On Sun, 7 Jul 2013 19:00:47 -0300 Christian Robottom Reis kiko@canonical.com wrote:
On Sat, Jul 06, 2013 at 09:39:13AM +0100, Renato Golin wrote:
On 5 July 2013 08:56, Renato Golin renato.golin@linaro.org wrote:
Yesterday I turned one of the boards back to 1.2GHz (3pm), and it died during the night (2am). The 920MHz is still working. The room temperature didn't go over 26C (the thermometer is by the boards).
Status update:
One of the boards failed at 920MHz @ 60% temperature levels. I blamed the power supply and switched to make sure the *other* board would fail as well at 920MHz, which it did. So I retired that power supply and am using a third one, all cheap (all I have here).
I know others have said this, but since you seem to not yet be convinced: the frequency is a red herring. If your PSU can't really keep up with the Panda, all bets are off. We early on in the LAVA lab figured out they only ran reliably on those massive (IIRC, 4A) bricks that Digikey sells.
The alleged PandaBoard compatibility with only a single model of a massive 4A power brick does not sound right. Especially considering that the PandaBoard is supposed to have a superior hardware design quality compared to the competitors:
http://www.pandaboard.org/pbirclogs/index.php?date=2012-10-16#T01:39:33
Earlier Renato Golin mentioned that "These are 5V and on my multimeter I got almost 6V". Looks like some really cheap poorly regulated junk PSU?
My power bricks costed me around 10-15 EUR each (maybe that's overpriced and I could find something several times cheaper from some Chinese vendors?). All of them seem to be working fine, powering various development boards with weeks/months of uptime. And occasionally experiencing long heavy compilation workloads (gcc, libreoffice, llvm, chromium, firefox, ...) without problems. The voltage is very close to 5V, at least when measured without load. I'm getting ~5.2V from the "worst" one and the others deviate much less.
And naturally, any PSU rated for just something like 1A will not work right, that's a common sense. The modern multi-core ARM boards can easily consume a lot more than this under load. But at least 2.5A or 3A should be sufficient if you don't attach many power hungry USB peripherals.