My PSU is Enermax EPM1350EWT and had no problem to power 2 Antminer S3+'s.
What should I check to make SP20 running stable?
More questions.
Where can I get Users Guide? I found quick start guide only.
What is default SSH login/password?
ssh is root/root
webui is admin/admin
Make sure you get something which can cover the specs: Power Consumption: 1100 watts at the wall with a Gold rated, 90% efficiency PSU suggested
Try to power it from 220V (6.5 A max) for better efficiency. If using 110V you might need 2 PSUs, as one will draw close to 14A from the wall and the efficiency is not that great.
The Enermax EPM1350EWT is spec'd as follows: +3.3V@24A, +5V@24A, +12V1@20A, +12V2@20A, +12V3@30A, +12V4@30A, +12V5@30A, +12V6@30A, [email protected], +5VSB@3A
Make sure you don't use the PCI-E 20A outlets, use the bold ones.
Make sure the connectors there have 16AWG wires. Do not fall for thinner ones. Those get hot. Last resort, see Roadstress' post below.
One S3+ is about 355 Watt at the wall. Two of them is double the SP20 has almost double the hash of your earlier setup with a slightly better efficiency when fine tuned. Expect almost double of the power requirements (i.e. the equivalent of about 3.5 x S3+ units). GUIDE? Ask here , you will get answers.