TL; DR: No you can’t. Thanks to Dell and Microsoft.

And why would anyone run Linux on an Alienware gaming laptop anyway? Well, I do.

I tried to enable deep sleep for my Alienware laptop running Arch Linux. While I couldn’t be bothered to do this on some other laptops because even in the default suspend to idle/S2 mode the power consumption was not too bad. But with an Alienware M18R2, basically a desktop in a laptop’s disguise, S2 drains the battery really hard.

In case one asks why S3 state saves much more energy than S2? In a nut shell, in S2 state the whole computer is still powered on including the CPU running at the most idle mode possible, hence the name suspend to idle. On the other hand in S3 mode everything is powered off except the memory.

Thus I would give S3 a try. Ideally, this should be simple on Linux:

# run as root
cat /sys/power/mem_sleep 
[s2idle] deep

# switch to deep/s3
echo 'deep' > /sys/power/mem_sleep
# this is what's needed to turn on s3 on an old XPS13 running Fedora Linux

But on my Alienware

# as root
cat /sys/power/mem_sleep
[s2idle]
# WTF!?

I did a bit of research, this nice article explains it well:

I reached to Dell support and they told me that they don’t support S3 simply because Windows 10 may have BSOD after wake. They don’t care about other OS and they don’t give customers a choice.

I guess it’s Ok that one solves a problem by hiding it from everyone, even if someone calls itself a tech company 🙂