Quote from: JCviggen on June 26, 2014, 07:32:22 AM

Quote from: bcp19 on June 25, 2014, 10:26:54 AM

I just read Josh's posts and see he stated we are using grade D... I thought I heard B... my fault.

Even so, any wafer those "D" came from will not have grade "A" if A means going that much faster than what these are doing.

Besides, the logic of this exercise this escapes me somewhat. BFL must have thousands of these chips, surely using TWO grade A chips isn't going to make a lick of difference in terms of supply?
Which school of business did the decision makers study to use the worst hardware they have on the shelf and then use that to demonstrate the functionality of an upcoming product? If they have A grade chips they would be able to clock them way higher without actually drawing more power through the PCB. And without a hilarious error rate. Having a board hashing at slightly more proper speed and with a low error rate might stem the flow of refund requests a little, at least. Seems worth using a tiny fraction of a percentage of A chips.

But, according to you, they don't want to waste any of the "good" chips on a demo. They must really be short on A grade chips. Do they even have two?
Any info from BFL is difficult to take seriously these days, but if it makes as little sense as this I'm confident to call it nothing but pure undiluted BS.

There are none so blind as those who will not see....

The PCBs currently in hand (there were several hundred of this revision made) cannot support speeds above ~550GH with "A" chips due to heat constraints (copper layer chiefest among them). Choices... throw away all these boards or build them with lower grade chips and use them for the cloud hashing Josh posted about (and I see at least one forum member is currently using). While I have no idea what the "D" chips can run at, they do run fast enough for this purpose. Why waste grade A chips on an inferior board? Why push the board beyond it's limits just cause the chip can handle it? The increase in power to run the chips faster causes a greater current draw and therefore a higher W/GH rating. Why waste the extra electricity for a few extra GH?