HUGE random FPS drops. "Perfcap Reason: Util"

Can anyone offer a suggestion as to what might be causing the following situation to happen? I've been trying all sorts of things for days, trying to narrow this down, and I can't figure out how to fix this.

I have a 17 R2 with 980M.

Problem:
Sometimes when playing a 3D game with the Nvidia GPU, there are periods when the game's frame rate drops suddenly to a slideshow. This happens randomly, but on average it occurs approximately once every 5-20 minutes of gameplay. When the problem occurs, the frame rate is terrible for about 60-120 seconds or so (the length of the problem is also random), then miraculously the frame rate goes back to normal. While the problem is occurring the game is essentially unplayable due to the massive amount of control input lag making mouse selections nearly impossible.

This isn't because I've reached a moment in the game where there are extra graphics or draw distance or effects on the screen. To the contrary, the problem occurs completely independently of what I'm doing in the game or how complex the graphics are in the game at the time. Also, I have noticed that the problem occurs in different games, as long as they use the Nvidia GPU. Though the degree to which the game is affected by the problem varies. Games which do not use the GPU as heavily are not as problematic when the issue occurs, though, the issue does still occur, because I can see it happening with GPU-Z.

If I run the Techpowerup GPU-Z utility, I can clearly and unambiguously see that this is caused when there is a PerfCap of reason: Util occurring. Also, the GPU clocks get downclocked, the voltage gets reduced and the GPU load gets reduced to something like 20/30%.

I've done some googling, and from everything I've read, this PerfCap reason occurs because the Nvidia drivers think that the GPU is not being utilized, and therefore is reducing the voltage to the GPU in an attempt to save battery life on the laptop (despite the fact that I'm plugged into AC power at the time).

I've tried lot of things and nothing was successful. (It's not a temp issue, I've also clean reinstalled drivers, I've set all the power management options on the laptop to "performance", I've disabled any background program, well, almost everythinh)

I've contacted Dell's support and they know NOTHING.

Any sugesstions here? I'm getting REALLY crazy. I've even tried the new vBios Prema has posted, without success.

Thanks in advance.

 

Hmm, let me take a guess... You have the 180W PSU?

It's insufficient for the 980M. You need the 230W/240W PSU.

http://www.dell.com/support/article/us/en/19/SLN295814

 

That'd have been my first guess, but I've been using the 240W PSU for more than 5 months now. So that's not the problem :/

 

Run XTU in the background while gaming and monitor CPU temps, CPU speed, package TDP & thermal throttling.

See if you can spot your CPU speed dropping that coincides with the frame drops.

Maybe the CPU is throttling back and isn't able to feed the GPU quickly enough!

If you are on BIOS A00 make sure you restart before gaming in case you are being affected by the CPU TDP throttle bug after resuming from sleep!