Am 18.08.2017 um 12:18 schrieb Michael Mrozek EvilDragon@openpandora.org:
Am Thu, 17 Aug 2017 22:39:33 -0700 hat Tony Lindgren tony@atomide.com geschrieben:
Thanks, that's interesting!
One more info from the distributor: As Dual Die chips basically have twice the load, the might need a different combination of resistors and capacitors than Single-Rank chip.
Well, this means signal load i.e. resistors and capacities inside the chip (Si on SiO2 forms resistors and inductors and capacitors as well).
So we can't change those.
What can be changed is the drive strength on the OMAP side. This is more or less equivalent to changing driver resistance.
In other words: higher driver strength sends stronger signals and this charges/discharges capacitors formed by the Si chips in the DDR3 Multi Chip package faster. Faster charge/discharge gives better signals (usually) and more room for timing misalignment.
But it looks as if Tony, Juliano and Matthijs have already discussed that.
Looking at what you found out, it could very well be that changing the used resistors and / or capacitors might do the trick.
- Tony Lindgren tony@atomide.com [170817 21:44]:
I'm still getting memory errors with these quite easilye with two instances of memtester 1900M. But at least the system no longer hangs at 1.35V. The errors seem to start somewhere above 70 C something.
And keeping the temperatures down below 65C with a heat sink and a fan seems to make memtester behave, saw some errors after about half an hour of testing when the cpu temperature got to 68C.
Later,
Tony _______________________________________________ Kernel mailing list Kernel@pyra-handheld.com http://pyra-handheld.com/cgi-bin/mailman/listinfo/kernel
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