Hey all, so about three days ago I was playing DotA, and all of a sudden my FPS goes from 144 to 20-30! Like literally all of a sudden.

I tried restarting, nothing worked. I gave up and assumed it was a new patch issue. I downloaded the latest Nvidia drivers and launched DotA, it worked fine.

Yesterday I was playing, the same thing just happened. Not only did the FPS drop, but the computer is acting sluggish and slow from the moment I turn it on.

I've done full virus checks, spyware checks, tried system restore. I thought it was dust, I opened the PC, it was spotless, like brand new. There was a bit of dust on the bottom of the PSU filter, I cleaned that.

Any help would be appreciated.

Specs:

1) Case: NZXT H440 V2 Plus-W CA-H442W-M1 Matte Black/Red Mid Tower Case
2) Motherboard: MSI Z170A GAMING M5 (DDR4) USB 3.1 (LGA1151)
3) CPU: Skylake 3.40 GHz - i7-6700
4) PSU: Corsair CMPSU-CS850M 850W PSU 80 Plus Gold Modular
5) RAM: Kingston HyperX Savage 16GB (2 x 8GB) 240-Pin DDR3 2400 (PC3 19200) Desktop Memory Model HX324C11SRK2/16
6) SSD: Kingston SSDNow SM2280S3/240G 240GB M.2 SATA 6Gbps
7) MSI 1080 GTX
8) BenQ 24 inch GSYNC 144hz
9) Windows 10 Pro

And a UPS if that matters.
Did you check if anything is overheating and causing thermal throttling?
You're running DDR3 RAM on a system that's supposed to run on DDR4 or DDR3L.
How would I go about checking if it's throttling? Hwmonitor? Or is there a more comprehensive program?
Was the computer running hot? Fans running 100% for a while before?
dio wroteHow would I go about checking if it's throttling? Hwmonitor? Or is there a more comprehensive program?
Thermal throttling can happen at a low level in the hardware (BIOS, etc.). Just check if any temperature is abnormally high when that happens.
Do you play it in Fullscreen or Maximized Window?

Also do you have GSync enabled?

I suffered from the same issue till I disabled Gsync and set the display to Windowed
Georges00 wroteDid you check if anything is overheating and causing thermal throttling?
You're running DDR3 RAM on a system that's supposed to run on DDR4 or DDR3L.
I checked my Temps, they were all sub 35 degrees. As for my RAM, its DDR4, i mistyped it in the specs.

rolf wroteWas the computer running hot? Fans running 100% for a while before?
Not at all, the temperatures were shockingly low, and its slow from startup, not after an hour of gaming.
MrClass wrote
Do you play it in Fullscreen or Maximized Window?
Also do you have GSync enabled?
I suffered from the same issue till I disabled Gsync and set the display to Windowed
I tried both Full Screen and Maximized and they both had the same results. As for the Gsync, it IS enabled, but it has always worked as it should. why would i need to disable it all of a sudden?

I should stress on the fact that its not just games that have slowed down, its the actual PC itsellf, everything is just so much heavier...I mean opening File Explorer usually opens before i even think of opening it! Now it's just, slow.
Download CPU-Z and check if you're getting any CPU throttling. When you launch any game or benchmark, you should see the clockspeed rise up. If it stays low (e.g. 800MHz) then there might be a throttling signal from a sensor on the CPU or motherboard instructing the motherboard not to allow the CPU to raise its multiplier (base clock x multiplier = clock frequency).

ThrottleStop can also help with showing if any throttling flags are set. Make sure you're not running into the flag "BD PROCHOT".
yasamoka wroteDownload CPU-Z and check if you're getting any CPU throttling. When you launch any game or benchmark, you should see the clockspeed rise up. If it stays low (e.g. 800MHz) then there might be a throttling signal from a sensor on the CPU or motherboard instructing the motherboard not to allow the CPU to raise its multiplier (base clock x multiplier = clock frequency).

ThrottleStop can also help with showing if any throttling flags are set. Make sure you're not running into the flag "BD PROCHOT".
Thanks man, ill give it a shot when i get home and update you.
dio wrote
yasamoka wroteDownload CPU-Z and check if you're getting any CPU throttling. When you launch any game or benchmark, you should see the clockspeed rise up. If it stays low (e.g. 800MHz) then there might be a throttling signal from a sensor on the CPU or motherboard instructing the motherboard not to allow the CPU to raise its multiplier (base clock x multiplier = clock frequency).

ThrottleStop can also help with showing if any throttling flags are set. Make sure you're not running into the flag "BD PROCHOT".
Thanks man, ill give it a shot when i get home and update you.
Ok well this is a shocker. I launched CPU Z at startup, the Core Speed was 4,000 mhz, with a multiplier of 40. I launched Steam, speed dropped to 800 mhz. In parallel i ran AIDA64 and stress tested the CPU to 100% usage for about 5 minutes and it remained at 800 mhz.

image

Update. I launched BF4, the core speed remained at 800mhz.
Do a bios reset and a bios firmware update
dio wrote
anayman_k7 wroteHello, I found this thread speaking about the same problem you have
http://www.tomshardware.com/answers/id-3256302/problem-cpu-stuck-800mhz-z170a-gaming-motherboard.html#r18940958
Ill have a look at this. thanks

Meanwhile, here is the ThrottleStop image with the settings. As you can see the temps are low...yet stuck at 800 mhz.

http://i.imgur.com/b82xlSu.png
it is not a thermal issue, maybe a thermal reading issue from the board, or a faulty bios option that will make pc stuck in slow down, the main reason is the board, if the solutions listed did not work I recommend you RMA it if it is under warranty, I also do not recommend using the last option mentioned in the URL which is turning off the limit of the thermal throttle because it is risky in case someday the CPU cooler died
MrClass wroteDo a bios reset and a bios firmware update
Ill give it a shot and let you know. Thanks bois.
dio wrote
MrClass wroteDo a bios reset and a bios firmware update
Ill give it a shot and let you know. Thanks bois.
WARNING, DO NOT UPDATE BIOS FROM WITHIN WINDOWS

There is a high risk that you will brick your board (just like I did before), download the bios and place it on usb, flash it from the BIOS menu MFLASH
anayman_k7 wrote
dio wrote
MrClass wroteDo a bios reset and a bios firmware update
Ill give it a shot and let you know. Thanks bois.
WARNING, DO NOT UPDATE BIOS FROM WITHIN WINDOWS

There is a high risk that you will brick your board (just like I did before), download the bios and place it on usb, flash it from the BIOS menu MFLASH
Thanks for the warning, will do!
MrClass wroteDo a bios reset and a bios firmware update
Okay, I just finished resetting the BIOS as well as updating its latest firmware. No luck. Im still stuck at 800mhz with sluggish response.

What can I do next?
Maybe a faulty thermal sensor in the motherboard.
Is it still under warranty? Can you RMA it?
dio wrote
MrClass wroteDo a bios reset and a bios firmware update
Okay, I just finished resetting the BIOS as well as updating its latest firmware. No luck. Im still stuck at 800mhz with sluggish response.

What can I do next?
In the meantime, disable BD PROCHOT through ThrottleStop. This happened to my laptop (Dell XPS 15 9550) as well and the only solution such that the laptop is usable is to use ThrottleStop.
yasamoka wrote
dio wrote
MrClass wroteDo a bios reset and a bios firmware update
Okay, I just finished resetting the BIOS as well as updating its latest firmware. No luck. Im still stuck at 800mhz with sluggish response.

What can I do next?
In the meantime, disable BD PROCHOT through ThrottleStop. This happened to my laptop (Dell XPS 15 9550) as well and the only solution such that the laptop is usable is to use ThrottleStop.
Ok boys, here's the update.

After extensive research my problem seemed to have narrowed down to two possibilities.

1) Faulty motherboard sensor

2) "SlowMode" on the Z170 is bugging out after 6+ months of use

I checked online whether people were having a problem with the actual switch regarding the SlowMode, and they were. Apparently sometimes it turns on on its own without you having to switch it. I switched it on and off several times while the core speed was at 800mhz, after a restart or two, my core speed jumped back to 4000mhz. I gamed, opened up a lot of programs, it stayed at 4000. It seems to have done the job.

If it does go back to being throttled, I can either return the board to PcandParts or disable Intel Adaptive Thermal Monitoring (which I don't want to do)

So far so good. Thanks for all your help guys!