Video and Games Lag at Fullscreen

[Rukongai]

I noticed a couple of days ago that my computer was lagging whenever I played a game in fullscreen. I couldn't find of any way to fix this problem so i decided to format my computer. After doing that and downloading a movie I noticed that whenever I was watching the movie in fullscreen in a video player such as VLC or GOM the video was lagging the same way that it did with the games before. However when it was not in fullscreen the movie played just fine. Also playing the movie with the default Windows 10 video player didn't seem to cause any problems neither in fullscreen nor in windowed. I have yet to try a game out after the format.

So what could be the cause of my problem? Since the format didn't fix the problem I'm guessing it should be hardware related but I don't know what it could be. It definately is not due to computer underpower since I got a pretty beefy PC and it used to run everything just fun. I do not remember doing anything before it started causing this problem. Disabling hardware acceleration in the video player settings didn't fix the problem either.

Computer Specs:
CPU: Intel Core i5 6600K(Overclocked at 4.5GHz)
MOTHERBOARD: ASUS Z170I Pro Gaming
RAM: G.Skill Ripjaws V 16GB(2x8GB) DDR4-2800MHz
GPU: Sapphire Radeon R9 390 8GB Overclocked w/ Backplate

All drivers are up to date since today 19th of May 2017.

Thank you for your time and help. 😀DD

 

[faalin]

what cooler are you using on the cpu? what temps are you getting? did you do any stress testing to make sure the OC is actually stable?

 

[Rukongai]

what cooler are you using on the cpu? what temps are you getting? did you do any stress testing to make sure the OC is actually stable?

I have already done all that my OC is perfectly stable I have run AIDA64 for over 12hours plus the amount of gaming I have done over the last year have proved that it's stable. Even if it wasn't I don't think that would be a problem since when watching Videos the CPU is not even hitting 30% load. I am using a Corsair H100i v2 240mm AIO on the CPU and my temps range anywhere between 23oC idle to 65oC extreme max load.

 

[Rukongai]

The problem seems to go away when I run my Computer from the CPU Graphics which would probably lead to a GPU problem. Let's hope it just needed a reseat cause GPUs are expensive!

 

[Rukongai]

Well then it definately is a GPU problem since it doen't work even after reseating the GPU. Well, I'm fuked.

 

[faalin]

underclock the card back to factory settings and see what happens. What make and model PSU do you have.

 

[Rukongai]

underclock the card back to factory settings and see what happens. What make and model PSU do you have.

The GPU is factory overclocked however I will download MSI Afterburner and try to underclock it and see if that changes anything. My PSU is a Corsair RM750x,

Underclocking the GPU didn't work.