What? There’s a lot of laptops that hit their top clocks with no issues. The main problem is that doing so seriously reduces your battery duration and emits significant noise.

Pick anything over the 800$ range that isn’t a macbook and you’re way more likely to hit clocks than not.

The problem isn't hitting the top clocks, but sustaining them. Only the biggest "desktop replacement" class laptops tend to be able to sustain 120W+ CPU dissipation.

Note that workstation-class (H) laptop CPUs also make compromises on performance - the Ryzen 9 4900H is 8C16T but only has 4MB L2$, 8MB L3$, and a max TDP of 54W. A desktop Ryzen 9 3950X by comparison is 16C32T and has 8MB L2$, 64MB L3$, and a 105W default TDP (and will go much higher with even basic PBO if your cooling allows). The differences on the Intel side are even starker.

As an aside you have an interesting notation, using $ to substitute for cache, using that symbol never once crossed my mind hah

Hmm, I suppose it's fallen a bit out of favor recently, I don't see it quite as much as I used to, but it's pretty much standard terminology in the semi industry showing up in everything from academic papers to data sheets (commonly you'll see that as D$ and I$ - data and instruction cache).

Perhaps why I've not seen it before is likely due to localization - I'm in the UK and of course the Pound has it's own symbol, thus the connection of $ -> Cash -> Cache may not be so readily made.

> Only the biggest "desktop replacement" class laptops tend to be able to sustain 120W+ CPU dissipation.

Yes. And as a bonus, I can use my Alienware 17 R4 as a throwing weapon. Or for workout. And the power brick is a perfect cup warmer.

But I like it, nonetheless.

Hey! I never thought of using the brick to keep my coffee warm. It is even the right size. Excellent! Thanks....

Ignoring the discussion around TDP figures, I’m well aware of the power limits, but that was (IHMO) not the point of OP.

It’s obvious that it’s impossible at the moment to get 3950X performance in a laptop format, but you can get laptops able to keep temps reasonable with 35-50W, and that’s what a lot of laptop SoCs target as total power.

Those SoCs hit (and sustain) their top clocks, whatever those are for that specific SKU.

What I understood from OP is a common complaint for macbooks, that fail consistently to sustain their specified to clocks, because Apple deliberately under specifies their cooling solutions for better ergonomics (and design reasons).

> Those SoCs hit (and sustain) their top clocks, whatever those are for that specific SKU.

This is actually completely wrong. Almost no laptops sustain their top (boost) clock on heavy workloads. Most usually only sustain max performance for minutes (or seconds!) before throttling. Here's an example chart that shows how various premium Athena/Evo U laptops perform: https://www.notebookcheck.net/Asus-Zenbook-S-UX393JA-Laptop-...

On the workstation side, people complain about Macbooks, but recent MBPs actually throttle their Intel H processors less than a comparable XPS 15 for example: https://www.notebookcheck.net/Apple-MacBook-Pro-15-2019-in-r...

If you are interested in how modern Intel laptop chips throttle and what base and boost clocks mean, you want to do a search for PL1, PL2, and Tau. For AMD chips, you will want to look up STAPM, Fast and Slow PPT.

Note that while a i7-10875H's top "boost" clock is 5.1GHz, the sustained "base" clock is only 2.3GHz. This is so low to be meaningless as a top speed. In practice, unless your laptop's cooling is absolutely terrible, you'll probably end up mostly running in the 3-3.5GHz range under full load. In comparison, on a properly cooled desktop system, a same-gen i9-10900K desktop system should be able to maintain a sustained (all-the-time) clock of about 5GHz (very close to its 5.3GHz boost). AMD chips scale a little bit better due to 7nm having better power efficiency and how PPT works, but the same ratio roughly applies.

I’ve actually worked with Ryzen SoCs myself (I do board design).

This is the problem with all the marketing BS. When I talked about “top clocks”, I wasn’t referring about “boost” clocks. I’m talking of the clocks that the SoC is designed for (that won’t appear on the box), i.e. a lot of laptops are not leaving “performance gaps” due to bad cooling, those SoCs are designed for that level of performance and attaching a fat copper heatsink won’t do much difference.

I had a lot of trouble with a client that complained that our board was not properly designed because the performance they were seeing was not “as advertised”. In the end we had to ship the whole thing to AMD, and have them test the system with a thermal sink. Everything was as expected.

If anyone is interested in this kind of stuff, your explanation is really good, so I won’t add anything because I’d probably do a terrible job :)

I agree that there's a lot of misunderstanding on clocks - I've been on the other end - evaluation and validation of embedded boards, including V1000 Ryzen SoCs, but I think I'd disagree somewhat with the characterization of clocks as purely "marketing BS."

Back in the day, most CPUs had had a fixed clock, but these days modern Intel and AMD chips simply don't - they all clock opportunistically, which depends on powers, thermals, but also workload (try running an AVX-512 loads for example). How do you characterize "clock" in this context? Base (minimum) and Boost (hard limit, now split to Max Turbo <2C and All Boost MC) seem to be reasonably sensible numbers.

Now we can argue semantics all day, but to bring it back around if you're just going to say "top clocks" is what the SoC was designed for at a specific workload/power envelope (In AMD's PB, that'd be PPT, TDC, and EDC) then every laptops will "hit their top clocks with no issues," but I'd say that argument (statement?) is a bit circular/pointless. ;P

Well, you can get a 3950x on a laptop, capped at 95w TDP. XMG, Cyberpower and Schenker sell those (manufactured by Tongfang)

My 3950x got to 315W socket power with OC. It wasn't stable, as it was just testing.

Can you keep them in prime 95?

Yes, but only with ear protection and while the battery can keep up. When the battery is out of power, the computer shuts off. Need to buy a better powersupply than the one it came with...