Best way to tell if my CPU is the new bottleneck

[ElCuco68]

...now that I've got a watercooled 1080Ti? I'm currently using an AMD FX-8350, and while I know that this is a mismatch, and I definitely need to upgrade (to the i7 8700k), I'm wondering if the 8700k would make a drastic, very noticable difference, or not enough of one to justify not waiting a few months to a year to upgrade (CPU and MB)? I'm using an Oculus Rift.

[Tinkickef]

Windows 10. Task manager is a powerful tool for cross checking performance.

 

First stop.

Go into task manager / performance and look at GPU utilisation and CPU utilisation graphs. GPU should ideally be close to 100%, but I'd live with 80%. The higher the better, it means it's getting the info to get the frames out.

 

Over 90% and I would be happy. This is a good initial indication. My 980TI running at stupid barely stable overclock hovers around 98% utilisation. Vram size is preventing 100% as it hits the swap file occasionally.

 

Be interesting to see what happens when my new 2080TI arrives. I expect it to fall like a rock. I'm hoping for the 80% but time will tell and I'm being optimistic. Less than 75% and it means I'm throwing money down the drain if I don't upgrade the CPU to get the optimum performance I bought the card to provide. I won't be getting anymore performance than a 1080TI could provide.

However, I am hoping we see Vulkan multithreading sooner rather than later and hopefully, I can then save a penny and my marriage by not having to change my CPU, RAM and mainboard.

The central heating kicks in whenever I mention the 2080 to the missus. Gets a bit frosty. I see PC parts for my hobby, she sees holidays in the sun for the same price. I digress..

 

CPU Performance.

 

 

CPU performance graph should be well below 100%. I see around 15% to 18% typically in DCS on my OC i7 4790K.

However, DCS uses just a couple of cores on a multi core cpu, and this is not even using two cores properly, but bouncing back and forth between the two, so this is not the full story.

If you have reason to suspect core overload, Right click the performance graph, click change graph, click logical processors. This will give the performance of each core separately.

 

If none are hitting 100% consistently, you are not bottlenecking.

Edited August 28, 2018 by Tinkickef

[BitMaster]

Install MSI Afterburner, set the OSD and play.

 

 

If GPU usage is less than 98-100% your CPU lags behind. it should read CONSTANT 98 or 99%.

 

 

The less you have, the more a new CPU will help.

 

 

This all, is HIGHLY RES & LOD bound.

[ElCuco68]

I did this, and both CPU (all cores roughly the same) and GPU stayed between 30-40% (!). Not at all what I was expecting. DCS never went above 28 fps while flying; looking at ground at low altitude brought it down to about 20-22 fps. CPU went up to about 65 degrees C, at 4.61 GHz.

[jaznit]

Windows 10. Task manager is a powerful tool for cross checking performance.

 

First stop.

Go into task manager / performance and look at GPU utilisation and CPU utilisation graphs. GPU should ideally be close to 100%, but I'd live with 80%. The higher the better, it means it's getting the info to get the frames out.

 

Over 90% and I would be happy. This is a good initial indication. My 980TI running at stupid barely stable overclock hovers around 98% utilisation. Vram size is preventing 100% as it hits the swap file occasionally.

 

Be interesting to see what happens when my new 2080TI arrives. I expect it to fall like a rock. I'm hoping for the 80% but time will tell and I'm being optimistic. Less than 75% and it means I'm throwing money down the drain if I don't upgrade the CPU to get the optimum performance I bought the card to provide. I won't be getting anymore performance than a 1080TI could provide.

However, I am hoping we see Vulkan multithreading sooner rather than later and hopefully, I can then save a penny and my marriage by not having to change my CPU, RAM and mainboard.

The central heating kicks in whenever I mention the 2080 to the missus. Gets a bit frosty. I see PC parts for my hobby, she sees holidays in the sun for the same price. I digress..

 

CPU Performance.

 

 

CPU performance graph should be well below 100%. I see around 15% to 18% typically in DCS on my OC i7 4790K.

However, DCS uses just a couple of cores on a multi core cpu, and this is not even using two cores properly, but bouncing back and forth between the two, so this is not the full story.

If you have reason to suspect core overload, Right click the performance graph, click change graph, click logical processors. This will give the performance of each core separately.

 

If none are hitting 100% consistently, you are not bottlenecking.

 

So do you mean that my level of CPU and GPU usage means that my CPU is bottle-necking my GPU?

 

I had always thought unless the CPU was flat lining at 100% it's not impacting the GPU... but reading the above I am being restricted because of the CPU?

 

Jeff

[Tinkickef]

So do you mean that my level of CPU and GPU usage means that my CPU is bottle-necking my GPU?

 

I had always thought unless the CPU was flat lining at 100% it's not impacting the GPU... but reading the above I am being restricted because of the CPU?

 

Jeff

 

You are on 92% average, but hitting 100% regularly, so your CPU is likely bottlenecking your GPU slightly. DCS uses just a couple of cores, and that graph is showing your entire CPU which has 4, so a single core in use would be at 100% permanently. Right click graph, select "change graph", select "all logical cores" and you will be able to make a better judgement of individual core performance.

It would also be interesting to see what the Vram utilisation is like. To get better GPU utilisation figures, if you are using VR, you could try upping the pixel density, but if like me, your Vram is maxing out and hitting the swap file, this will affect your figures.

You would benefit from shutting down some background processes in task manager.

 

All in my limited view of course.

Edited September 1, 2018 by Tinkickef

[Tinkickef]

I did this, and both CPU (all cores roughly the same) and GPU stayed between 30-40% (!). Not at all what I was expecting. DCS never went above 28 fps while flying; looking at ground at low altitude brought it down to about 20-22 fps. CPU went up to about 65 degrees C, at 4.61 GHz.

 

 

All sorts of strange things happen, DCS primarily uses one core for physics ect and hits a second for audio, but that's not the full story.

The CPU will bounce the load around all the physical cores to maintain thermal stability, yet still still only using a single core performance at a time.

Then there is accessing shared caches ect, the DCS core may be idling a lot waiting for information to process because the cache is in use providing info to other processes.

 

When we start talking about L3 caches and stuff, this is where I bow out. It makes my head hurt and others far more knowledgeable than I would be better taking over.

[Tinkickef]

ElCuco68

 

I see what you mean now. I left TM running in a mission to see what you were talking about.

 

Very odd. Either my CPU is easily coping with DCS or I'm seeing some sort of threading going on.

 

Not what I was expecting to see. Overall utilisation 15%. Logical core 00 at 30% and core 07 at around 35 - 40 % GPU at 100% (VR) The figures did not change significantly even when the AIM120 was in flight.

 

Perhaps someone more knowledgeable than I can say what is happening. I either have far more overhead to run my new 2080TI than expected, or something is awry. Only other thing in my limited knowledge is the CPU is switching core 0 and core 7 very rapidly for thermal management.

 

 

 

Settings (Oculus Rift).

 

 

 

Edited September 1, 2018 by Tinkickef