Choosing a laptop for professional use is no easy task: lack of competent reviews meet a market full of different models and variants where most important variables are hidden to the final customer.

We have to start with the very basic concept that is behind the laptop performance – efficiency, as the amount energy needed to obtain given performance. Now, to make it as simple as possible, power consumption increase exponentially with frequency: it takes double the power to run at 5ghz than it takes running at 4. This is why since the early 2000s we started adding more cores instead of rising frequencies above the 5ghz mark, as a 2 cores at 4ghz can theoretically perform much better than a single core 5ghz using the same amount of power, wich is the limiting factor expecially in notebooks – in the form of heat that has to be exhausted from the chassis. Modern cpus will set the speed (and produce heat accordingly) for their different cores based on demand, but will always need to keep under a safe temperature (usually 95c), so while a typical notebook will actually run the CPU at a it’s top “boost frequency” while it can – that is because its whole body will actually absorb some of the excess heat “buffering” for a bit – when it gets warm (and that could take just seconds), it will settle to wichever limit the cooling system capabilities impose.
The reason CPUs are designed to run at higher frequency that are not actually possible to cool down is making the system more “responsive” during light use, where the chassis has time to cool down between the short bursts of activity.

The math of the bad, bad i9

One of the most interesting consequence of this behavior is the “i9 paradox” that came to news with the 2018 intel 6 core i9 inside Macbook Pros and Dell XPS 15 – in mobile products, most of the time, the higher frequency parts (given the same core count and cache size) will perform WORST in most cpu-intensive tasks.

I made this rudimental graph using the i9-10980HK vs i7 10870h (both 8 core parts from the same generation), but it applies to every situation where the laptop heat dissipation capability is lower than the maximum CPU power consumption – wich in modern laptops is always. The higher clocked CPU starts at slightly higher frequency, thus heating the whole chassis so much faster that it has to slow down much sooner than the lower-boosting part. The 300mhz frequency advantage of the i9 is actually slowing it down! .

This is also the reason why, when comparing CPUs from the same manufacturer and family, on the mobile space the core count is even more important than on desktops. That is true even in audio production, wich can be much harder to spread through cores, as the advantage in power consumption is just too important to pass by.

Hidden informations – the cooling values and VRM

We do know from CPU specs the maximum frequency it will boost to, but we have no actual information on the real important informations in the graphs above. Its actual power consumption at the given frequency is not disclosed by the manufacturer, and the power limit can be changed by the laptop manufacturer, within some “guidelines” by Intel and AMD.
The sustained performance will depend on the quality of individual laptop model cooling capabilities, as they vary greatly by the size and number of the heatpipes, heatsinks and fans but also with the external temperature, positioning and surface.
Laptop power delivery (VRM) can also overhat / be under specification, like in the 15 and 16 inch Macbook Pros that need to share a small 96w power delivery between the i9 CPU and the AMD GPU.
The only way we have to check these informations is reading good reviews as on notebookcheck , wich will run performance tests in loop to find out the real performance under prolonged workloads.

The new king – Ryzen 4000 / 5000 series

Now comes the debate between AMD and Intel. While on the desktop space there is still an argument to be made for intel in having iGpu and bening monolithic, on the mobile space AMD has 4000 and 5000 series APUs that are monolithic (= no inter-core latencies issues, very bad for audio), have iGpu and on average double the core count at any given price point, are manufactured at 7nm thus consuming less power at the same frequency – and icing on the cacke, they also perform slightly better at the same frequency compared to the old Skylake cores intel is using on the newest 6 and 8 core parts “H” skus. There is clearly no competition on the CPU side – a ryzen 4600h 6 core CPU outperforms much more expansive i7 10750h using around half the power, thus making it possible to have a thin and light powerhouse without thermal or VRM issues. The newest Zen 3 cores on some 5000 series SKUs further reduced latencies, making the 5600, 5800 and 5900 CPUs actually competitive even compared to top-tier desktop 5800x and newest i9 11900k .

RAM and STORAGE

Thinking that different parts inside your machine can “make up” for others is a common mistake; you can’t get more CPU power with a larger drive or adding more RAM (unless it’s about enabling dual channel). Dynamic and Modulation plugins usd in mix and mastering will use neither – it’s all going to be on the CPu (and mostly on a single core). RAM and SSD come heavily into play with samples driven productions – sound libraries like Kontact.

There, you can find yourself limited in the number of voices by ram and SSD access time. Still, you could end up with performance issues if you fit a very fast SSD without looking at its power consumptio, increasing heat and stress on the power delivery, taking away CPU power. This is super important when fitting NVMe inside 2013-2015 macbook pros, wich have huge overheating issues AND are not able to proper power manage non-apple SSDs, resulting in severe performance losses when using supposedly faster drives caused by thermal throttling, similar to the i9 situation on the CPUs.

Less is more / more hidden information: DPC Latency issues.

We have now seen some infos that are quite universal interest – gamers or video, not DAW use only. There is another issue that is very common on notebooks and more a concern for music producers: DPC Latency, wich is the micro-stuttering that can afflict windows when the system is being “held” by a badly written driver, service or program – any “background” task. Drivers for additional GPUs, wifi card, light sensors, touchscreens / touchbars can cause micro stutters that will hurt audio production even on a super high end laptop. This is also the main reason people prefer macs for audio production, as their driver stack & OS are not subject to this issue. The “general rule” to avoid this is going simple – avoid computers with dual GPU (exp nVidia ones) and fancy touch stuff; some review website like notebookcheck will run DPC Latency check in their tests.

Example of a bad notebook – i7 10510u Asus ZenBook Duo UX481

Even though the notebookcheck review might seem positive to the normal user, this 1800 euros notebook is a perfect example of a terrible price/performance device. Starting with the basics, we are getting the i7 10510u CPU with just 4 core, 8 thread for an insane amount of money – and it’s the same old intel 2015, 14nm skylake. We have a very slim chassis and a huge touchscreen: this means that instead of an efficient cooling system, that portion of the system is actually producing even more heat. That’s how, looking in the review, we get a score of arond 530 Cinebench r15 after the first run, while on the same chart an i5 8265u – notice it is supposedly a 2 generation older and lower class cpu – is scoring around 650. And a 700 euros Acer laptop powered by Ryzen 4700u scores 1100 points on the same test.
We can then scroll down to the DPC latency test – the red bar means trouble, probably caused by the touchscreen driver.

A dream machine – the AMD 4800h powered Schenker Via 15 Pro

A review of this incredible machine is on the techtablets youtube channel  : using the Ryzen 4800h and scoring 1900 points on Cinebench R15, it’s on par with a desktop intel i9 and 3 times the double priced zenbook.The european distributor will let you pick individual components at almost-market price, to keep warranty even if you want to max out ram and storage, and the machine has a very capable cooling system while keeping a decent size all thanks to skipping any dedicated GPU. Sadly, we have no idea on the DPC latency figures yet – we will update when whe have some result from friends.