buffer to be displayed
all post processing is done on the intel hd

[nullable]

引用自 AÀÁÂÄÆÃÅĀ：

Fair enough. I just always hear “if you’re cpu bottlenecked, raise your resolution, because it ONLY affects gpu of course😄”.

A lot of gamer wisdom is overly simplified and not overly well informed or applicable to anything beyond preferred or optimal configurations. And sometimes not very good ideas have hit critical mass and are repeatedly incessantly, without thought. The logic being is "it" must be true, otherwise it wouldn't be repeated so much... which has some obvious flaws.

[COWZYOV]

引用自 _I_：

the intel hd is is always used, its the only one attached to the display

the dedicated gpu writes to the intel hd frame buffer to be displayed
all post processing is done on the intel hd

This is something specific to laptops? Also, I take it the task you’re describing really isn’t graphically intensive, as the integrated gpu isn’t doing any 3D rendering whatsoever—it’s just pushing frames to the monitor once the dedicated gpu renders them.
That is, if I properly understood what you’re saying

[Snow]

In general, resolution doesn't affect CPU, but there are three things to consider.
1. If you switch from say 1920x1080 to 1280x1024 - this might let CPU produce more frames, as those resolutions have different aspect ratio. In most games you have ground below your FOV and sky/ceiling above it, but you have lots of objects to left and right, so by switching from 16:9 to 4:3 you decrease the number of on-screen objects, and therefore make CPU's job easier.
2. Various effects on consoles can be processed by CPU instead of GPU if console's CPU allows that. Say, PS3 had pretty weak GPU, but beefy CPU with 8 co-processors, so it made sense for developers to let CPU do extra job instead of GPU. PC version of GTA IV used CPU heavily to draw shadows, FF XIII being initially did cut your framerate in half if your combined CPU and GPU usage exceeded some point, etc. etc. So, while resolution doesn't affect CPU in most cases, there are enough exceptions to that.
3. Some games simply increase your field of view with the resolution. These days it's pretty rate, because most of the games are 3D, but old sprite-based games like Diablo 2 or Age of Empires had fixed size of the objects due to them being just sprites, and therefore resolution directly affected the number of on-screen objects.

Here[imgur.com] is my test of resolution/CPU in GTAV with CPU bottleneck. All the settings are the same, also the same FOV and same screen ratio. As you can see, high resolutions do put a bit of higher load on GPU and use more VRAM, which makes sense, but framerate and CPU usage stay within margin of error. From this we can conclude that resolution doesn't affect CPU in GTAV, and even if it does - the difference is negligible and nearly impossible to see.

[COWZYOV]

Yeah, I guess it depends on the game, as you said.
For me, I get +20 fps just by going down from 1080p to 720p in Destiny 2 (no benchmark, just stood still in the same position in the same spot for each test) and similar results in Star Wars Battlefront 2015 and Halo MCC. I’m pretty sure the same is true for Overwatch.
I did notice though, that games which don’t use exclusive fullscreen as well as games in windowed mode see no benefit whatsoever from reducing resolution...
Also, as for render scale, reducing that from 100% all the way down to 25% in Destiny 2 yielded no boost at all—in stark contrast to what happened when I reduced the actual resolution a relatively small amount.

[mimizukari]

obviously lowering resolution will make you gain more FPS as the GPU has to work less and it becomes more CPU bound.

[Bad 💀 Motha]

Well it does if the cpu suks, which yours does.

Laptops for gaming you should always consider the full performance i7 class option as even that is only as good as a Desktop locked i5