chip are at ~ 0.85 volt, freq is 08A1 (275 MHz)
~ 140 GH/s per antminer s1
500 watts at thew all for the 3 underclocked ant ! (166 per ant for 140 ghs)
The PSU is a corsair AX1200i
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2FwOhy80a.png&t=665&c=GxohtUfAduldMQ)
420GH/s @ 500W even. That's lower than what I was expecting. I like!
140.8GH/s @ 275mhz means each chip is doing ~2.20GHs/chip. They say 0.85W should be making 2.0GHs/chip, which is a stock of 250mhz. You're OCing 25mhz (10%) above the spec for that voltage. 1.993A per chip x 64 chips, plus a 10% OC means the chips are pulling 119W @ 0.85V. I understand the voltage is slightly higher on the higher chips, so they'll pull more (more W, same A), but I'm averaging.
That PSU is 80PlusPlatinum, which means 92% efficient at 50% load. That means each Ant is pulling ~153W from the PSU. Add ~10W for the controller, and another 5W for the fan (cuz it'll be on low), and you're only looking at 14% inefficiencies from the VRMs.
Our OC ants pull 201GH/s @ 393mhz @ 1.11V. From the wall is 405W, on a 90% PSU = 365W from the PSU. 3.359A per chip (x((393/350)x1.11))=268W (from the chips). Add 10W for the controller, 20W for the fans (I'm guessing here). That means that the VRMs are 20% inefficient on our units.
If we were to go down to 0.75V, and do a 10% OC, you're looking at 112.6GH/s. You're looking at 75W chip draw. Add 14% VRM inefficiencies (although it could be lower than that), and you're looking at 87W draw from the boards. Add 10W for the controller, and 3W for a low power replacement fan, and you're looking at 100W even (from the PSU). Add a 92% PSU, and you're looking at a 109W draw from the wall. This gets you 0.96W/GHs from the wall.