Batch 4 and 5 are sold out.
lasted just a couple of days.
anyway, my B4 order finally 'turned green'.
Interestingly, S7 batch 6 went from 162 to 145 chips (144? as 145 cannot be divided by 3-weird)
This contains an error, they put 45 chips per hasboard, total 135 chips, not 145:
batch 1, 3 and 5: 4860 / 162 = 30 (total hashpower / number of chips = hashpower per chip)
batch 6: 4050 / 30 = 135 (total hashpower / hashpower per chip = number of chips)
So, they went from 54 chips per hashboard to 45 chips per hashboard.
Now it is easilly to found a PSU, but it is still too high...
Well the maths works for 135 Chips . The only snag is that with 45 chips / Board the only maths that works is 15 Nodes of 3 Chips, one less node than with 144 Chips and that would mean that the Core Voltage with a 12V Supply would be even higher. 12V / 15 = 0.8V and that is way too high. That is if the BM1385 Data Sheet is to be believed?
Rich
And whats the deal? Its the same price, or even higher than the "lesser batches" for less hashrate. What is this, the "Lays marketing trick" where they just sell less chips per bag but use the same price to milk more money off customers?
They must have implemented something on the board to regulate down the Voltage to the 0.6X range, why go through all this trouble? I don't get it and its bothering me, mostly because i was thinking on picking up one soon, i guess.
This is not what i had in mind when the rumours of the "S7 mini" started going around...
Well it's all a bit of a mess.
The original "Leak" with 3.5ish TH which would have been possible with a 2 Board S7 made a lot of sense.
Now Bitmain tell us it's got 145 chips which does not work. So we guess 144 Chips which can work, the core voltage increases, which is plausible given the problems they have been fixing by lowering the frequency.
Another bit of maths suggests it might be 135 Chips, again the maths work but core voltage is now up to 0.8V which according to the data sheet particularly given that the PSU spec now goes to 13V is definitely too high.
The pictures all still just show the original S7 Hash boards with 54 Chips so that does not help. So I guess we are just going to have to wait, unless someone from Bitmain want's to put us out of our misery?
Rich
