Is bottleneck a myth?

[Irene ❤]

In the past, many experts claimed that CPU have to be as fast as GPU or it'd bottleneck performance.

Fast forward today with 5000 series, GPU is doing most of the work. It's all about higher version of DLSS, better scaling, AI frame render and high RAM to process them (up to 32GB in 5090). mid-range CPU have crazy fast speeds too, 14600K = 3.5GHZ (compared to 14900K = 3.2GHZ). Therefore mid-range CPU can fully deliver raw data, and high-end GPU can do more calculations.

Will a mid-range CPU today still bottleneck a high-end 5090?

[ˢᵈˣ FatCat]

It's always corporate agenda to spread fears

[r.linder]

Bottlenecks are undeniable but they're heavily overestimated, you should never worry about them until you get into something crazy like pairing a 5090 with a Celeron

[Coffee]

I'm not an expert but a streamer I watch regularly did an upgrade recently which demonstrated the effect of bottlenecks quite well. His system was a 14900k, 4090 and 64gb RAM. He had an issue with the Intel processor and had to underclock it a bit to get it to run stable from new. He decided to upgrade just the mobo and cpu to a 9800X3D and the rest of the system remained the same. His fps more than doubled doing this using all the same components. That's with a 4090, bottlenecks are real and the more powerful the gpu like a 5090 the more pronounced the bottleneck will be if the cpu is not up to par IMO.

[ᶻ𝗓𐰁]

You can see the bottlenecks with a metrics overlay. If your CPU goes to 100% and you start losing frames, then you have a CPU bottleneck.

[ˢᵈˣ FatCat]

Never trust influencer bro, they are always in bed with some brand

[Coffee]

Originally posted by ˢᵈˣ FatCat:

Never trust influencer bro, they are always in bed with some brand

He's not an influencer mate he's a small streamer with no sponsors who lives in the same city as me. He bought the parts from the same store I go to. I recommended he go there. It was just a recent example that came to mind.

[Chaosolous]

No, it's not a myth.

[_I_]

basically, if the gpu is not at 90%+ the cpu or something is holding it back

you cant look at cpu usage, since games do not always use all threads to max a cpu newer
even thread loads, since windows scheduler moves tasks around to balance core loads

[Ralf]

Originally posted by Irene ❤:

14600K = 3.5GHZ (compared to 14900K = 3.2GHZ).

You may want to do some research on this, because 14600K is 5.3GHz and 14900K is 5.7GHz

Originally posted by Irene ❤:

Will a mid-range CPU today still bottleneck a high-end 5090?

Mid-range? Even the best cpu out there(9800X3D) was holding back the 4090 let alone 5090, for example in Baldurs Gate 3, Elden Ring, Spider Man Remastered.

[Irene ❤]

Why would 5.7GHz bottleneck a 3D render? Is it not fast enough to send it raw data? : x

data (CPU) -> GPU 3D render -> display.

[Mad Scientist]

Is bottleneck a myth?

No.
It is not a myth.

If you want a perfect example of a bottleneck, play a modern AAA game with a high-end GPU with full details, minimum 1080p, and an FX-8350 CPU, that will do a lot to demonstrate the overall bottleneck effect that can happen with various hardware.

As many say, "your machine is only as fast as your slowest part".

[Alesta]

almost

[A&A]

It is rare for CPU and GPU to operate at their maximum advertised speeds while maintaining perfect synchronization in data transfer and processing.

And with DLSS frame generation, you can output more frames without requiring the CPU to calculate positions of the objects.

If you only play games, the comparison between i9 and i7 is very small, while with i7 and i5 it is tolerable.

[HIVEmind]

needs more hammers.

[C1REX]

Originally posted by Irene ❤:

Why would 5.7GHz bottleneck a 3D render? Is it not fast enough to send it raw data? : x

data (CPU) -> GPU 3D render -> display.

CPUs do a lot more than that. Data streaming and decompression alone can choke many CPUs causing unplayable stutters. Same for handling too many online players at once in some games.
Then you have Ray Tracing that is both: GPU and CPU heavy. Also VRAM heavy.
CPUs need to handle game engine, physics, NPCs, enemies AI, animations and much more.


Bottlenecks are real but often misunderstood.
Some stupid bottleneck calculators may tell you that you are GPU bottlenecked by 5% but won’t tell you that your horrible traversal and shader stutters are caused by your CPU. That your 1% lows are mostly caused by the CPU.