After 2 years of ownership, I finally have a laptop that works as it should, and the solution is surprisingly simple despite the difficult in trackingdown the issues.
Ultimately, it was a 2-pronged approach with tweaks to both hardware and software. Let's start with the hardware. It's simple, and needs to be done:
The cooling system clogs up with dust, reducing its efficiency considerably. If your laptop fans are running more than they should and you haven't cleaned the fans before, now it a good time to do so. There are plenty of youtube videos stepping you through the process.
While you have the back off the laptop, locate the SSD. It has a silicone thermal pad (That probably came off with the case) to keep it from overheating. These pads are designed to efficiently transfer heat, but my SSD has a large insulating sticker on it. Simply removing that sticker before reassembling the laptop will keep the SSD running a lot cooler.
Optional - locate the SSD heat transfer pad on the outer case, and carefully peel it off and stick it to the SSD.
Note where the pad sat on the case, and remove the thick insulating black paint from that part of the copper shield. (I used 1000 grit sandpaper)
Reassemble. (Note: Inspect the battery before closing up the laptop - if any cells are swelling up, you may wish to order a new one)
That's it for the hardware. Enjoy a much quieter laptop as the cooler SSD keeps the fans below full throttle.
Right, now for the software:
The XPS15 has a hardware GPU. For some design reason, it only gets used when the Integrated graphics gets overloaded. I am unsure of the reasoning behind that decision, but it means that processing power is unused for most of the laptop's working life.
Let's make it share some of the load.
Open the NVIDIA Control Panel and navigate to "Manage 3D settings" and the "Program settings" page.
Go through the list of programs and select the programs you use the most, and then tell them to use the NVIDIA processor. Web browsers are a good start. (Note that not all programs have the option of using the GPU.)
Extra details explaining what you have done, and why:
In my case, Chrome browser and image editing software quickly filled up my 16gig of system ram which meant there was a lot of pageswapping to and from the SSD which caused it to overheat and slow everything down. (An upgrade to 32gig of memory made no difference)
By forcing programs to use the GPU, the 4gig of VRAM becomes available which reduces the amount of system memory being used and hopefully the need for as much page swapping.
Removing the sticker from the SSD and the paint from the copper shield has significantly improved the efficiently of the SSD cooling hardware.
I hope this helps others.
It's no wonder that over heating is a problem in DELL laptops.
Look at 3 other things they have clearly designed with no good design:
1. Microphone- it's kept deep into the bottom part of the laptop, good and cheap from a manufacturing point of view, but poor from ergonomic point of view. That portion will never have good voice coming in since it's base of the laptop it's blocked with hands or books or paper or something of that sort. This position also picks up lot of dust from all the tables where my laptop has to be placed.
2. Camera- It's designed into the base of the screen, which is always obstructed by my fingers. All people who take video calls with me complain that they see my hands only like GIANT spiders from Star Wars movie. And my face is always blocked. The camera picks dust from the nearby fans that comes from the heat exhaust inside the HINGE! I mean c'mon DELL.
3. Speakers- needless to say, they have placed right NEXT to the microphone. I mean who does that, you know immediately that any sound coming from the speakers will create a major echo problem since the microphones are next to it. It's like having someone speak loudly into your ears.
So, I am not surprised that this laptop is poorly designed from a internal combustion or heating point of view also.
The machine works well for the most part, but the machine still has random issues that I thought were software related but have only just worked out are actually hardware related.
If your machine gets sluggish and tasks such as "Windows Task Manager" are using up 100% of your CPU, there are a million sites on the net addressing the issue, and each one supplies a different solution, and they are all software solutions.
However, thicker piece of silicone thermal pad for the SSD to prevent the SSD from overheating during sustained disk use or extreme ambient weather which in turn stopped the CPU from being throttled did the job on my machine, as it appears as if the original is just not thick enough.