Damn. I was trying to figure it out thinking we could track by serial number but it seems to be random.
I'll make a list soon to confirm.
Mine were all from the same shop, but I bought them in two separate batches about a month apart. The first batch sold out, so they must have gotten a 2nd batch from the manufacturer or supplier at some point, but both apparently had Hynix memory. I got them really cheap so the ones I got in early december have almost paid for themselves already, so I cannot complain. Equihash has been a goldmine recently, and the cards are putting out 300+ sols/s easily. Samsung or micron would have made them acceptable at ethash as well, but that hasn't really made an impact on my earnings in this particular period I think.