I’ve currently got the Aorus X5 v8 gaming laptop for testing and I’ve seen a lot of
people talking about thermal issues with it. I’ve noticed that it can run quite warm
under load, even with the fans running at full speed power limit throttling and thermal
throttling was happening, so let’s take a closer look and find out if we can improve
things with some undervolting.
This laptop has Intel's new 8th generation Coffee Lake i7-8850H CPU, which has 6 cores
with 12 threads and supports overclocking. By default it’s clocked at 2.6GHz, but the
single core turbo boost speed is 4.3GHz, while the all core boost speed is 4.0GHz. Out of
the box my unit was actually overclocked to 4.3GHz on all 6 cores, so we’re going to
need good cooling to actually get good performance with this.
By undervolting the CPU we're essentially telling the CPU to use less power to perform
the same tasks, and less power results in less heat. It’s quite simple to do using
Intel's Extreme Tuning Utility, also known as XTU. Put simply, you slowly decrease the
core voltage level, run a stress test to confirm stability, then once confirmed to be stable
drop the voltage some more and repeat until you've got a stable system. If you take it
too far you'll blue screen in Windows if the CPU isn't getting enough power. With my Aorus
X5 I was able to undervolt the 8850H by -0.150v, and this is what I used in my testing.
Testing was done with an ambient room temperature of 18 degrees celsius, it’s approaching
winter here so expect warmer temperatures in a warmer environment.
At idle both the CPU and GPU sat below 40 degrees celsius, otherwise it was running
fairly warm. The gaming result in green was done playing PUBG at high settings with the
fans on default speeds. The yellow bar just above this was also from playing PUBG, but
with the CPU undervolted and CPU overclocked on all cores to 4.4GHz and GPU overclocked
by 120MHz. Undervolting the CPU alone was enough to drop the temperatures a little even
while overclocked, and we’ll see how this affected clock speeds in the next graph.
Full Load was tested with Aida64 and the Heaven benchmark running at the same time, and with
the fans at both default speed or maxed out the temperature was the same, as the fans
were very close to full speed already, but you’ll hear this for yourself shortly. Finally
the purple bar is the same stress test but with undervolting and overclocking applied,
and we can see this gave us just a slightly better GPU temperature. At 90 degrees the
CPU was thermal throttling, it didn’t go above this and the clock speeds suffer as
a result.
Here are the average clock speeds while testing so you can see any throttling. While gaming
with PUBG at stock settings no throttling was observed, we can see all CPU cores averaged
around 4GHz which is the all core turbo speed of the 8850H. While overclocked all cores
ran just under 4.3GHz, despite having them set to 4.4GHz in this test, and this appeared
to be due to power limit throttling, this was improved a bit with the undervolt though.
In the stress tests there was some thermal throttling taking place, even with the fans
on maximum, despite this undervolting the CPU did still improve things quite a bit,
as shown in red the CPU cores were around 500MHz faster as a result of the CPU undervolt
and only just barely throttling.
If the GPU load was removed completely the CPU temperature would drop quite a bit into
the low 80s. These are the clock speeds I got while just running CPU only stress tests.
Without the undervolt the CPU was power limit throttling rather than thermal throttling,
thermal throttling was only happening with a combined CPU and GPU workload. Undervolting
the CPU not only dropped the temperatures as shown earlier, but also reduced the power
limit throttling, resulting in the higher clock speeds shown here, so it’s helping
out in more than one way.
I did attempt GPU undervolting, but I wasn’t able to see any noticeable difference. I tried
starting with small changes, then larger using MSI Afterburner but it didn’t seem to be
helping.
As for the external temperatures where you’ll actually be putting your hands, at idle the
body of the laptop is sitting in the low 30s, so it’s quite cool. While gaming this increases
to about 44 degrees and is a little warm to the touch in the center, but it’s not too
bad, and I saw a very similar result while running the stress tests, however the wrist
rests and right side of the keyboard stayed fairly cool in comparison, and I didn’t
really notice any differences with the undervolt or overclocking applied.
As for the fan noise produced by the laptop, I’ll let you have a listen to some of these
tests.
At idle the fan was still audible but it was fairly quiet. While running the stress test
and while gaming the total system volumes don’t change much, and they were only just
behind the full fan speed.
Going to full fan speed didn’t really change the temperatures as it was basically already
close to maxing out anyway and it was fairly loud.
Great, so how does this performance boost actually translate to games and practical
applications? I’ve used Cinebench to just quickly show the differences in CPU performance,
again as mentioned earlier the undervolt removed power limit throttling, the CPU wasn’t actually
thermal throttling with a CPU only workload. As undervolting makes the CPU use less power
it removed the power limit throttling that was taking place, thereby improving performance.
I’ve just tested a small handful of games with and without the -0.150v CPU undervolt
applied with 4.3GHz on all 6 CPU cores.
In Rise of the Tomb Raider with the built in benchmark we’re seeing approximately
a 4.5% improvement while undervolting compared against running at default, as expected the
lower settings show a better result.
PUBG shows a similar result, almost no difference at higher setting levels with a small boost
at the lower settings.
Dota2 is behaving the same way, the results are almost the same here in all but the lowest
setting levels.
Ghost Recon with the built in benchmark is once again showing us the same results, except
with better 1% lows this time.
For a synthetic benchmark I’ve used the Heaven benchmark from Unigine, and again fairly
similar results.
As shown the improvement by undervolting the CPU does seem to translate to slightly better
gaming performance, nothing spectacular, though it depends on the game.
As expected we tend to see a larger boost in performance at the lower setting levels,
which makes sense as with lower graphical settings you're more likely to be CPU limited
as there's less work for the GPU to actually do, whereas at the higher setting levels the
GPU is able to stretch its legs, so the gap closes a bit more.
Realistically with the high end hardware in the Aorus X5 you’ll probably be gaming at
higher setting levels, so even without undervolting it’s performing pretty well, but this may
depend on the game. Although we saw some clock speed differences under a full stress test,
the fact is most games don’t fully max out both the CPU and GPU to cause this behaviour.
It does run loud and warm, but as we’ve seen it still runs great in games, you could
always put on some headphones if the fan noise is too much for you.
These differences in performance shown aren’t hard and fast rules, temperatures will vary
between laptops depending on factors such as how well paste was applied and even the
silicon lottery. This basically means each CPU and GPU probably has different limits
with regards to the amount of voltage required to run, so just using my numbers with your
own laptop probably isn’t a good idea, the results will vary, but if you’re experiencing
thermal throttling then attempting undervolting could give you a performance improvement as
we’ve seen here.
Replacing the thermal paste is another option to try and improve this issue, but unfortunately
this isn’t something I can do with a review unit for a number of reasons. Generally, a
company won't really want you to tamper with the laptop as it needs to work in the same
way for the next person to receive it. If I go ahead and replace the stock thermal paste
I can't really put the old paste back, so the next reviewer would experience something
different from what you'd actually see with the product and report incorrect results.
Undervolting on the other hand isn't physically intrusive, and as we've seen it did improve
the performance in this particular unit, granted the temperatures didn’t really change much
we were able to get some more performance out of it. Using a cooling pad could possibly
help too, but I’m hoping to investigate that more in a future video.
I’d be interested in hearing your experiences with undervolting and how much of an improvement
you’ve seen down in the comments, and leave a like if you found the information useful.
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one.