BTW my fridge and the small magnifier ring light both cause enough EMI on the power line here to cause a USB disconnect. Probably the source of much random noise. Half the time when the fridge turns on, cgminer re-inits the KLn device. They're on the same outlet circuit.
How have you connected the outer shield of the usb plug to gnd?
I have often seen at various hubs - that the other shield is also connected via some ferrite beads to gnd.
The outer shield is connected to direct to GND. But you gave me an idea.
I haven't seen it happen again after changing the USB cable to the high quality one from my Canon camera that has a ferrite core near the board connector. I was using the other one because it's short and less clutter on my work bench.
I've wired in the inverters now. The signal has very sharp/fast rise times now and it's easy to see the clock delay is 50nS. I tested it manually in ktest and got all GOOD nonces up to 420 MHz doing repeat work filling the queue . At 430 MHz they came back BAD.
Unfortunately on cgminer the error rate hasn't improved. I haven't run that long yet but I'm seeing 3% - 5% error rates. I believe this is now related to noise on the PLL and instability. It can go quite a long time with no errors, and just when I think Ok, it's down to 1% now, but then a bunch pop up and it's back to 3%.
I'm moving onto final board revisions now. Hope to have a new K16 release later today and k1 tomorrow sometime.
Reading through burnin's and others designs it looks like these chips probably exceed 2A each if you overclock more than a little bit. Have you had any results running say, 8 chips on a 16A regulator (or 16 on 2x 16A regulators) and overclocking/overvolting?
Your buck is at 600khz while avalon's is at 300kHz, both spec'd at 2A/chip, so you should have somewhat better OCability, unless the current is the first limit you hit.
I haven't really tested the O/C range yet. I do brief tests up higher but not any long runs. I'm waiting on a set of spare leads for my Ammeter to cut into a PCIe cable for current measurements.
If there is anything you need that can be sourced in Australia, let me no.. Am flying to BKK on the 21st and can bring it with me...
Thanks. The AUS power cords aren't much use here due the curious angled blades. My sister lives near Brisbane but I haven't been to see her in years. I hope to get down there again before too long.
I'm going to order a couple RFI power line filters from Mouser in my next order. There's two kind I looked at but I'll probably cheap out and order the $4 one instead of $22 one.
10VR3 $22.46
16WGF1 $4.40