Quote from: northcape on August 23, 2013, 12:15:32 PM

Quote from: SebastianJu on August 23, 2013, 10:47:09 AM

Quote from: eraziel on August 23, 2013, 09:46:53 AM

20chips on BBXX = 9gh/s (450 mhz OC)

Till now i didnt find a setting that can do this. And it looks like the temperature the chips have are changing the needed mV to get the best Hashrate, so in theory each Temperature should run its own mV to get the maximum possible hashrate.

Where did you get that from? My 50 chips (20/20/10) run fine at 450 Mhz, 1.330 mV (it seems to overvolt slightly?) and cgminer "d" timing. Rejects and HW errors are reasonable. Temperature is around 47-49°C. Im stuck on the old firmware because of a broken USB connector or my hashrate would be closer to the theoretical 22.5 GH/s.

I have a feeling that these chips would much higher with better cooling but burnins (slightly crude) cooling implementation is hard to beat for price/performance.
Putting fancy copper/heatpipe heatsinks with expensive TIMs on them would probably not make sense from a financial standpoint.

I got that from testing. It seems to make a difference when you run the miner at max 46°C at a certain mV, when its up at 53°C then the hashrate is lower with the same mV. But if you slightly change it you can find the sweet spot again. Its strange but thats my observation.

The newest firmware is indeed good, it gave me a bit speed. I believe 5% more when i remember correctly.

Im not so sure yet with the better cooling. But i will try to change the setting of the fans so that the air is forced through the heatsinks. Maybe it changes something.

Quote from: burnin on August 23, 2013, 12:39:28 PM

Quote from: SebastianJu on August 23, 2013, 10:47:09 AM

You can run it at 450MHz but that doesnt resolve to 9GH/s for me. Till now i didnt find a setting that can do this. And it looks like the temperature the chips have are changing the needed mV to get the best Hashrate, so in theory each Temperature should run its own mV to get the maximum possible hashrate.

have you added the --queue 4 setting to the command line?
That is important to get close to theoretical performance.
My tests showed hashrates very close to 9ghash @ 450mhz for a single board.
Didn't test high OC with a cluster yet though.

I really have to do a MAX-OC test with a single line of chips to find out the real limits.
(maybe even more then 500Mhz)

OC headroom is also chip-dependent, some chips are just better then others.
(One reason why i want to push for individual-per-board OC settings in future firmware revs)

I read the first time of this option. Ill try it. Normally i get the 5 miners slightly above 44GH/s. What does the queue mean to bitburners? Are higher values worth a try?

But i experienced a problem. Today its the second time the miner seems to close down slowly hashratewise. The first time i found after maybe 40minutes. The 5s Hashing was at zero already, now it happened again. The hashing is at 20GH, the watt usage is nearly halved, temperature low and the stats say that the miner is idled often. Im not sure whats the problem but i hope thats not happening over night. The leds were still blinking now. I dont have a clue whats the problem. Does the rpi have to be rebooted some times?

Quote from: eraziel on August 23, 2013, 04:14:52 PM

Quote from: SebastianJu on August 23, 2013, 10:47:09 AM

Quote from: eraziel on August 23, 2013, 09:46:53 AM

20chips on BBXX = 9gh/s (450 mhz OC)

You can run it at 450MHz but that doesnt resolve to 9GH/s for me. Till now i didnt find a setting that can do this. And it looks like the temperature the chips have are changing the needed mV to get the best Hashrate, so in theory each Temperature should run its own mV to get the maximum possible hashrate.

Well, for me it does:

The pools doesnt calculate very correct in my experience. A 1 hour average of cgminer is more trustworthy. Does it say the same? Whats your options?