Any flash storage has two main components: A controller and a set of flash chips, and a third component enters to the picture when connecting these two: number & nature of channels.

Starting from the controller (and channels), beside the obvious PCIe generation, there are some other factors. DRAM support, NAND support (not all NAND is the same!), number of channels, and the speed of these channels. A DRAMless SSD will suffer after its "pseudo-SLC" cache runs out, and the performance of the drive will generally suffer if the number of channels can't absorb the traffic coming from the PCIe side. Here, to have a top notch SSD, you need to have a good/fast controller with DRAM support, and enough channels with enough speed to absorb all traffic requests, so you can get use of the premium NAND chips you bought.

Next, we have the flash layout. Flash chips vary in speed, density and drive. A high density flash chip might be slower, or a flash chip might require higher drive, resulting in higher temperatures in general. In some cases, instead of populating all channels, a manufacturer might decide to populate a few channels and leave the rest unpopulated, creating a big but slower SSD.

Beyond that, there are other considerations like over-provisioning at flash level, "soft SLC cache" size, wear leveling capabilities under sustained load, etc. etc.

For example, an enterprise SSD comes with the "same" TLC chips, but over-provisioned 5:1 or 10:1 (10TB flash for 1TB capacity)

Now, let's see some real-world examples:

- Kingston NV2, NV3: A budget SSD with great capacity and price. DRAMless, no channel number guarantee, and might come in with TLC or QLC chips. Burst speeds are OK, will make 90% of the people happy, but slows down in long transfers and under heavy load. Runs cooking hot in both controller and flash side.

- Kingston KC3000: A higher end drive with part/channel guarantees, handles sustained load better, runs way cooler, ironically.

- Samsung 980/990 Pro: Samsung's higher end drive. Runs cool, sustains speed all over due to DRAM and tons of channels and vertical integration of controller + NAND.

- Samsung T7 Shield: Looks like an bulky 1.8" drive, but it's selling point is it can sustain 1050MB/s writes wihtout even slowing down until it's full. Never gets warm.

So, flash drives comes in all shapes and sizes and with specifications and capabilities all over the place. A WD Blue and WD Black won't perform the same. Same for Sandisk's Plus, Extreme, Extreme Pro series.

This is why OWC was/is the go-to 3rd party SSD provier for Macs for quite some time. They tune their drives similar to Apple's and very similar to what OS expects as behavior. It's not slap some controllers and flash chips on a PCB, change three fields in a firmware and sell.

Flash storage is black magic at this point, and thinking every box is the same is a big mistake.

This comment can be easily 3x longer, but I want to keep it readable.