Hello,
 
So I will preface this post by stating I am not extremely savvy when it comes to PC parts as I recently started learning how to build/replace parts in a PC. I bought a pre-built PC in 2017. It had a GTX 1060 and I recently bought a second hand 1080TI SC2 that was upgraded into a hybrid kit by the previous owner.  Here are my current specs:
 
PSU: Corsair RM750x
MOBO: MSI B250M Bazooka
CPU: Intel Core i7 7700 (Non-K)
GPU: EVGA GeForce GTX 1080TI SC2 Hybrid
RAM: 16 GB of Corsair RAM clocked at 2200 MHz
Storage: Intel SSDPEKKW128G7 M.2 SSD and Toshiba DT01ACA100 1TB HDD
 
Upon installing the card into my rig last week, I installed the latest drivers and it was working like a charm. I typically play R6 Siege, and while on my 1060 I was getting 110fps on average, my 1080TI was averaging 180fps. A dream and I loved it.
 
This past Sunday, I gamed for about 4 hours, took a break to eat and watch a Yankee game, and when I came back to play another round of Siege, my frames were sitting around 70-80fps. Hard reboot of the PC to no avail. My first instinct was to check temps: around 40°-45°C so that can't be it. I'm using NZXT CAM and GPUZ to monitor performance and I noticed that the load was previously sitting around 60-65% when the card was working properly, whereas now it's hitting max load, 99%, with the same settings. Very strange. The card is clocking right at 1480MHz at base, and in-game, it's boosting to 1930-1950MHz, so there doesn't seem to be an issue there. I called EVGA for support; they recommended I perform 3DMark FireStrike benchmark to see how the card is performing. Here are those results:
 
3dmark . com /3dm /38286167?  (can't post full URLs yet)
 
After that, I decided to run a different game to see if it was indeed my GPU underperforming, or if it was Siege. Ran Insurgency: Sandstorm, same result.
 
I then used DDU to uninstall the current drivers and reinstall. Nothing.
 
I searched for answers and found an old forum: forums.evga . com /HELP-Gtx-1080-ti-performing-absolutely-terrible-m2725968 . aspx
This person had incredibly similar issues with very similar specs, Core i7 7700k, GTX 1080TI SC2 also in Hybrid Kit. His issue was resolved by deactivating a slow mode switch on his MOBO, but I don't think I have such a switch on mine, and I'm a total noob when it comes to doing anything in my MOBO Bios. The last person I spoke to from EVGA suggested I flash my MOBO to see if that helps, but I'm not quite sure how to do that or what adverse affects that would have on my PC.
 
I recently bought some cable extensions to match the theme of the PC as well as an EVGA Powerlink and a CoolerMaster 90° 24 Pin extension to make things cleaner; Mind you, I installed these components the day before this issue occurred. Before that, I had everything plugged directly into the PSU. I highly doubt any of this is causing a problem, but it's worth noting. I'm assuming if these were causing a lack of power, the PC wouldn't boot properly... again, worth noting.
 
So here I am. Any and all help is appreciated.

bcavnaugh
Welcome to the Forum


 
 

I see that my card is slightly under your benchmark results, assuming your card is perhaps OC. Any idea why the physics score is so low on mine?

Sorry, I see my typo. It's a 1080TI SC2 hybrid. I'll fix that

bcavnaugh

mjtv.-

bcavnaugh
Welcome to the Forum


A 4 Core CPU for the most part is why maybe.
Your card is this? GPU: EVGA GeForce GTX 1080 SC2 Hybrid or GTX 1080 Ti SC2 Hybrid?

I see that my card is slightly under your benchmark results, assuming your card is perhaps OC. Any idea why the physics score is so low on mine?

A 4 Core CPU most likely.
Heat will reduce your Graphics Card and it is Summertime so this could be the cause or the NVIDIA Driver Version.
Run the Normal Time Spy and post your link without the https://

www. 3dmark .com/ 3dm/ 38301333?
here are the TimeSpy benchmark results
 
[Edit: had to break up URL again, sorry]

Your CPU is what is dragging your score down as bcavnaugh has suggested. 

bcavnaugh


Still shows the CPU being the bottleneck.

rjohnson11
Your CPU is what is dragging your score down as bcavnaugh has suggested. 

Yeah, I do see that. However, I don't think that's the issue with respect to the sudden drop in performance in-game. As I stated in the OP, my average framerate was sitting in the 180s. Now, I'm getting around 75fps average without me touching anything.

Sajin

mjtv.-
I recently bought some cable extensions to match the theme of the PC as well as an EVGA Powerlink and a CoolerMaster 90° 24 Pin extension to make things cleaner; Mind you, I installed these components the day before this issue occurred. Before that, I had everything plugged directly into the PSU. I highly doubt any of this is causing a problem, but it's worth noting. 

Time to plug everything back into the psu directly.

So removing the Powerlink ONLY resulted in the card performing significantly better. I then decided to plug everything into the PSU and performance then remained the same, so I know it wasn't the cable extensions or the 90° 24 Pin adapter causing some sort of issue. Perhaps its a faulty Powerlink? Anyway, guess I'll be returning it.
 
Now that I know my CPU is bottlenecking the GPU, that's the next thing on my list of things to buy! I'm seeing my FPS count back in the 180s and even 200s, but my lows are dipping below 144 which is defeating the purpose of buying this card.