[SOLVED] CPU bottlenecking RTX 2080S? (ray-tracing, 1440p@165hz)

Aug 5, 2019
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Hi,

I recently upgraded my GTX 970 to an RTX 2080 Super, with that I also upgraded my main display from 1080p@60hz to 1440p@144hz (165hz OC). My CPU is the i5-8400, with a Dark Rock 4 cooler to support a planned future CPU upgrade. So with my new beefy GPU I decided to try Battlefield V with ray-tracing enabled, but this resulted in unplayable stuttering and what looked similar to "double vision". I've also had no luck in getting G-Sync to work on my verified G-Sync compatible monitor (https://www.asus.com/Monitors/TUF-Gaming-VG27AQ/), every full-screen game flickers when G-Sync is enabled, the internet shows no solutions for this other than updating drivers (which I have done).

Ultimately my question is: could all or some of these effects be caused by a CPU bottleneck? I remember people telling me that my CPU would be too weak to support 144hz+ properly in the first place.
 
Solution
Frankly, I am not sure what all the debate is about. The MINIMUM requirement for this game is an Intel Core i5-6600K, the recommendation WITHOUT ray tracing is a i7-4790 , and WITH tracing, a i7-8700, Get a better CPU, case closed.
Aug 5, 2019
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@NightHawkRMX When disabling RTX, the stuttering/double vision is gone. But the g-sync flickering is still an issue unless I go into windowed mode. And there are more moments where games can feel stuttery. I just really feel like if there are any issues now, it HAS to be the CPU because the GPU should be fine for all this.
 

rodrigoxm49

Great
Oct 13, 2019
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Use MSI Afterburner and keep the eye on GPU Usage. If it drops below 95% usage without any sync turned on, CPU is causing bottleneck. It's hard to believe that is your problem, since Ray Tracing ON, 1440p and maxed out settings generally keeps any GPU busy.

Abou flickering, what's your monitor device and which cable are you using?
 
Aug 5, 2019
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Use MSI Afterburner and keep the eye on GPU Usage. If it drops below 95% usage without any sync turned on, CPU is causing bottleneck. It's hard to believe that is your problem, since Ray Tracing ON, 1440p and maxed out settings generally keeps any GPU busy.

Abou flickering, what's your monitor device and which cable are you using?
Okay I will try that when I'm home.

My monitor is the https://www.asus.com/Monitors/TUF-Gaming-VG27AQ/ (in the post) and I use a DP 1.2 cable
 

zero_l0gic

Reputable
Aug 17, 2018
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Ok try to run a benchmark that is GPU intensive like Heaven and check the GPU and CPU usage if GPU is at 98+% and CPU stays low then the CPU isnt bottlenecking the GPU (any other result and something is wrong). Now the CPU is not best but it should be more then up to task in most games, but on Battlefield 5 expecialy with raytray could be little much for him.


  • Processor (AMD): AMD Ryzen 7 2700
  • Processor (Intel): Intel Core i7 8700
  • Memory: 16GB RAM
  • Graphics card (NVIDIA): NVIDIA GeForce® RTX 2070
  • DirectX: DirectX Raytracing Compatible video card
If your CPU reflects high usage with low GPU usage, you have a CPU bottleneck. Similarly, this means that the game is CPU dependent. Looking at the flip side, if your GPU loads are spiking while your CPU loads are at low levels, you have a GPU bottleneck.

And if both are high usage you have hardware that cant keep up with the task.
 

rodrigoxm49

Great
Oct 13, 2019
119
8
95
Ok try to run a benchmark that is GPU intensive like Heaven and check the GPU and CPU usage if GPU is at 98+% and CPU stays low then the CPU isnt bottlenecking the GPU (any other result and something is wrong). Now the CPU is not best but it should be more then up to task in most games, but on Battlefield 5 expecialy with raytray could be little much for him.


  • Processor (AMD): AMD Ryzen 7 2700
  • Processor (Intel): Intel Core i7 8700
  • Memory: 16GB RAM
  • Graphics card (NVIDIA): NVIDIA GeForce® RTX 2070
  • DirectX: DirectX Raytracing Compatible video card
If your CPU reflects high usage with low GPU usage, you have a CPU bottleneck. Similarly, this means that the game is CPU dependent. Looking at the flip side, if your GPU loads are spiking while your CPU loads are at low levels, you have a GPU bottleneck.

And if both are high usage you have hardware that cant keep up with the task.
Heaven is a only GPU benchmark, not a CPU demanding. I respectfully think this test will be not useful.
 
But that is the point, that is how you check for CPU bottlenecks. Answer to your question is no. You have a CPU that isnt up to the task that is the problem. Not that the cpu is causing the gpu to underperform.
What? How is a synthetic benchmark that barely uses the cpu going to allow you to make any meaningful observations about the cpu. I’m with the others, this won’t help.
 
You should try and check with MSI afterburner like others wrote, but I have a diferent question, How much RAM do you have ?

If the answer is 16GB, then I will first try and make G-Sync work properly (don't focus only on BF5 try with some other game too), and yeah, probably try with a better cable, atleast DP 1.4.

But as drivinfast247 wrote, BF5 is a very CPU demanding game so Im not surprised that your having some stuttering when pairing an RTX 2080 with a Core i5 8400 (which should only top around 3.7GHz on all cores).


Edith: I forgot, you can also try BFV on 1080p or 1440p with vsync on (and set on 60Hz) and see if still stutter.
 

zero_l0gic

Reputable
Aug 17, 2018
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What? How is a synthetic benchmark that barely uses the cpu going to allow you to make any meaningful observations about the cpu. I’m with the others, this won’t help.
That is how you check for bottlenecks
You should try and check with MSI afterburner like others wrote, but I have a diferent question, How much RAM do you have ?

If the answer is 16GB, then I will first try and make G-Sync work properly (don't focus only on BF5 try with some other game too), and yeah, probably try with a better cable, atleast DP 1.4.

But as drivinfast247 wrote, BF5 is a very CPU demanding game so Im not surprised that your having some stuttering when pairing an RTX 2080 with a Core i5 8400 (which should only top around 3.7GHz on all cores).
it is a cpu demanding game the developer say that you need i7 8700 for rtx. This isnt rocket science. No you cant run something good if you dont have the required hardware.
 
Aug 5, 2019
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it is a cpu demanding game the developer say that you need i7 8700 for rtx. This isnt rocket science. No you cant run something good if you dont have the required hardware.That is how you check for bottlenecks

This is useful information, thanks! I wasn't aware of the recommended specs (I should have checked..). I do wonder, why does CPU matter so much for ray-tracing? Isn't that purely GPU related? Either way a CPU upgrade was coming for me, I have decided on the i7-8700k for now (z370 chipset mobo).


If the answer is 16GB, then I will first try and make G-Sync work properly (don't focus only on BF5 try with some other game too), and yeah, probably try with a better cable, atleast DP 1.4.
Yes I've got 16GB 2400mhz DDR4 memory. What makes you think that DP 1.4 will perform better over 1.2 in this case? The internet says 1.2 should suffice for 1440p.
 
Yes I've got 16GB 2400mhz DDR4 memory. What makes you think that DP 1.4 will perform better over 1.2 in this case? The internet says 1.2 should suffice for 1440p.

It wouldnt be the first time something as "simple" as a cable would be guilty of the image issues you described. But if you are 100% sure and confident that your 1.2 DP cable is a of really good quality then forget about my comment. I can't be sure (probably no one can't) that the cable is, or not, too blame, Im just pointing out to a posible source of problem.
 

boju

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Displayport HBR2 copper cable is more than capable of doing 1440p 165Hz and 1.2 <> 1.4 DP should be compatible. If cable came with monitor or is a Vesa certified brand then it's most likely something else, driver perhaps or Nvidia's recent low latency mode inclusion. If there was something wrong with cable at high Hz, the monitor would blink black losing signal.
 

boju

Titan
Ambassador
Frankly, I am not sure what all the debate is about. The MINIMUM requirement for this game is an Intel Core i5-6600K, the recommendation WITHOUT ray tracing is a i7-4790 , and WITH tracing, a i7-8700, Get a better CPU, case closed.

Ray tracing is gpu dependant afaik. Without Ray tracing would require a faster cpu because more fps with this disabled = more cpu frame pre-rendering.
 
Aug 5, 2019
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Frankly, I am not sure what all the debate is about. The MINIMUM requirement for this game is an Intel Core i5-6600K, the recommendation WITHOUT ray tracing is a i7-4790 , and WITH tracing, a i7-8700, Get a better CPU, case closed.

To be fair the minimum for DXR enabled it says "i5-8400", the one I have now, I assume the minimum would be without any issues..