You mean the boards from C1?

Once I have tried connecting my Antminer S3+ to hashing board from C1 (Batch 2) and it appears that
- C1 hashing boards have a default voltage which causes them to have efficiency of ~0.8w/GH
- C1 controller undervolts boards at startup (efficiency is about ~0.73w/GH)
- S3+ board does not seem to undervolt the board from C1

I need to be sure that the hashing board doesn't turn out to have efficiency of ~0.8w/GH.

I'm interested in buying a single Antminer S3 (plus or not) hashing board. Location: Eastern Europe.