Have a look at the laptop benchmarks posted with the new phison e18 controller. Granted, that's from phison themselves so take with a pinch of salt, we will need to wait for some independent benchmarks before it can be 100% verified.
The corsair mp600 uses the old e16 controller that is notorious for heat issues when used continuously.
A lot of people don't realise this but the controller is the first point of failure on these drives in terms of what causes the heat (amd subsequent slow down) issues. The old e16 controller got
very hot without heat sinks (there was a comprehensive reddit post that I read last year when I was shopping for a new SSD for my PC build at the time but I can't find it so this will have to do as a reference point for now regarding temperature):
El disipador es fundamental en las unidades SSD NVMe M.2 Gen4, para evitar que se generen problemas térmicos y que caiga el rendimiento.
hardwaresfera.com
To get a better idea of what you are looking at in terms of the hot spot above use this image of the same drive without the heatsink:
As you can see, the hottest part of the drive is very much the controller.
It's well documented that the old e16 controller was rushed in order to enable manufacturers to have "4.0" SSD's available at the time of AMD's X570 chipset launch but the e16 has major shortcomings as a result:
www.anandtech.com
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The e16 is 28nm while the e18 is 12nm.
www.phison.com
Phison are making a big deal about highlighting the fact that this hew controller runs cooler:
Also a recent preview for the new e18 controller gives us some promising information:
The Phison PS5018-E18 is now paired with new firmware and the latest Micron NAND to deliver a client computing SSD that's very capable.
www.storagereview.com