I have this laptop from like 2012 that I use a lot and I can even say it's my main Linux machine. It's got 8 Gb of RAM and a dedicated GPU so it's not bad but it has an HDD so slow it takes what seems to be 30-60 seconds to launch a web browser. I guess it's 5400 RPM. I want to finally buy an SSD for the machine.
However I noticed that all of the brand new ones that are available in my area are either SATA3 (for SATA) or PCIe 3/4 (for M.2). The laptop obviously supports none of these standards.
Will such an SSD work or do I have to search for a used one with an older standard (like SATA2)? Adapters might be a problem to get because I'm not a customer of marketplaces I can get them from so I'm afraid of getting scammed or just not figuring out the purchase procedure.
That's definitely not true. Spinning rust has all sorts of latencies that slow down read speeds, even in the best case scenario. An SSD has no seek time. You will feel every little difference when the limit is the controller.
This is the correct answer. An SSD was a big upgrade even when SATA2 was the standard, especially against a 5400 rpm HDD.