Re: Overheating Pandas

Folks, I had my final round of tests and I can say that there is no final conclusion on why they fail, but they do failed under every scenario I could try them on. I've tested 3 identical boards (Panda-ES RevB2) with 5 different power supplies. Even at 920MHz, with decent power supplies (high-qua

Re: Overheating Pandas

On 8 July 2013 14:48, Siarhei Siamashka wrote: > 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

Re: Overheating Pandas

On Sun, 7 Jul 2013 19:00:47 -0300 Christian Robottom Reis wrote: > On Sat, Jul 06, 2013 at 09:39:13AM +0100, Renato Golin wrote: > > On 5 July 2013 08:56, Renato Golin wrote: > > > > > Yesterday I turned one of the boards back to 1.2GHz (3pm), and it died > > > during the night (2am). The 920MH

Re: Overheating Pandas

On Sat, Jul 06, 2013 at 09:39:13AM +0100, Renato Golin wrote: > On 5 July 2013 08:56, Renato Golin 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 thermome

Re: Overheating Pandas

On 5 July 2013 08:56, Renato Golin 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 92

Re: Overheating Pandas

On 4 July 2013 12:27, Renato Golin wrote: > On 3 July 2013 18:33, Richard Earnshaw wrote: > >> keep lowering the clock limit (.../cpufreq/scaling_max_freq) until you >> get stability. If you don't, then it isn't a heating problem. >> > > It might be a bit too soon, but I just got a few 7h build

Re: Overheating Pandas

On 4 July 2013 19:15, Mans Rullgard wrote: > Chips intended for compute clusters will no doubt be possible to cool > sufficiently to run at full speed all the time. Designing chips for > different > markets involves different sets of tradeoffs, and you're seeing the result > of that. > Yes, thi

Re: Overheating Pandas

On 4 July 2013 18:10, Renato Golin wrote: > On 4 July 2013 17:13, Siarhei Siamashka wrote: >> >> By the way, power consumption is not constant and heavily depends on >> what the CPU is actually doing. And 100% CPU load in one application >> does not mean that it would consume the same amount of p

Re: Overheating Pandas

On 4 July 2013 17:34, Siarhei Siamashka wrote: > For getting reproducible benchmark results, you just need to ensure > that thermal throttling never kicks in. If the kernel is compiled > with cpufreq stats enabled, you can compare these stats before/after > your benchmark to ensure that it spent

Re: Overheating Pandas

On 4 July 2013 17:13, Siarhei Siamashka wrote: > By the way, power consumption is not constant and heavily depends on > what the CPU is actually doing. And 100% CPU load in one application > does not mean that it would consume the same amount of power as 100% > CPU load in another application.

Re: Overheating Pandas

On Wed, 3 Jul 2013 16:48:51 +0100 Renato Golin wrote: > But more to the point, I don't want to be scaled down when hot, I want it > never to get hot in the first place, so I can run at full 1.2GHz, 24 / 7. > If the scheduler reduces the frequency to decrease the temperature, I'll be > testing mor

Re: Overheating Pandas

On Wed, 3 Jul 2013 15:59:47 +0100 Mans Rullgard wrote: > On 3 July 2013 14:13, Renato Golin wrote: > > Hi Folks, > > > > I'm running two buildbots here at home and am getting consistent failures > > from the Pandas because of overheating. I've set up a monitor that will tell > > me the current C

Re: [Linaro-validation] Overheating Pandas

On 4 July 2013 12:58, James Tunnicliffe wrote: > Faster clocks also drink more power - now you are using slower clocks > those boards will be stressing the PSU less. That is true. Though, if memory serves me well, I think I was using one decent power supply and one cheap in the lab, and both Pan

Re: [Linaro-validation] Overheating Pandas

On 4 July 2013 12:27, Renato Golin wrote: > On 3 July 2013 18:33, Richard Earnshaw wrote: >> >> keep lowering the clock limit (.../cpufreq/scaling_max_freq) until you get >> stability. If you don't, then it isn't a heating problem. > > > It might be a bit too soon, but I just got a few 7h builds

Re: Overheating Pandas

On 3 July 2013 18:33, Richard Earnshaw wrote: > keep lowering the clock limit (.../cpufreq/scaling_max_freq) until you get > stability. If you don't, then it isn't a heating problem. > It might be a bit too soon, but I just got a few 7h builds out of the boards at 920MHz without a single glitch

Re: [Linaro-validation] Overheating Pandas

On 4 July 2013 11:29, Mans Rullgard wrote: > That is not how electricity works. > I may not have myself clear, I suppose... We can digress at Connect about electricity. cheers, --renato ___ linaro-toolchain mailing list linaro-toolchain@lists.linaro.o

Re: [Linaro-validation] Overheating Pandas

On 4 July 2013 10:08, Renato Golin wrote: > On 4 July 2013 10:00, Milosz Wasilewski > wrote: >> >> What is the output current of this PSU? I tried running pandaboard >> with 2.5A PSU and it didn't even start. 3A seems to be the minimum. > > These are 5V and on my multimeter I got almost 6V, but i

Re: [Linaro-validation] Overheating Pandas

On 4 July 2013 10:01, Matt Hart wrote: > I've just had a quick glance at the rack in LAVA Lab with the pandas in > it, and it seems like we are using the 5V 4A brick style power supplies, > not the cheap ones. > I know, but somewhere in the lab there's a box full of the cheap ones, and these are

Re: [Linaro-validation] Overheating Pandas

On 4 July 2013 10:00, Milosz Wasilewski wrote: > What is the output current of this PSU? I tried running pandaboard > with 2.5A PSU and it didn't even start. 3A seems to be the minimum. > These are 5V and on my multimeter I got almost 6V, but it's not just the voltage, but the constant supply of

Re: [Linaro-validation] Overheating Pandas

I've just had a quick glance at the rack in LAVA Lab with the pandas in it, and it seems like we are using the 5V 4A brick style power supplies, not the cheap ones. Matt On 4 July 2013 10:00, Milosz Wasilewski wrote: > On 4 July 2013 09:44, Renato Golin wrote: > > On 3 July 2013 23:01, Will Ne

Re: [Linaro-validation] Overheating Pandas

On 4 July 2013 09:44, Renato Golin wrote: > On 3 July 2013 23:01, Will Newton wrote: >> >> It may also be worth examining your power supplies and see if they are >> providing enough current to run the chip this hot reliably. A bench >> supply could eliminate this possibility conclusively. > > > T

Re: Overheating Pandas

On 3 July 2013 23:01, Will Newton wrote: > It may also be worth examining your power supplies and see if they are > providing enough current to run the chip this hot reliably. A bench > supply could eliminate this possibility conclusively. > They're cheap... *very* cheap... They're not the ones

Re: Overheating Pandas

On 3 July 2013 14:13, Renato Golin wrote: > Hi Folks, > > I'm running two buildbots here at home and am getting consistent failures > from the Pandas because of overheating. I've set up a monitor that will tell > me the current CPU temperature and the allowed maximum, and when the bot > passes 90%

Re: Overheating Pandas

On 3 July 2013 18:33, Richard Earnshaw wrote: > On 03/07/13 17:41, Renato Golin wrote: >> >> On 3 July 2013 17:22, Mans Rullgard > > wrote: >> >> I repeat, the 4460 will run at 1.2GHz indefinitely without thermal >> management. >> >> >> My mistake, I said 1

Re: Overheating Pandas

On 3 July 2013 18:33, Richard Earnshaw wrote: > Chips expected to dissipate large amounts of power normally have a metal > pad on the package so that a heat sink with thermal grease will make a good > thermal contact. > This is a really good point. The heat-sink do get really hot, but it's not t

Re: Overheating Pandas

On 3 July 2013 18:08, Mans Rullgard wrote: > 4430 max frequency is 1.0GHz unless I'm mistaken. Either way, try > reducing your clock to 1.0GHz and see what happens. > Yes, I meant 4430 and 4460 at their natural high frequencies. $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_freq

Re: Overheating Pandas

On 03/07/13 17:41, Renato Golin wrote: On 3 July 2013 17:22, Mans Rullgard mailto:mans.rullg...@linaro.org>> wrote: I repeat, the 4460 will run at 1.2GHz indefinitely without thermal management. My mistake, I said 1.3GHz when it was actually 1.2GHz. So, at 1.2GHz, it freezes every few

Re: Overheating Pandas

On 3 July 2013 17:41, Renato Golin wrote: > On 3 July 2013 17:22, Mans Rullgard wrote: >> >> I repeat, the 4460 will run at 1.2GHz indefinitely without thermal >> management. > > > My mistake, I said 1.3GHz when it was actually 1.2GHz. So, at 1.2GHz, it > freezes every few hours on full load on b

Re: [Linaro-validation] Overheating Pandas

On 3 July 2013 17:41, Renato Golin wrote: > On 3 July 2013 17:22, Mans Rullgard wrote: >> >> I repeat, the 4460 will run at 1.2GHz indefinitely without thermal >> management. > > > My mistake, I said 1.3GHz when it was actually 1.2GHz. So, at 1.2GHz, it > freezes every few hours on full load on b

Re: Overheating Pandas

On 3 July 2013 17:22, Mans Rullgard wrote: > I repeat, the 4460 will run at 1.2GHz indefinitely without thermal > management. > My mistake, I said 1.3GHz when it was actually 1.2GHz. So, at 1.2GHz, it freezes every few hours on full load on both 4430 and 4460. linaro@linaro-panda-01:~$ cat /sys

Re: Overheating Pandas

On 3 July 2013 16:48, Renato Golin wrote: > On 3 July 2013 15:59, Mans Rullgard wrote: >> >> An OMAP4460 will run at 1.2GHz indefinitely without overheating in >> reasonable ambient temperature. >> >> If you don't have thermal management in the kernel you're running, you >> need to clamp the cloc

Re: Overheating Pandas

On 3 July 2013 15:59, Mans Rullgard wrote: > Modern silicon processes are much more power-efficient than those of the > 90s. > For example, an old ~500MHz Alpha machine I have readily consumes 90W even > when idle. A quad-core Intel i7 typically has a TDP of 130W at full load. > That's orders of

Re: [Linaro-validation] Overheating Pandas

On 3 July 2013 15:42, James Tunnicliffe wrote: > I believe that in the LAVA lab there are a few pandas with USB keys > that are used for builds to try and overcome some reliability > problems. I'm using USB drives for that reason. Is running at 100% of the thermal limit really an issue? Isn't

Re: Overheating Pandas

On 3 July 2013 14:13, Renato Golin wrote: > Hi Folks, > > I'm running two buildbots here at home and am getting consistent failures > from the Pandas because of overheating. I've set up a monitor that will tell > me the current CPU temperature and the allowed maximum, and when the bot > passes 90%

Re: [Linaro-validation] Overheating Pandas

I believe that in the LAVA lab there are a few pandas with USB keys that are used for builds to try and overcome some reliability problems. Don't know if it was a temperature problem or something else. With any luck someone who knows more about that issue can speak up and share what they found. You

Overheating Pandas

Hi Folks, I'm running two buildbots here at home and am getting consistent failures from the Pandas because of overheating. I've set up a monitor that will tell me the current CPU temperature and the allowed maximum, and when the bot passes 90%, it shuts itself off. The problem is that I'm runnin