That's awful!  Im no rockstar but, sounds like its throttling down.  MayB find someway to control the fans on the 1070,

check out your power plan etc and your cpu mod (OC).  We cannot control the cpu fan that I know about..However that's quite a drop to blame the cpu outright lol, U could go to task manager and set the priority (admin control) of the games executable after u launch it, set to high not highest then any background apps are less important to the cpu . 

  If the game files load to memory ok, then they should noe be exceeding 16gb,  but u could check your available PageFile  ( control panel/system/advanced/virtual memory) you will see manual and automated options, they say to set this to be 1.5 times the size of your RAM installation.  18-24gb probably in your case..this way if your RAM is tapped out, the game temporarily writes to your harddrive... 

hey my Friend. you can't catch a Break do you?

as dbrewster already mentioned it's probably due to Overheating. you can Download HWMonitor, run it in Background then launch your Game in Window Mode and watch the Temps. if the CPU Temp is reaching 90 - 95 °C or  the GPU more then 84 °C, then your Laptop is Overheating and Throtteling.

does your Laptop have Eye Tracking Feature? the Software can cause similar Issues.

yeah it's an alienware 15 r3 it has the eye tracking lite version. So my temps I noticed from Alienware Command  Center that the line which describes the temp is very close to 100° it was like only one square away from 100°. And while I played the eye tracker was turned off. I mean like I clicked on the icon inside the bar and turned switch from on to off. I don't know if it keeps on having some background proccess running even when it is turned off. And since I set the paging to "Managed by the OS" I didn't encounter any crashes, just the fps going down suddenly. (And one question out of cuiriosity, now my PC has 16GB of ram and the GPU has 8GB of it's on memory, why does each time i play the game the ram reach like 54% of it's usage?)

haha yeah... wish I could catch break! Still mad at their poor customer support! And we are talking about Dell!

Hm... I think I'll just have a technician from Dell do that for me. Even though it's been less than a month since they came to change my motherboard and apply the paste.

almost 100 °C is very likely what causing the FPS Drops. you should probably re-paste the thermal Paste. buy some Arctic Silver 5 Thermal Paste and watch some "How To" Videos on YouTube.

last Week someone complained about System Instability and we found some Errors in the Reliability History pointing at Tobii Software. if you want go to the tobii.com Website and Download the latest Software Version for your Model.

now about the RAM Usage. when playing Games both the CPU and GPU are using RAM. the GPU is using the 8 GB GDDR5 and the CPU is using the 16 GB DDR4 RAM. it's normal. nothing to worry about. i have 2,9 GB Usage right now and it's only used by Windows and Firefox.

if they do that for you then sure, why not. but you will need to learn it eventually.