How to test for bottlenecks yourself?

[superfantastic]

I  would want to find out if my current rig has a bottleneck. I would like to learn how to figure this out myself. Does anyone know what method I can use?

 

When I play ac valhalla on mostly high settings, gpu usage is near 100% and cpu usage mostly between 30 and 40%. Does  this mean gpu is the bottleneck?

[Ankh Tech]

4 minutes ago, superfantastic said:

I  would want to find out if my current rig has a bottleneck. I would like to learn how to figure this out myself. Does anyone know what method I can use?

?

When I play ac valhalla on mostly high settings, gpu usage is near 100% and cpu usage mostly between 30 and 40%. Does  this mean gpu is the bottleneck?

what is the system

[SupaKomputa]

27 minutes ago, superfantastic said:

gpu usage is near 100% and cpu usage mostly between 30 and 40%. Does  this mean gpu is the bottleneck?

Yes

[Deli]

31 minutes ago, SupaKomputa said:

Yes

No. GPU is bottlenecked when its utilisation is 50%, but the CPU is 100%.

[Deli]

59 minutes ago, superfantastic said:

I  would want to find out if my current rig has a bottleneck. I would like to learn how to figure this out myself. Does anyone know what method I can use?

 

When I play ac valhalla on mostly high settings, gpu usage is near 100% and cpu usage mostly between 30 and 40%. Does  this mean gpu is the bottleneck?

no.

[GoldenAce]

1 minute ago, Deli said:

No. GPU is bottlenecked when its utilisation is 50%, but the CPU is 100%.

I think you misunderstood. The OP asked if his GPU was bottlenecking his PC, which would mean he was inquiring if he had a situation where his CPU was being bottlenecked. So @SupaKomputa is right in saying the GPU is the bottleneck. You probably got the two mixed up

[Dr0y]

To see if it's a gpu bottleneck just monitor your fps while playing with the setting you're playing at ... lower the graphical setting (not the resolution) to the lowest and if your fps increase then yes your gpu is bottlenecking. 

[Deli]

26 minutes ago, GoldenAce said:

I think you misunderstood. The OP asked if his GPU was bottlenecking his PC, which would mean he was inquiring if he had a situation where his CPU was being bottlenecked. So @SupaKomputa is right in saying the GPU is the bottleneck. You probably got the two mixed up

How often you see both CPU and GPU are utilised for 100% a the same time? My PC has a R5 3600 and 5700XT. Usually I see the CPU is only at 50-60% when gaming. Does it mean the 5700XT is the bottleneck?

I know someone has a 5900X and RTX3090. The CPU barely reached 50% during gaming. Does it mean the 3090 is the bottleneck?

 

[superfantastic]

46 minutes ago, Dr0y said:

To see if it's a gpu bottleneck just monitor your fps while playing with the setting you're playing at ... lower the graphical setting (not the resolution) to the lowest and if your fps increase then yes your gpu is bottlenecking. 

Alright so I did benchmarks. I normally  run the game on mostly very high setting with a few settings turned down to get closer to a constant 60fps. My average fps in the benchmark is 62 fps.

 

With everything set to the lowest option my average fps becomes 79. GPU usage remains near max, while cpu usage actually dropped by about 5% I think.

I saw a video of hardware unboxed that showed that there isnt a huge amount to gain in valhalla by turning all the graphics settings down unfortunately.

 

So do you think this could indeed mean the gpu is the bottleneck? My specs are the i7 9800x paired with the gtx 1070 btw, probably not unimportant info.

[Dr0y]

That feels like a gpu bottleneck yes ... if you want to shift the load to the cpu more you can try to play at a lower resolution ... but I would say that for that kind of game 60fps is probably good enough and for my part I would prefer visual quality over high fps ... it's not like a shooter game where you want the highest fps possible. 

 

 

[superfantastic]

Just now, Dr0y said:

That feels like a gpu bottleneck yes ... if you want to shift the load to the cpu more you can try to play at a lower resolution ... but I would say that for that kind of game 60fps is probably good enough and for my part I would prefer visual quality over high fps ... it's not like a shooter game where you want the highest fps possible. 

 

 

I agree. Sadly, average 60 fps does mean that it sometimes drops to below 40 fps too which is very noticable. Especially since I have a 144hz screen and I usually play games that can reach that fps. The main reason I want to find the bottleneck is because I want to upgrade to the point  where I can hopefully play cyberpunk 2077 at ultra settings without the fps ever dropping below 60, I'm hoping a 3080 will do that. Unless my cpu would bottleneck the 3080 then I have a bit of a problem...

[SupaKomputa]

1 hour ago, Deli said:

How often you see both CPU and GPU are utilised for 100% a the same time? My PC has a R5 3600 and 5700XT. Usually I see the CPU is only at 50-60% when gaming. Does it mean the 5700XT is the bottleneck?

I know someone has a 5900X and RTX3090. The CPU barely reached 50% during gaming. Does it mean the 3090 is the bottleneck?

 

There always be a bottleneck, it's near impossible to achieve the right balance. So don't worry about it.

100% CPU - CPU is the bottleneck.

100% GPU - GPU is the bottleneck.

 

In the scenario when 5900x + 3090, yes the GPU is the bottleneck (i assume it's running at 4K).

Because it cannot complete rendering frames before the cpu ask for new frames to be produced.

So the cpu is basically chilling out waiting for the 3090 to produce the 4k frames.

[superfantastic]

59 minutes ago, SupaKomputa said:

There always be a bottleneck, it's near impossible to achieve the right balance. So don't worry about it.

100% CPU - CPU is the bottleneck.

100% GPU - GPU is the bottleneck.

 

In the scenario when 5900x + 3090, yes the GPU is the bottleneck (i assume it's running at 4K).

Because it cannot complete rendering frames before the cpu ask for new frames to be produced.

So the cpu is basically chilling out waiting for the 3090 to produce the 4k frames.

 

But how does it work with games that don't use all cores? Let's say you have a very old 6 core cpu and the game you play uses only 1 core, thats a thing right? And lets say you pair this very old cpu with a 3090. The cpu just has to be the bottleneck but  it wont be at 100% right? Or does it not work like that?

[Zberg]

3 hours ago, superfantastic said:

I  would want to find out if my current rig has a bottleneck. I would like to learn how to figure this out myself. Does anyone know what method I can use?

 

When I play ac valhalla on mostly high settings, gpu usage is near 100% and cpu usage mostly between 30 and 40%. Does  this mean gpu is the bottleneck?

Usually to tell, run a game or benchmark, open HW info or watch in game stats if they have them on benchmark.  Watch utilization %.

 

You ideally want your GPU to BE the bottleneck (i.e. it is giving everything it has to push out max frames possible).  In this scenario it would be at or near 100%.  Since it is whats pushing the frames out, its the main component you want to be maxed.  

 

Your scenario looks great

[Zberg]

if you are going to run cyberpunk at 4k, I highly doubt the CPU will be an issue.  

 

Would get the biggest GPU you can to ensure 60 fps, but hard to guarantee it.  3080 would be my bet (or better)

[Dr0y]

8 minutes ago, superfantastic said:

 

But how does it work with games that don't use all cores? Let's say you have a very old 6 core cpu and the game you play uses only 1 core, thats a thing right? And lets say you pair this very old cpu with a 3090. The cpu just has to be the bottleneck but  it wont be at 100% right? Or does it not work like that?

correct it won't show 100% utilisation but the core it's using will be pinned at 100% the whole time ... that's why cpu bottleneck is hard to see cause it's not really as obvious as gpu when monitoring the usage. 

[superfantastic]

13 minutes ago, Zberg said:

if you are going to run cyberpunk at 4k, I highly doubt the CPU will be an issue.  

 

Would get the biggest GPU you can to ensure 60 fps, but hard to guarantee it.  3080 would be my bet (or better)

Could the cpu be an issue when I play it on  1080p? I know it's heavier on the cpu with lower resolution, but you think I could hit 144fps on 1080p if I get myself a 3080?

[Zberg]

it could be an issue at 1080p and high refresh (144 hz and above).  Thats the main scenario where I would think about a CPU bottleneck in the current times.  

 

Hard to know without seeing actual benchmarks for the game at 1080p.  I think it is fair to say that at 4k, and probably even 1440p you would be safely within a GPU bottleneck, but 1080p there's a chance the CPU could slow you down.  

 

I would also put money on a 3080 being able to get 144fps at 1080p, but please note, this is pure guessing.  I am a betting man, and I would put money on it, but I would suggest others wait on real benchmarks.

[superfantastic]

3 minutes ago, Zberg said:

it could be an issue at 1080p and high refresh (144 hz and above).  Thats the main scenario where I would think about a CPU bottleneck in the current times.  

 

Hard to know without seeing actual benchmarks for the game at 1080p.  I think it is fair to say that at 4k, and probably even 1440p you would be safely within a GPU bottleneck, but 1080p there's a chance the CPU could slow you down.  

 

I would also put money on a 3080 being able to get 144fps at 1080p, but please note, this is pure guessing.  I am a betting man, and I would put money on it, but I would suggest others wait on real benchmarks.

Alright, thanks for the answers man! Very much appreciated.

 

And all others too, if you happen to read this message! I know enough, I'm just gonna buy a 3070 or 3080 and we will see what happens. I will at least see some performance increase I'm sure of it.

[Dr0y]

 

 

 

[superfantastic]

7 hours ago, Dr0y said:

 

 

 

Alright so it's not really that overkill, especially if you use raytracing. But my cpu is not as good as the one used in the video, I have the i7 9800x. Only way to really find out what a difference that would make is, well, by testing it myself. Though, does anyone care to take a guess on how many frames I would lose compared to this video with my cpu?

[SupaKomputa]

9 hours ago, superfantastic said:

 

But how does it work with games that don't use all cores? Let's say you have a very old 6 core cpu and the game you play uses only 1 core, thats a thing right? And lets say you pair this very old cpu with a 3090. The cpu just has to be the bottleneck but  it wont be at 100% right? Or does it not work like that?

Easy, just pop up Task Manager check the cpu threads, it should tell you 1 core is at full load while the other is chillin.

So if you have 6 cores CPU it should be 1/6 (16-20%) utilization at all time.

Very old CPU paired with 3090 on a single threaded game will be a massive bottleneck.

BUT read this, bottleneck is not the end of the world, you still can play the game, but you will be limited with how much cpu "command" it can produce.

So in a way getting 3090 will still be better than using an older card.

At least you can use a higher settings for the same fps.