You're going to want to be careful if you're shopping around for a gaming laptop. The GeForce RTX 20 mobile designs have just been launched and it looks as if there are potentially massive performance differences between graphics cards with the same names in different laptops.
Specs for each Nvidia GeForce RTX Mobile GPU can vary massively from laptop to laptop. The GeForce RTX 2080 Mobile, for example, has base clock speeds that can be anywhere from 735 - 1380 MHz, along with boost clocks of 1095 - 1590 MHz. That's a potential 45% difference in clock speed, and likely to be a similar hit to gaming performance. You could theoretically buy an RTX 2080 laptop with a lower boost clock speed than another laptop’s base clock speed. None of these are going to touch the desktop GeForce RTX 2080 either, which comes with a base clock of 1515 MHz on the Founders Edition.
This isn’t really anything new in that thermal designs of laptops have long meant that some will be able to run faster, and hotter, than others, and always slower than desktops, but in this particular instance, the potential performance differential is huge. When you’re spending $1200 on a laptop GPU, you don’t want to be stiffed on performance. The GTX 10-series mobile graphics cards also had lower frequencies but nothing quite like this.
Unfortunately, a heck of a lot of gaming laptops don’t specify the clock speeds of the GPU at all. I’ve been searching around NewEgg and Amazon for Max-Q designs and none of the laptops I’ve looked at have made any mention of graphics card clock speeds. All you can usually find is a distinction between standard and Max-Q.
It’s all a bit shady, to be honest, so we have to recommend you reach out to the individual manufacturers and seek assurances of graphics card clock speeds before you make your purchase. When these RTX Max-Q laptops are costing upwards of $3000, you don’t want to come away with a version that’s half the speed of another.
Aside from the clock speeds, the specs of the RTX 20 Series Mobile chips are pretty similar to their desktop variants. They all feature the same number of CUDA Cores, the same amount of GDDR6 memory, the same memory bus, and the same potential memory bandwidth. However, the mobile chips have the aforementioned lower clock speeds as well as fewer RT cores.
This is definitely something to keep an eye on and, as always, make sure you do your research and read reviews / check out benchmarks before making any large purchases such as a gaming laptop. There are so many things that can wrong with a laptop design in terms of thermals that even the specs can only tell half the story.
And props to Gankutsuou for spotting this!