rasz_pl wrote on 2022-10-18, 19:46:

underclocked MX400 is by definition just an MX

Yes. I know it. But question was still different. 😀
Anyway, I saw some detection program, that detected BIOS marked as "MX400". Maybe through this? Need to test Geforce 2 MX, and more MX400's , it it's a rule. (that MX400 has always marked it as MX400)

Like I said, most brands changed their card designs during switch to MX200/MX400. Original GeForce 2 MX cards were mostly Nvidia reference design with differently colored PCBs and MX400 were mostly brandname design PCBs. You can trace MX and MX400 within one specific brand reasonably well. "Noname" cards from China is a different can of worms, so don't expect any logic.