Throughout my laptop reviews you may have noticed that I'm not particularly a fan of
single channel memory, as typically you'll get more performance out of dual channel,
but by how much?
In this video I've tested 16 different games at all setting levels, as well as 9 CPU benchmarks
to show you the differences in performance between single channel and dual channel memory
in a laptop.
Generally when people talk about memory they focus on total size, such as 8gb vs 16gb,
or even speeds like 2400mhz vs 2666mhz.
While these are important, they aren’t what we’re talking about here.
So just a quick explanation of what single and dual channel memory actually means.
The simplest way of understanding it, is that single channel memory is where you run one
physical stick of memory, while dual channel is where you have two physical sticks of memory
installed, there’s more to it than that but that’s the simplest way to understand
it in a laptop, as pretty much all motherboards these days should have support for dual channel.
As a common misconception it’s also worth noting that single or dual channel memory
has nothing to do with the memory sticks themselves, so you don’t buy single or dual channel
memory, it depends on how many channels the platform supports.
In a dual channel configuration the memory bandwidth is doubled, which is what we’re
testing here.
To test this out I've used the Metabox P950EP laptop which I recently reviewed, when arranging
for the laptop to be sent over I asked if I could get two 8gb sticks and one 16gb stick
of DDR4 memory to do this testing and they were happy to help out.
The laptop has an Intel i7-8750H CPU along with Nvidia 1060 6GB graphics, and the memory
was running at 2,400MHz speeds in both single and dual configurations, so same speeds and
same total size of memory, all we’re changing is single to dual channel.
All tests were completed with the exact same Windows updates, Nvidia drivers, and game
updates applied, literally the only thing changing between my tests was swapping out
the memory sticks.
We'll start with the gaming results then work our way into the CPU application tests after.
Starting out with Fortnite we’re getting pretty nice results with both configurations,
however there’s a noticeable difference when stepping up to dual channel, with an
8% boost on average at max settings and even larger at lower settings.
Overwatch was tested playing with the bots, and at max settings there’s just a 3% boost
on the averages, but a 16% boost in 1% lows, and again much larger increases as we drop
down in settings.
PUBG was tested using the replay feature, so the exact same replay was tested in both
memory configurations.
At Ultra settings we’re seeing a 14% improvement to the averages, and a 34% improvement to
the 1% lows.
CS:GO was tested using the ulletical benchmark, and with maximum settings there was just a
4% performance improvement, but this increases up to 13% in the averages at minimum settings.
Rainbow Six Siege was tested with the built in benchmark, and at max settings there was
just under a 3% improvement but over a 17% improvement in average frame rates with low
settings.
Battlefield 1 was tested in the first campaign mission and at ultra settings there was a
17% performance improvement in the average frame rates, but more importantly a 47% improvement
in 1% lows, and once more this increases as we lower the settings.
Far Cry 5 was tested with the built in benchmark, and while there was only a 3% improvement
to the averages at ultra settings there’s a much larger 25% to the 1% lows, which again
rises at the lower levels.
Assassin’s Creed Origins was also tested with the built in benchmark, but we’re seeing
a much larger performance increase in this game, over 31% better averages at max settings
DOOM was tested using Vulkan, and in this game we’re only seeing a very small difference
in performance, which rises a little more at the lowest level.
In The Witcher 3 there’s basically no difference in terms of the averages at max settings,
but the 1% lows are seeing more improvements, and this seems to apply to the other settings
too.
Ashes of the Singularity was tested as more of a CPU intensive game, and in this one there
was just a 4% improvement to the averages at max settings, but this rose up to 43% at
low settings.
Ghost Recon saw similar results, the same 1% lows at max settings with almost no difference
in the averages, but this rises to around 20% at low settings.
Dota2 was tested using a fairly intensive replay, and at ultra settings we’re getting
just under a 30% improvement to the average frame rates.
Rise of the Tomb Raider was tested using the built in benchmark, and at ultra settings
there was just a 3% boost to the averages, which increases to 16% at the lowest settings.
Shadow of War was also tested with the built in benchmark, and at max settings the results
were basically the same, and slowly grew apart as we move down in setting levels where there
was a 15% improvement with dual channel at minimum.
Watchdogs 2 is a fairly resource intensive game, and at max settings dual channel memory
was giving us close to a 10% improvement on the averages, and up to 43% of an increase
to the averages at low settings.
In general we saw larger performance increases at the lower setting levels, which makes sense
as the CPU is used more at lower setting levels while the graphics are actually better utilized
at the higher setting levels.
Additionally, the dual channel configuration seems to have made nice improvements to the
1% lows, which received larger improvements than the average frame rates.
Now onto the benchmarking tools, I’ve tested Heaven, Valley, and Superposition from Unigine,
as well as Firestrike, Timespy, and VRMark from 3DMark, just pause the video if you want
a detailed look at these results, but for the most part in these tests there wasn’t
very much difference with single or dual channel configurations.
While I expected better results running in dual channel going into this testing, I didn't
expect anywhere near this much of a performance boost in the games.
I tried to test as many games as I had available at all setting levels to try and give the
best coverage, and all tests are the average result of multiple runs, so I was consistently
seeing these differences.
Now let's check out some more CPU specific workloads.
Starting out with Cinebench there was basically no difference at all, realistically these
results are within margin of error ranges, both single and dual channel results are the
averages of 5 tests.
In Adobe Premiere I’ve rendered my review video on the ASUS Zephyrus GX501 gaming laptop,
which goes for around 10 minutes at 1080p, using the h264 high bitrate preset.
No GPUs were in use for the test, these results are CPU tests only, and the export completed
about 13% faster with the dual channel configuration.
A similar result was noted in Handbrake.
I’ve encoded a 4K video file to 1080p, and a separate 1080p video file to 720p using
the HQ presets.
There 1080p export completed 8% faster with the dual channel configuration, while the
4K export was just 2% quicker.
The 7-Zip benchmark was used to test compression and decompression speeds, and the additional
memory bandwidth seems to help out a lot with compression, with almost a 40% boost to the
compression speeds, but almost no difference in decompression.
The VeraCrypt benchmark was used to test the AES encryption and decryption speeds, and
in the dual channel configuration we’re seeing a 35% improvement to both of these
tasks.
In the PassMark 9 benchmark the single core results were basically the same, with a much
larger difference in the multicore test, which scored about 17% better with dual channel
memory.
Geekbench 4 showed similar results, not too much of a difference at single core, then
just under a 17% improvement in the multi core test.
The Corona benchmark renders a scene using the CPU, and was just under 5% quicker in
dual channel configuration.
The V-Ray benchmark was also run, and in this particular workload there was almost no real
difference between single and dual channel configurations.
In these CPU specific tests overall dual channel configurations were performing better, although
it varied quite a lot as it greatly depends on the specific task and how much it depends
on the memory bandwidth performance.
Should you upgrade to dual channel memory in your laptop?
If you've got a spare memory slot free and want to boost performance, then it can definitely
help out in some workloads, especially games.
Even though the price of memory is currently quite high, in most modern laptops you aren't
able to upgrade the CPU or graphics, typically you’ll just have the option of changing
the memory or drives.
Yeah, some laptops do allow you to swap out the CPU or GPU, but it’s far less common.
If you're buying a new laptop and have the option of selecting single channel memory
or paying a bit more for dual channel, then I think it's definitely worth considering
paying the extra for a dual channel configuration, though of course it depends on exactly how
much.
If your laptop has integrated memory that's soldered to the motherboard, like the Dell
XPS 15 2-in-1 I recently reviewed for example, then unfortunately you're out of luck and
are not able to easily upgrade.
The best way to know for sure would be to check the manual for your specific model of
laptop on the vendor's website, or even just simply open up the laptop and see how many
slots you have and what memory sticks are currently in place.
You can definitely use software like HWInfo to check, but occasionally I've found some
laptops to report incorrect information that does not match up to the physically available
memory slots when opening it up, so probably worth actually checking and confirming before
buying some shiny new RAM.
There's also the issue of mismatching memory.
Typically if you're already running in single channel it would make sense to simply buy
another stick of the same size to move to dual channel, rather than buying two new sticks
and wasting your existing stick of memory.
While mismatching memory doesn't seem to be as big of an issue these days as it was in
the past, generally where possible it seems to be recommend to use the same sticks of
memory in dual channel for best compatibility, I don’t personally have any experience running
mismatched memory in laptops so I can’t speak from experience on this topic.
I've been asked in previous videos if additional memory will increase heat, technically I suppose
it would, as there's an additional component that requires power to run, but realistically
I doubt it will make any negative difference to performance and offset the gains to be
had, especially as thermal throttling in the CPU/GPU is generally what you worry about
with heat and those components aren’t directly connected to the heatpipes anyway so it really
shouldn’t matter.
So there you have it, in general a dual channel memory configuration will give you decent
improvements in gaming, but it of course depends on the specific game and settings used.
As we saw here bigger gains can be had at the lower setting levels, presumably because
the CPU is actually doing more work as discussed.
As for other applications, it will depend on whether or not the specific workload will
benefit from increased memory bandwidth, but in general where possible I’d definitely
suggest running in dual channel where possible for best performance.
So do you guys run in single or dual channel, if you’ve just got single what’s stopping
you from upgrading?
Let me know your thoughts down in the comments, and leave a like if you found all the benchmarks
useful, and consider sharing the video with someone that’s interested in this topic,
I’d greatly appreciate it as this video took a long time to make due to all the benchmarks.
Thanks for watching, and don’t forget to subscribe for future tech videos like this
one.