Does this mean the 400GH/s kit can made to easily go up to 640GH/s? What's required to do this? Changing some resistors and crystals?
They will do about 614 GH/s. Please see:
At 0.8 V and clock of 54, these chips get 2.4 GH/s each. 16 H boards x 16 chips per H board x 2.4 GH/s per chip = 614.4 GH/s.
These are not the same boards.
No, but Dave has stated in this thread that the H board's voltage reg maxes out at 0.8 V, which is the apparent stock voltage. So, all one needs to do is adjust the clock.
edit:
Apparently H board v reg maxes out at 30 A and stock voltage is 0.65 V, so you will need to modify the resistor to get voltage up beyond that
This post seems to specify that achieving this performance on an H board will be difficult without extensive modification to replace both the resistor and the v reg
cscape, a few of us are wondering how much the h-card can be overclocked to. Have you tested that? We know that it is limited to the regulator.
30A reg maxout is on the board. 40A max at core limit.
There is no reg subtitute with higer limits (as I know, I already tried to find). To maximaze the chips hashrate we might need board with less chips.
dave and cscape qutoes;
For 0.65V you need exactly 1K resistor for R01F.
For 0.70V you need 1.5K.
With 1K resistor I get 1.26Amps @ 12.0 V, so 15Watts for an h-board.
[edit] Remember, with 16 chips, soldering that higher value resistor will quickly max out the amps that the regulator can handle.
The 2.7GH/sec result I got with a single ASIC test board required 2.5A, and 0.835V. If you were to attempt that on the whole board, the total current of 40A would exceed the capabilities of the regulator.
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btw great work cscape, awesome!
Picture is kind of look but can not touch
Come on investors, grab this oportunity!
