I mean, hardware wise they are not much faster, but cooling is a different story.
The highest spec macbook comes with a 9980HK and starts at 2800 $. A 3900X has approximately twice the performance in multi-threaded workloads and you can easily build an entire quiet workstation with it for less than 1000 $. Half the performance, thrice the price. Great deal.
Yes, there are also "laptops" with a 3900X in them. But even those still have lower performance than a desktop with a 3900X because of thermals.
Specs can never tell the true story, but it's clear that the mobile processor is going to be much slower for anything remotely processor intensive, and probably much more than twice as slow for anything making good use of multithreading.
Having had to go back and forth between a laptop and a desktop for a processor intensive application (AutoCAD) the difference was painful.
* https://www.cpubenchmark.net/compare/Intel-i7-1185G7-vs-Inte...
* https://browser.geekbench.com/v5/cpu/compare/4354735?baselin...
These are short tests too, so would be a best case. In real life, laptop performance is probably significantly worse due to thermal throttling.
Also, laptops generally have CPUs that pull 15 watts. Whereas desktops have CPUs that can pull 95 watts or higher (sometimes up to 150). The difference is astounding.
CAD, for example, barring new geometry work in progress now, is single threaded.
People working on high surface count models want these things:
Big, fat, fast cache
Sustained sequential compute performance
Sustained I/O
GPU that focuses on geometry and precision. This is not generally an issue today, but can be on laptops.
Desktop machines with active cooling are where it is at.
Desktops are great.
Though with water cooling you might also have a lot of pump noise, especially if the radiator is mounted incorrectly.
I heard a story about a DIY PC that did nothing but circulate water through the cpu cooler from a fish tank; the tank was big enough to dissipate heat through evaporation and other means, only occasionally needing a top off.
I actually mounted an automotive transmission cooler to the outside of my PC and made it part of the watercooling loop, because it was inexpensive and large. There are no fans on it, but it still reduces the work the standard pc cooling radiator with the fans on it needs to do.
The most limiting thing is TDP, which in the highest performance laptop processors is still capped at 45W, whereas a maxed out desktop processor can draw 100W or more.
See these tables for i9, for example, compare Coffee-Lake-S (Desktop) with Coffee-Lake-H (Laptop) https://en.wikipedia.org/wiki/List_of_Intel_Core_i9_processo...
Maybe a small desktop. My desktop processor is 180W TDP (Threadripper 1950x), while some others are 250W TDP. You can also get a dual-socket workstation, for 2x CPUs (both pulling 200W each).
Thermals and power are significantly higher on desktops, it ain't even funny. Laptops win in power-efficiency, but absolute performance is always going to be a Desktop.
My Macbook laptop, on the other hand, sounds like a jet everytime I run yarn install.
So yes, desktops have higher thermals. But it handles it so much better than a laptop that it almost becomes irrelevant.
As a result, your 10 year old desktop is probably 50-100% faster than the most expensive Macbook Pro or Thinkpad. It can be quite astonishing swapping to even an old desktop after using a laptop for a long time.
I'm planning to drop in a 5950X upgrade in the workstation in a couple weeks as well. Looking forward to both the huge multi-threaded and IPC gains.
I have mine set to 80% and only set it to 100% if I know I'm going to be away from AC for a while.
Time after time, as someone who's been working on his 10 year old desktop (with a replacement ssd + graphics card when the old one died), I meet devs and analysts using laptops who reason more or less: "well it says i7 and it says x GHz and it says ddr3/4 and it's got a gpu with the same marketing number, so laptops perform the same as desktops cause they have the same hardware in them don't they".
Clearly, what they really mean is "I've never worked with and compared with a desktop". I suppose one of the problems is that SOME of them that have 'used desktops' were actually using neutered VMs in a shared corporate environment that run really poorly and are pretty underspec'd in a shared environment.
But every time, it's actually been the case that not only is the desktop faster and cheaper, but things usually remained faster on an X year old desktop hardware vs more modern laptops for any serious workload.
Edit: and in case it needs to be said, I have both desktops and multiple portable devices in my household because the downside of desktops is clearly portability.
More expensive, less performant, and less serviceable with a suite of proprietary bloatware on top.
I might break the pattern this year though, I got a 3900x last year around launch and moved my 4670k to a home server. I've been pretty impressed with the 3900x while the 4670k has been maxing out all cores in the server for some tasks so was considering buying a second 3900X(T) to replace the 4670k again. But with the rumours about the 5900X, I might end up putting the 5900X in my desktop at the same time as a 3000 series GPU and moving the 3900x to my home server.
Most laptop cooling is awful, but you can certainly find laptops that are well built if you look for it.
Not sure you should weigh bloatware, either. You can trivially install a fresh Windows or Linux and you have to on a custom built PC anyway. If you buy a premade PC, it probably comes with the same crap.
For what it's worth, I switched to a desktop once the core race heated up - now I've got a 12 core 3900X.
I can't believe how much faster it is when it's using all the cores. Night and day. Highly recommended. And 12 cores is barely scratching the surface of the crazy workstations you can build these days.
For tasks 4 threads and less, it would be a bit faster than a current gen Intel laptop chip, but I don't think it would have been worth the portability penalty to me personally if that's all I did with it.
The problem is this base clock speed is given by the CPU manufacturer not the laptop maker. And Intel wouldn't know what kind of laptop it's getting crammed into. So careful definitions don't really help. Desktops are already big clunky things that have to be kept plugged in, I can trust them a lot more to deliver the CPU's promised performance. Whereas laptops are notoriously making compromises because customers tend to be very unrealistic about noise, battery life, etc.
Laptops being power-conscious, they're usually much closer to the point of maximum efficiency on the power curve. In that sense you get better performance per watt. But that's negated by the increased front cost.
At full load, it depends on the heat dissipation; Dell's Precision 7XX0 dissipates heat well enough to keep the CPUs from throttling, but the 5XX0 does not.