muchomurka said:
Imo no existing SSD has sustained transfer rate as low as 25MB/s; 300MB/s is minimum. Afaik the problem is related to that enclosure/cable/port, not to SSD drive inside.

wiganken: Use Crystal Disk Info to see which SSD is inside the enclosure. Test it by connecting to different port/comp using different cable(s). Connect it to USB2 port & observe the speed.
I have a PNY 1TB that exhibited the same behavior. Thought it was the enclosure. Nope. Changed the cable. No joy. Installed into the laptop. Still, no.

Turns out, it's the drive itself. Lousy buffer.
My Samsung 870 worked just fine in the same enclosure, and internally.
That said, go Samsung or maybe Western Digital.