The ASUS GX701 is the 17 inch model of the Zephyrus S, and like other Zephyrus models
it’s got a custom design to improve cooling, so let’s test it out and find out just how
hot it gets. I’ll be taking a detailed look at thermals, overclocking, and seeing how
much we can improve performance by undervolting and boosting fan speed.
I’ve got the GX701GX model of the 17 inch Zephyrus S here, which means there’s an
Intel i7-8750H CPU and 90 watt Nvidia RTX 2080 Max-Q graphics. It’s also available
with 2070 or 2060 graphics too, so expect different results with those configurations.
The ASUS Zephyrus laptops have a unique cooling solution, when you open the lid the base of
the laptop rises up to allow air to exhaust. The keyboard and touchpad are found towards
the front of the laptop, as the whole second half of the chassis are the intake fans. There
are also heatpipes shared between the processor and graphics, so a change in temperature of
one will affect the other.
Before we look at the temperatures I need to mention that the The ASUS Armoury Crate
software provides three different modes, silent, balanced and turbo. Silent basically lowers
the TDP of the CPU to save power and reduce fan noise, balanced is essentially stock settings,
while turbo mode overclocks the GPU core by 100MHz and GPU memory by 124MHz. Additionally,
while under a combined CPU and GPU workload the CPU TDP is limited to 40 watts in balanced
mode, and boosted to 45 watts with turbo mode, and turbo mode also increases the fan speed
to help with cooling, as raising the TDP will generally increase heat along with performance.
Thermal testing was done in an ambient room temperature of 24 degrees Celsius, so expect
different results in different environments. I’ve tested idle down the bottom with the
silent profile, and the temperatures were fairly cool. Gaming was tested by playing
Watch Dogs 2, as I find it to use a good combination of processor and graphics. The stress test
results are from running the Aida64 CPU stress test and Heaven benchmark at the same time
to fully load the system. We can see that every time turbo mode is enabled the temperatures
drop down, and this is because of the increased fan speed associated with this mode. The CPU
temperatures are a little on the warmer side, however I did not encounter thermal throttling,
just power limit throttling. A -0.07v undervolt was applied to the CPU where listed by UV,
like other ASUS Zephyrus laptops I’ve tested I couldn’t go much lower without problems.
These are the average clock speeds for the same tests just shown. We can see the GPU
clock speeds rise any time turbo mode is enabled as the previously mentioned overclock gets
applied. The CPU clock speeds also rise as well, as the CPU TDP gets boosted, while undervolting
helps further. These results are actually pretty good, especially from such a thin machine,
while gaming with both turbo mode enabled and the CPU undervolting I could hit the full
3.9GHz all core turbo speed of the i7-8750H CPU, and then only just below this at the
top of the graph with the worst case scenario stress test running.
These are the clock speeds I got while just running CPU only stress tests without any
GPU load. With the Aida64 stress test running it was possible to hit the 3.9GHz all core
turbo speed of the i7 either with turbo mode, or with balanced mode combined with a CPU
undervolt. Likewise here are the temperatures from the same tests just shown, where the
undervolt in the balanced and turbo profiles lowers the temperatures by a few degrees.
To demonstrate how this translates into performance I’ve got some Cinebench CPU benchmarks here.
There’s no difference to the single core results, as this isn’t enough load to cause
any throttling. The results otherwise closely match the CPU only clock speeds just shown
before.
Here are the GPU only clock speeds while under a graphical only stress test with the balanced
and turbo modes, as well as the improvements seen by applying a manual 150MHz overclock
to the GPU core with MSI Afterburner, although it wasn’t much above what the turbo profile
provided. Here are the temperatures from these same tests, balanced mode saw hotter temperatures
despite the performance being lower as the fans don’t spin up as fast compared to turbo
mode.
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 at 1080p. At ultra settings there was no change
to average frame rate, but an improvement to 1% low, while the other setting levels
saw the opposite. Either way the boost was fairly minimal, which I think is because the
graphics were already overclocked thanks to turbo mode, so I suspect most of the improvement
here is probably from our slight CPU undervolt, which I think is good as you can easily get
excellent performance out of the box.
As for the external temperatures where you’ll actually be putting your hands, at idle with
the silent profile enabled the keyboard was around 30 degrees celsius and a bit warmer
up the back. While gaming the keyboard was still fairly cool, in the mid 30s, while the
back gets much hotter in comparison as that’s where the heat generating components are.
Same story with the stress tests running, it does get up to the high 50s up the back
and is quite hot to the touch, but you shouldn’t be putting your hands back there anyway so
that’s fine. While gaming on battery power the keyboard does warm up a bit, as the battery
that’s being discharged is right underneath.
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 quiet, although the fan was still audible. While gaming in balanced mode
it’s a little quieter than most other laptops I’ve tested at stock, then same results
with the stress test going in balanced mode. Finally with turbo mode it does get a bit
louder, though still around average compared with many others.
Overall I think the Zephyrus design is doing a good job here, I wasn’t seeing thermal
throttling even under combined CPU and GPU workloads despite the fans being quieter than
many other laptops I’ve tested. The CPU can still get fairly warm under these worst
case loads, but as we saw using the higher fan speed in turbo mode and applying an undervolt
kept it going smoothly. The unique cooling design does however mean that you won’t
be able to run the laptop with the lid closed while docked though, so worth keeping in mind
if you planned on doing that. The 230 watt power brick also seemed to be adequate, I
didn’t see performance loss or the battery drain under heavy loads while plugged into
the power.
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. For example my
i7 only got a -0.07v undervolt before becoming unstable, I’ve had other laptops that would
easily take -0.15v no problem.
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 raising the fan speed is much easier for most people to do, and as
we've seen it did improve performance in the ASUS GX701. I didn’t bother trying to use
my cooling pad here, as the base of the laptop has no air intakes like a normal one, so it
wouldn’t help as much.
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 ASUS GX701 gaming laptop.