Quote from: mjgraham on August 26, 2013, 06:34:03 PM

Quote from: Bluestreak66 on August 26, 2013, 07:16:43 AM

Friedcat said at higher speed there is a chance that the micro is not capturing the nonce which would explain why speeds may not be as high as they should. I'm hoping he may post some more info on here.

I never tried 17mhz but I have a 18mhz installed and it will not run @ below 1.4v.

Well a 17 does not exist most likely I am using a signal generator, however I am going to have a nice chart to post, so far I am at 20 Mhz however were getting up there on voltage and heat density is making me worry. I can tell you so far were looking at 1.50V @ 3.992A for 20 MHz. I started at 12 MHz and made a chart with the common available oscillators and worked with each one until no HW errors in 5~10 min, long term hard to say. Should be done testing by tomorrow, maybe the fan wont quit in the middle of the night and a fire break out

Although so far at this test there are 4% HW errors. Is the maximum that everyone believes 1.8v? I think it is going to take a peltier to go to much farther then that adds another level of something to mess up.

As for the 1.4V at 18 MHz that is right on with what I have at that point.

Awesome, Good to see results are matching up. Are you getting the correct hash rates as you increase speed? As I said in one of my first post, I think heat dissipation will be the limiting factor. Also we need to come up with a better solution than a lab power supply to power these with. There are some cheap dc/dc converters on ebay I'm curious if they would provide a clean enough output to power the chip or several in parallel. I had a 70w peltier on mine running 16 and then 18mhz, It worked great until condensate formed the it locked up and the thing froze over. Shocked