The M15 is Alienware’s thinnest gaming laptop with some pretty powerful specs, but powerful
hardware in a small space generally results in heat and throttling. I’m going to perform
thermal testing with the M15 and find out what sort of performance and temperatures
we’re looking at, as well as what we can do to cool it down and improve it.
In my configuration here I’ve got the Intel i7-8750H CPU with Nvidia GTX 1070 Max-Q graphics,
so expect different results with different hardware.
Thermal testing was completed with an ambient room temperature of 25 degrees Celsius. It’s
worth noting that there are heatpipes shared between processor and graphics, so a change
in one component may affect the other.
Starting at the bottom of the graph, at idle the temperatures are a little warm, although
the fan was completely silent as you’ll soon hear. The gaming test was done with Watch
Dogs 2, as I find that to use a good amount of combined CPU and GPU resources, and we
didn’t quite hit sustained CPU throttling while playing this one, as we did with the
stress tests, shown by the CPU sitting at 99 degrees Celsius.
The stress tests were done by running Aida64 and the Heaven benchmark at the same time
in order to attempt to fully utilize both the processor and graphics. There was no change
in CPU temperature even with the CPU undervolted by -0.12v, but we’ll see in the next graph
how this helped with performance. With my cooling pad in use I was able to drop the
GPU temperature by around 10 degrees Celsius, and with the cooling pad plus CPU undervolt
right at the top we went from constant thermal throttling to intermittent thermal throttling,
and for the first time hit power limit throttling instead.
I haven’t tested with the fans manually maxed out through the Alienware Command Center
software as there was no need, during these tests it was hot enough that it was always
running with 100% fan speed.
These are the average clock speeds for the same tests just shown. Down the bottom in
the gaming tests we can see a slight GPU clock speed bump with a 200MHz overclock applied,
but a larger 300MHz boost to CPU clock speed with the -0.12v CPU undervolt applied. With
the stress tests running the CPU clock speed rises steadily as we make improvements. With
the cooling pad in use we’re getting better results on the CPU compared to undervolting
only as thermal throttling is the enemy here, then finally at the top with the combination
of cooling pad and CPU undervolt we’re not too far behind the full 3.9GHz all core turbo
speed of the 8750H in this worst case scenario, but still running quite hot though.
These are the clock speeds I got while just running CPU only stress tests without any
GPU load. Even with a CPU only stress test there was thermal throttling taking place
which prevented the full 3.9GHz all core turbo speed of the i7-8750H, though we were able
to achieve full performance with the -0.12v undervolt applied to the CPU. These are the
temperatures for the same test, so thermal throttling at stock at 99 and then this lowered
by 7 degrees Celsius while undervolted while giving us more performance.
To demonstrate how this translates into performance I’ve got some Cinebench CPU benchmarks here,
with the older 7th gen i7-7700HQ just down the bottom for comparison, check the card
in the top right if you want to see a detailed comparison between these two CPUs. There’s
no change with or without the CPU undervolt in single core speeds as that’s not enough
to cause any throttling, but we can see a 110 point boost in multicore due to the thermal
throttling being removed while undervolted.
Here are the GPU only clock speeds while under a graphical only stress test, and with a 200MHz
core overclock applied we’re seeing a 127MHz improvement, and we’ll see how this affects
game performance later. With the overclock applied the temperatures rise by a couple
of degrees, and I’ll note that this is a fair bit higher than most other graphics only
testing I’ve done with other laptops, though no thermal throttling in this test.
So how does this performance boost actually translate into games? I’ve tested with the
exact same Windows, Nvidia and game updates installed, the only changes were the ones
listed here.
Far Cry 5 was tested using the built in benchmark, the average frame rates at ultra settings
were 7.3% better compared to stock speeds, and there was a 7% improvement to 1% low,
so we are able to get a decent performance boost from overclocking the graphics and undervolting
the CPU, though results will of course vary between game.
As for the external temperatures where you’ll actually be putting your hands, at idle it
was in the high 30s in the center of the keyboard, most others are closer to the 30 mark. While
gaming the center of the keyboard is in the mid 50s, fairly hot for this area, though
closer to 40 degrees for the WASD area, then similar results with the stress tests running,
again up to the mid 50s towards the back.
As for the fan noise produced by the laptop, I’ll let you have a listen to some of these
tests.
At idle it was completely silent, I used the silent profile which is why the temperatures
were in the 50s, but this does show we can run it quieter. While gaming and under stress
test it was actually a little quieter than most other gaming laptops I’ve tested, despite
the fans running at 100%, at least according to Alienware’s Control Center software.
While the gaming performance seems pretty good, it was a bit sad that there was CPU
throttling present even in CPU only workloads without adding on GPU load at stock configuration.
The product page for the M15 makes it sound like they’ve got a good cooling solution,
but unless I’ve just got a bad unit that does not really appear to be the case. In
Dave2D’s review he talks about being impressed by the cooling, showing 80 degrees Celsius
on the CPU and GPU and noting that there is no throttling even under stress test, which
does appear to be the case in the time spy stress test he’s using.
From what I can tell he usually only tests with a single pass of Firestrike, whereas
I test each measured point on my graph for 30 minutes, meaning my thermal testing takes
at least 4 hours just to complete my first graph. In my opinion a single pass of Firestrike
isn’t enough to show temperatures you’d get from sustained gameplay over time, and
my test with the Time Spy stress test also didn’t represent this either, and is in
my opinion misleading of how the M15 performs. Sure, most of my tests are worst case, most
people won’t be maxing out both the CPU and graphics for long periods of time, but
the fact is the results are worse when compared to most other gaming laptops I’ve tested
that have the same specs in a similar form factor with the same tests. I don’t seem
to have a unit with poor contact between the dies and heatsinks either, I get extremely
similar results to Dave when using the Time Spy stress test, I just don’t personally
think that’s a realistic demonstration of temperatures that we see while playing real
games, or at least not with the games I use, it will of course depend on the game. In any
case I’m not the only one to report high temperatures with the M15, but as shown we
were able to make some improvements.
These differences in performance shown aren’t hard and fast rules, there are different factors
which will vary results, primarily the temperature of the room you’re running in, application
of thermal paste, and even the specific hardware which comes down to the silicon lottery. You
may not be able to undervolt or overclock your hardware the same as me, it depends on
the chip and its specific power requirements, so don’t just blindly copy my settings and
do some testing to find out where your stable point is for best results.
It may be possible to further improve temperatures by swapping the thermal paste, however as
this is a review unit that I have to send back I’m not able to change the paste, otherwise
the next reviewer will unknowingly report different results due to what I’ve done.
Undervolting and using a cooling pad to improve air flow is much easier for most people to
do anyway, and as we've seen it did improve performance in the M15. I’ll be interested
to compare these results with the new RTX versions of the M15 in future, so get subscribed
for those comparisons.
Let me know how much of a performance boost you’ve found by undervolting your hardware
and what you thought of the improvements here, and course don’t forget to subscribe for
the full review of the Alienware M15 gaming laptop, as well as future tech videos like
this one.