The Lenovo Y540 is a gaming laptop offering some nice specs for a fair price, but just
how hot does it get and does this cause any performance loss? I’ll be taking a detailed
look at thermals and seeing how much we can improve performance with some simple changes.
Let’s start out with the specs I’ve got in my unit, there’s an Intel i7-9750H CPU,
Nvidia GTX 1660 Ti graphics, and 16gb of memory running in dual channel, so expect different
results with different specs. You can find examples of other configurations as well as
updated prices linked in the description.
On the bottom of the laptop we’ve got some plastic mesh towards the back which covers
our air intake, while the rubber feet lift it up to improve airflow, the back one also
seems to prevent rear exhaust being sucked straight back in. On the back we’ve got
two exhausts towards the left and right corners, while both the left and right hand sides have
air exhausts towards the back.
In terms of heatpipes we’ve got one shared between the processor and graphics, along
with a couple of fans, it’s a very similar design to what we saw in the older Y530, let
me know if you want to see a comparison between those.
The Lenovo Vantage software allows us to swap between three modes, quiet, balanced and performance.
I found these modes to adjust the power limit on the CPU between these different levels.
The software also notes that these modes adjust fan speed, however under combined CPU and
GPU load, as you’ll hear later, I observed no difference. Otherwise I did not find these
modes to affect GPU performance at all.
Thermal testing was completed in an ambient room temperature of 21 degrees Celsius, so
expect different results in different environments. At idle it was a little warm, however the
fans were also silent in quiet mode.
The rest of the results are from combined CPU and GPU workloads, and are meant to represent
worst case scenarios as I ran them for extended periods of time.
The gaming results towards the upper half of the graph were tested by playing Watch
Dogs 2, as I find it to use a good combination of processor and graphics. The stress test
results shown on the lower half of the graph are from running the Aida64 CPU stress test
with only the stress CPU option checked, and the Heaven GPU benchmark at max settings at
the same time to fully load the system.
Let’s start with the stress test results, with the quiet profile enabled the temperatures
are a fair bit cooler compared to the rest, however it’s also performing worse, as we’ll
see soon, due to lower power limits. In balanced mode we’re still power limit throttling
due to the limit this mode puts in place, and as the fan was going the same speed as
this test in quiet mode the temperatures rise up. Enabling performance mode boosts the CPU
power limit further which raises temperatures more, and again fan speed was still the same
as this test in quiet mode, and there was still power limit throttling here but also
now some thermal throttling on the CPU.
When we apply the -0.15v undervolt to the CPU, while the temperatures hardly change
performance does go up, as we’ll see in the next graph, however there was still intermittent
thermal throttling on the CPU here. Finally when we add a cooling pad we’re able to
lower temperatures by a fair amount and fully remove the thermal throttling that was taking
place.
The gaming results showed a similar trend, however I did not observe thermal throttling
in this particular game.
These are the average clock speeds for the same tests just shown. We can see with quiet
mode enabled CPU clock speeds are way down due to the lower power limit this mode sets.
With balanced mode these rise up, and then in performance mode they rise a little more,
but not too far before we start hitting thermal throttling limits. By applying the undervolt
we’re able to hit the full 4GHz all core turbo boost speed of the i7-9750H CPU in this
workload, though as mentioned there was still intermittent thermal throttling on the CPU
here, which the cooling pad was able to remove, though we didn’t see it affect performance.
These are the average TDP values reported by hardware info during these same tests.
Basically we can see the CPU power rise up as the different modes affect these power
limits, which while under combined CPU and GPU load seemed to be 25 watts for quiet mode,
45 watts for balanced, and 50 watts for performance. The GPU power limit was not modified at all
with these different modes and was always running with an 80 watt limit.
These are the average CPU clock speeds while under a CPU only workload. With Aida64 and
just the stress CPU option checked I could basically hit the full 4GHz all core turbo
boost speed in balanced mode. This is because of the power limits, in a CPU only stress
test I found both balanced and performance mode would allow the CPU to hit the 60 watt
PL1, just as a reminder under the combined CPU and GPU load we saw the CPU cap at 45
watts in balanced and 50 watts in performance mode. As they’re performing the same at
these levels the temperatures were the same too, though we could lower CPU thermals by
11 degrees with the undervolt applied.
To demonstrate how this translates into performance I’ve got some Cinebench CPU benchmarks here.
We can see that the score increases as we step up the performance profile as expected.
With the performance profile the 2800 score is pretty average compared to other 9750H
laptops I’ve tested so far, while the 3100 result once undervolted is about as good as
I’ve been able to get.
So how do these performance boosts actually translate into games? I’ve tested Far Cry
5 with the built in benchmark at 1080p with ultra settings. At the bottom we’ve got
the results with the quiet profile in use, so while this is performing worse, the results
are honestly not bad, so you’ve got the option of running cooler and quieter if you
want. There wasn’t really a difference between performance and balanced modes in terms of
average FPS, though the higher CPU TDP seemed to boost the 1% low with performance mode.
Finally once we apply the -0.15v undervolt to the CPU and overclock the GPU by 100MHz
on the core and 500MHz on the memory we’re seeing the best result in this test. It’s
worth noting this result with our tweaks is extremely close to the Acer Helios 300, which
has a lot of these improvements by default out of the box, so it will be interesting
when I compare these two in a future video, if you’re new here you’ll definitely want
to get subscribed for that one.
As for the external temperatures where you’ll actually be putting your hands, at idle it
was a bit warmer than the average 30c we usually see. While under combined CPU and GPU stress
test in the balanced mode it’s getting to the low 50s in the center of the keyboard,
fairly warm due to lower fan speeds. When we enable performance mode this doesn’t
seem to change anything, despite this boosting CPU TDP by 5 watts and raising internal temperatures
a bit.
As for the fan noise produced by the laptop, I’ll let you have a listen to some of these
tests.
At idle with the quiet profile it was completely silent, which explains the warmer internals
and keyboard, though realistically not an issue. While gaming or under stress test regardless
of the fan profile in use it was running at the same speed, it didn’t actually change.
I will note though that while under a CPU only workload the fan speed did vary more
between modes, I’m thinking it must have just constantly been above whatever threshold
they’ve got set while under combined CPU and GPU load.
At the time of recording, there’s no option to boost fan speed manually. There were no
options for fan control through the Lenovo Vantage software, outside of what it notes
for the quiet, balanced and performance modes, which as we’ve just seen didn’t help.
In previous models, such as my Y530, you could manually set the fan speed to maximum by pressing
the control shift and one shortcut, however this was not working with the Y540 with latest
BIOS. I don’t know if it used to exist with older BIOS as I haven’t tried it, however
with the Y740 this feature was recently removed, whether on purpose or by mistake I do not
know, so not sure if that’s the same deal with the Y540.
Overall the results aren’t too bad, but could definitely be improved if Lenovo put
back the option to max the fan out, as thermals start to become a limitation. Even with performance
mode while under stress test or gaming the fans were sitting at around 49 decibels, and
while noticeably quieter when compared to most other laptops I’ve tested, it does
start to negatively impact performance. Despite this downside, once we undervolted the CPU
it was possible to gain back most of this lost performance, but this will of course
vary based on ambient room temp, if you’re in a warmer room than me it’s going to be
harder to control, but keep in mind these are worst case scenario tests. I think it
would be great if Lenovo applied default CPU undervolting like we’re starting to see
from other options like the Acer Helios 300 and Razer Blade Pro 17.
While the Y540 gaming laptop is also available in 17 inches, I’m not currently sure how
it utilizes the extra space or if cooling would be any different.
The 230 watt power brick that Lenovo includes with the Y540 was plenty for these specs,
I was seeing some drain during my testing but it would stop at around the 95% mark which
is pretty standard behaviour.
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, as I bought
this machine I can change that in the future, let me know if you’d be interested in seeing
that, however it’s worth noting that when I attempted this with the older Y530 I only
saw minimal improvements and they both seem to share a very similar cooling solution.
Undervolting or using a cooling pad are much easier for most people to do than changing
paste though, and as we’ve seen these tweaks did help improve the performance of the Y540.
Let me know what you thought about the thermals from the Lenovo Y540 gaming laptop down in
the comments, and if you’re new to the channel you’ll definitely want to get subscribed
for the upcoming full review.