Re: ANTMINER S3 Discussion and Support Thread.

Yeah, I know. I tried them with 1 miner per EVGA psu, plus the third on an old Corsair TX750. Still no luck overclocking. I am using a Kill a Watt, and am measuring 1080W at the wall at stock speeds. The max it ever hit was 1150W when trying to overclock.

Quote from: bspurloc on October 17, 2014, 02:01:45 PM

Well how are you going to overclock 3 S3's with 2 power supplies that can't supply enough current to do it??
Each S3 at 250 will draw 400+ watts.
I would connect just 1 or 2 and try to overclock them 243 and 250. if they work then it is what I noted, the power supplies cant supply the amps needed for 3 overclocked

Here are some stats I gathered, just for information sharing. As many are aware, the power from the wall depends on PSU efficiency and used capacity (% of MAX). A single 1000W PSU powering 2x S3+'s will draw more power from the wall than 2 separate same model 1000W PSU's. The higher the PSU capacity , the lower the efficiency.

MHz Setting   Avg Gh/s   Watts      "Efficiency W/Gh"      PSU Model

225            453          400          0.88                  1000W Coolmax, 80 Plus Bronze

225            453          365          0.81                  1050W Cougar GX1050, 80 Plus Gold

225            453          390          0.86                  1200W Coolmax, 80 Plus Gold
237            470          415          0.88                  (Running 2x S3+, Values are per S3+)
250            500          445          0.89

225            453          365          0.81                  1300W Rosewill Lightening, 80 Plus Gold
237            475          385          0.81                  (Running 2x S3+, Values are per S3+)
250            500          405          0.81

thx for sharing, might be a noob question ... if power is 230V compared to 110V would it make a difference ? i think it would.

It doesn't matter. This is regarding Watts, which is constant between 110V and 220V. With 220V, you are using double the Volts at half the Amps. But the Watts is the same. Volts * Amps = Watts

Actually, it has been shown that power supplies using 208-240V rather than 110/120V are 1% more efficient. Aside from 110/220, there are two other important efficiency factors: (1) Ambient Temperature and (2) Percentage of PSU capacity used. With the first, I have seen a 1.3% difference in power consumption between 60*F and 80*F ambient temperatures, mostly due to the fans having to work more or less. With the percentage of PSU capacity used, the sweet spot of most PSU's is 40%. That is where they are most efficient. Efficiency curves are not flat. And Power Supply ratings are based on output, not input, so you can have a 500W bronze PSU pull 600W at the wall. Try actually running one S3 on that Rosewill Lightning and see if you can still hit those same numbers. Then try running three. I bet you will have different results.

Yes, I agree with the PSU capacity impact, which is why I said the same thing. I agree with the temperature impact too, but am not testing that aspect. I've heard disagreements, and back and forth points regarding efficiency of 220V vs. 110V. Some people (not me) say it is more related to the quality of the wiring. I can't speak to the voltage point and don't disagree or agree. I'm working on 1x and 3x S3 numbers on the Rosewill, and will share the results. One problem is that I don't have 2 S3's that will do 250MHz. Most of mine top out at 237 MHz. So I'll be short some metrics. I also have an Antec 1300W Platinum, but it is currently in an S2 and I'm not sure if I want to mess with it.