XPS 15 9510, fails to sleep

A new Windows feature called Modern Standby kicks in when you put the system to sleep mode. In this mode, generally background applications would be running - like Windows updates, wireless activity, etc. So, if it is needed to cool down the system the fans may come on. If you do not like this, you could instead use Hibernate mode. Have you tried the Hibernate mode to see if it works better for you?

I did try hibernate and it is a totally different thing. Also I have 64GB RAM as I said above and hibernating would write the contents of the RAM to the SSD which will degrade the SSD unnecessarily over time.

How can I stop this modern standby and use the regular S3 sleep which doesn't drain my battery and doesn't turn on the fans and doesn't seem to be available for this laptop but was available on all other laptops I used before? 

As mentioned, Modern Standby systems do not sleep.  They go into low power mode so they can behave as your smart phone or they hibernate where no battery drain occurs.

You should be able to shut it completely down but Microsoft believes a system in sleep mode, that has to keep the memory powered, uses more power and has no capabilities while in that mode.

I would really suggest you spend some time getting used to the operation and see if it will offer you some benefits, based on your type of usage, which you may actually like.

Thanks Saltgrass. So far I see no benefit in this kind of sleep.

1. The fans keep working while I am sleeping so there is a constant noise. But if I close the lid the air vents are closed a little by the hinge and the keyboard is covered by the lid so more heat stays inside and the fans ramp up even more and it gets loueder. 

2. If I put this laptop in a bag it will likely overheat of fill up with dust or both. This is not a smartphone and it has RTX 3050 Ti and i7 11-th gen that needs active cooling.

3. There is no way this kind of sleep will use less power than the S3 sleep since the processor is actually working.

I don't even understand what the benefit may be. Maybe Microsoft thinks I like my laptop being rebooted during the night to install updates. I don't know.

And the BIOS shows me an option to disable S3 sleep. This means that it should be enabled if this option is off. And as you can see from my post Windows says that the firmware doesn't support S3. For me this is a BIOS bug that reports incorrectly to Windows that S3 is not available or S3 is crippled by the BIOS intentionally. If so I hope there is a way to downgrade the BIOS so this "feature" disappears.

If the fans are spinning while in low power mode then something is not right with the system. Low power mode is in effect when the display turns off and before hibernation starts. There is nothing that should be working to cause a heat build up..

The processor is not actually working.  It is called a SoC or System on a Chip and the part that wakes up can turn on certain components to take care of chores.

This is a link for Modern Standby.  It is written for Win 8 so you may be able to find a newer version.

What you really need is learn how to create and interpret a Sleep Study log which shows power usage on the system when in low power mode.  It can be very helpful.

Open an admin command prompt and use the command powercfg /sleepstudy to produce the report and keep track where the log is stored.  Once finished, go to the location and copy the .html version to the desktop and open in a browser.

If your fans are coming on in low power mode, it should certainly show what it causing that to happen.  The Microsoft Surface devices are modern standby so I hope Win 11 would not mess that up.

Having said this, I have to acknowledge I do not have your system so I cannot be sure what might be going on.

Modern Standby | Microsoft Docs

I have the exact same issue and I would like the exact same fix. The processor is absolutely working and the system doesn't actually sleep; if I put the laptop in a bag then it becomes burning hot in just 10 minutes.

So far all I get from support is answers like this: "The laptop is working as expected".

What you can do is to check what Saltgrass proposed above. Run powercfg /sleepstudy and try to figure out what is draining your battery. Just click on the red items untill you drill down the core issue.

I managed to turn off the settings for the hardware that was able to get my system awaken, but I still get to a point where the system drains the battery for no apparent reason and then hibernates

And this is where their help ends. They tell me that the OS is choosing the S0 sleep because it is available but completely ignore the line where it says:

Standby (S3)
The system firmware does not support this standby state.

The section of the log you chose to illustrate shows no battery usage, therefore, any info related to it will tell us nothing.

You need to find a line which shows a large battery drain and I am sure a few lines above the one you show would have such an entry.  Look for % of battery drain and check the power info for those lines.

When doing logs like this, the time if very important, so you might even start keeping a record you could compare to the log..  I will attach a log print in a hour or so, in this reply so you can see it.

That's the point. I don't see a logged battery drain, but the red block entry shows:

Drain (dozed to hibernate because the standby battery budget was exceeded)

And then after 2:30 hours hibernation happens for some strange reason.

On the very top of the graph all I can see is a drop of about 5% for this time:

I have my system set to hibernate after two hours.  During that 2 hours, the low power mode uses 3-4% of the battery.  Once it goes into Hibernation, the power drain is supposed to stop, which it seems yours does.  The system does not go into Sleep as you know it.

It also has a batter drain limit which can put it into hibernation, the attachment shows on my system which you can see if you select the space at the end of the power line with the 3 vertical dots.

Saltgrass, what do you think of the behavior of my laptop last night? It seems that the laptop actually goes to sleep, but then it randomly wakes up (which is when it consumes most of the battery).

I looked at some of these events and they are all triggered by the monitor that randomly turns on and off for a variable amount of time:

@alecive87 You are saying whatever the "Monitor" is keeps waking the system up?  You don't have any idea what is happening when the Monitor activates.  

If you can catch it after it wakes up, you might use the powercfg /lastwake command and see if it shows what is waking the system up.  In some cases, it is the network or maybe you have something that monitors movement and turns on when you, or something approaches.

You don't have a cat wandering around, do you?

@SaltgrassI don't have a cat and the laptop was in my bag with the lid closed.

Then I really can't guess what might be waking it up.  I suppose Bluetooth and Wi-Fi are a possibility.   

Did you run the powercfg /lastwake command at any point?  The Display appears to be turning on for about 5 minutes each time, so you may not want to leave it in a bag.

I too recently started to experience this issue. I put the laptop away in its bag only to come back to it an hour later almost on fire as the laptop had not gone to sleep after I closed the lid.

I feel as if Dell doesn't actually care, they just sell some overpriced tech without all of the kinks worked out (I know, new concept for a corporation). 

Off topic for question for you, are your display colors oversatured? Does Dell Premier Color do anything if you switch it from vibrant to srgb?

Hope Dell figures out the actual solutions to these problems because I didn't spend 3k on a laptop to also become a constant programming troubleshooter.