Maybe some day I'll find a 570/580 card with 2250 ram... but today is not the day. I've noticed the mfg. only put 2000 ram in all the 4gb cards, they save it all for the 8gb cards it seems??
I think none uses 2250 yet...RX570s and 4GB RX580s use 1750, and RX580/8GB use 2000
8GB cards with Hynix go to 2250.
For example this Sapphire Nitro+ Limited Edition RX580-8GB has 2250 Hynix:
https://www.techpowerup.com/vgabios/191263/sapphire-rx580-8192-170320-1They go to...but they're not rated for that frequency, just happen to work at it.
Absolute champ is Micron rated at 1750 that work at 2230
Real 2250 memory would probably oc to 2400-2500 or even higher