I'm looking at buying a nvme SSD today, and currently need to choose between the WD Blue and the WD Black. Which should I choose? (Black is about $20 more)

WD Blue, if I remember correctly, is DRAM-less and uses HMB to "borrow" from system memory to cache read/writes. I'd pay the difference to get a Black, but if you're buying it for regular use you might not notice any difference between the two, especially if you have plenty of system RAM.

In general, WD's color coding translates to:

Blue = general use
Black = higher performance, but still intended for home/personal use
Green = low cost / lower performance / non-critical personal storage
Red = tuned for NAS drive caching scenarios
Gold = tuned for enterprise high-end use

The DRAM-less WD SSD is the Green line. Both WD Blue and WD Black have onboard DRAM for caching read/write operations.

Grab the WD Blue and save some cash. The WD Black line of SSDs borrows the brand name from the HDD lineup, where the Black drives are high-performing devices, while the Blue drivers are for general purpose use. For the SSDs, the differences from Black SSDs and Blue SSDs are mostly marketing BS targeting the "gamer" market these days.

Additionally, I would recommend checking the Crucial SSDs, as they tend to be cheaper than other brands while being on par with Samsung drivers in terms of performance and longevity. I still have an older Crucial M4 128GB SSD running since 2012 at 96% integrity, which was my primary boot drive for years on my main computer (later replaced with a larger Samsung SSD). I also currently run a 1TB Crucial MX500 SSD for my games, and I have no complaints.

Times change. The SATA version of WD Blue does indeed have a DRAM cache, but OP specifically mentioned "NVMe".

If you're doing heavy usage and your motherboard doesn't have an NVME heatsync/spreader, get the WD Black with the heatsync - it's good for sustained faster read-write. Also, it's better if you have a heat issue in your build.

If the $20 makes a difference to your build and affordability of other parts, or you won't have a need for long, sustained read-write, I'd go for the blue.

In my build, I've got a B450 Tomahawk motherboard, so no heat spreader and went for the WD Black with heatsync.

**If you're using a 7400RPM HDD at the moment, either will seem blisteringly fast.**

I ended up going with the Black. It will take a while to arrive, but I don't exactly need it anytime soon (I won't have a use before I get the rest of my build ready, and I haven't ordered anything else).

What's your build plan look like? I'm curious to know what you're building, personally. I know it will be a Linux machine, right?

Yes. My thoughts are:
* CPU: AMD Ryzen 3400g (was hoping for a sale, but it's actually more expensive than normal now)
* Will use integrated graphics instead of a GPU. (Note that, if I do change my plan and get a discrete GPU, it will not be an Nvidia card, and I am not willing to spend more on it than I spend on the CPU.)
* RAM: 16GB or 32GB (I'm leaning toward the latter right now).
* Motherboard not decided.
* Also haven't chosen a case.
* OS: Probably debian bullseye, at least to start. (bullseye is currently testing; it will freeze next year, and then release, probably later in the year.)

Also, the SSD I got doesn't have a heat sink; is that important? (In particular, do such devices generate enough heat for that to be a concern? The most intensive thing I'd likely be doing would be running buildroot, which compiles an entire system from source code.)

I'm assuming Asrock 450m Steel Legend + Ryzen 5 3400G + NVME+SSD...?

How big was the NVMW you chose btw? 512 or 1024?

I went with a terabyte.

Not currently planning on a second disk, though I might take the 2tb one from my current desktop. (Note that it's spinning rust, but it is SATA rather than IDE.)

Also, why do you assume the Asrock Steel Legend? What's good about that motherboard?

No, no need to add more cooling options unless you use a lot of magnetic HDDs and/or a heavy GPU. Just make sure you have one way airflow in the case, like in in the front and out back/back top and you're set.

https://www.techpowerup.com/forums/attachments/upload_2016-1-18_13-56-17-png.71169/

Didn't hear anything else so I just guessed it and asked, nothing more (ref the other thread).

Agree with Sanscript - without a discrete GPU, heat is less likely to be a problem. NVME SSDs throttle if they get too hot, so all you would see with high temps would be a slowdown in speed until they cool down. However, this is still going to be faster than a SATA drive would be.

If you're worried though, you can always buy a cheap aftermarket heatsink (or get a motherboard with an integrated heatsink for the NVME drive).

Depends on where the M.2 slot is located on the motherboard. On my Asus Z170-A, it's on the other side (not near the GPU).

That's a nice design decision. So many stick the NVME drive under the GPU - although it's not as batshit as the early design decision when they put the M2 slot physically underneath the board.