Is my i5 6600k bottlenecking my R9 390?

[Geroximo]

Hey guys,
I am running the following system:
Intel i5 6600k @ 3.9Ghz BoostClock
Sapphire R9 390 8GB
16GB Corsair DDR 4 RAM
ASUS ROG Maximus VIII Ranger Z170
650W Corsair PSU
500GB Samsung 850 EVO
Windows 7 Home Premium 64bit

Following problem:
I am getting major fps drops in Overwatch (144fps, Medium settings, 1080p) while running the i5 6600k at stock boost clock of 3.9GHz
GPU: 70% usage, 64 degree celcius
CPU: 100% usage

When I overclock my i5 6600k to 4.4Ghz, the fps drops are far less noticeable.
GPU: 80-90% usage, up to 70 degree celcius
CPU: 100% usage

Now this would lead me to the conclusion, that the processor is bottlenecking the GPU, because the higher the CPU clock, the higher the GPU usage and temps ...

but is that really the case? How can the latest generation i5 be already stressed out with such an undemanding game like Overwatch?

Does anybody experience the same issue and can confirm or deny this bottleneck?

Thanks

 

[Supernova1138]

If you're shooting for really high framerates eg. 144FPS constant, i5s can become a bottleneck in some games, and it may be beneficial to overclock or get an i7. Overwatch does benefit from hyperthreading, so getting a 6700k might be worth it if you want 144FPS constant really badly. Thing is, there are some games where even the i7 6700k can't hold 144FPS constant even with an overclock. This might wind up becoming an issue in the future for people with 144Hz displays, where you may have to accept some framerate drops as CPU technology has more or less hit a brick wall at this point and games are only scaling across larger numbers of cores at a snail's pace. Overwatch doesn't look all that demanding graphically, but it can get quite CPU heavy if you want really high framerates.

Generally speaking, when people say the i5 isn't a bottleneck, they're talking about 60Hz displays and usually to people on a budget where they can get a high end GPU or an i7 but not both, in which case the i5 with the better GPU is pretty much always better than the i7 with a weaker GPU when it comes to gaming at 60Hz. If you have a 144Hz monitor, it might be different depending on what you're playing and what GPU options you're looking at.

 

[kasol kay]

Could be a "Windows Bug". Go to your Task Manger, then hit the Performance Tab, then Resource Monitor, then click CPU, and see what is taking up all that %Usage.

You could also try Overclockin'.

 

[tps3443]

Im running a gtx 1080 over clocked, with my 6600K @4.61.

In Overwatch EPIC graphics, everything maxed out, 100% resolution slider at 1080P my avg fps is 200-260. Minimum fps is 168, GPU utilization stays at 99% so, its not bottlenecking my gtx1080. I doubt its doing it with a 390

 

[Geroximo]

Hey guys,
thank you for your replies.
I found the solution.
My computer was searching for windows updates in the background, which consumed so much processing power that my GPU got bottlenecked.
Stopping windows update and or increasing the process priortiy of Overwatch.exe fixed the problem.