Last night I wired up a harness to adapt the S4 to an IBM 2880W PSU with 10ga wiring and ring terminals. Here are some pictures (Cables are a tangled mess, need to be cleaned up and wire tied in place):
The PSU's are rated to handle 2x S4's. Because I don't currently have a 2nd S4 to test with, I have 2x Asicminer Tubes running at 270 Mhz each connected as well, which should put at least as much load as a 2nd S4. So far the PSU has no problem keeping up, nor should it. I have tested the PSU's to around 2950W for weeks at a time without problem. I will try to fit a 2nd S4 to run both off the IBM 2880W and show pictures.
Breakout boards for the IBM 2880W can be found in J4bberwock's thread for Europe/Asia/Worldwide:
https://bitcointalk.org/index.php?topic=893159.0Or in my thread for Canada/USA:
https://bitcointalk.org/index.php?topic=966135.0For cables I used 24" PCIe to PCIe cables cut in half and stripped, crimped butt connector and shrink-wrapped 10 ga wiring for both power and ground as well as a ring terminal. If anyone wants to make up a similar harness, the measurements for the 10ga wire length are as follows (in addition to the 12" of PCIe cable with bare lead connected to the board)
12V+
21"
27"
22.25"
27.25"
12V-
21"
27.25"
23.25"
28"
Additional PCIe cable to power BBB board is approx. 36" to the breakout board.
Cables to power 2nd S4 (if stacked underneath) can be same length, but connected to the closer side of breakout board.
