Trac it. No, we have seen nothing that leads us to believe that we have memory corruption problems w. B2s. Software errors are a much more likely cause.
wad On Nov 23, 2009, at 6:56 PM, Tiago Marques wrote: > On Mon, Nov 23, 2009 at 7:19 PM, John Watlington <[email protected]> > wrote: >> >> On Nov 23, 2009, at 1:55 PM, Tiago Marques wrote: >> >>> On Sun, Nov 22, 2009 at 8:01 PM, Mitch Bradley <[email protected]> >>> wrote: >>>> >>>> Tiago Marques wrote: >>>>> >>>>> Hi, >>>>> >>>>> The hardware page for the XO 1.5 doesn't show the clockspeed of >>>>> the >>>>> RAM chips used. CAS 3 looks like very aggressive timings for cheap >>>>> DDR2 chips. >>>> >>>> CL3 is in spec for the chips that we were using but not for a >>>> new chip >>>> that >>>> we might start using. >>>> >>>>> Are you running at 400 or 533? >>>> >>>> 400 >>>>> >>>>> Doesn't the datasheet specify the appropriate timings? >>>>> >>>> >>>> Of course it does. The jumper is to tell which timing set to use, >>>> depending >>>> on which chips are populated. >>> >>> Ok, I was rather confused when I read: >>> >>> "I switched the timing to CAS latency 4 (from 3), which ** should >>> meet >>> ** specs for this chip." >>> >>> And was finding rather odd that you didn't had access to specified >>> timings. >> >> We have access to the chip timings, and we have information about how >> to program the controller. But it is still a trial and error >> process. >> Nobody likes to manually verify that the programmable DRAM >> controller is >> actually correctly generating the literally hundreds of timing >> specs for a >> given chip. We instead make our best guess at correct values and >> then >> test for proper operation across time and temperature. >> >> In this case, the chips usually worked with the CAS latency set >> too low. >> >> wad >> >> > > Ok, I see. Any chance that that procedure might be causing issues > related to those errors being generated by overheating problems with > B2 hardware? I haven't heard if that has been fixed already. Was it? > My 1.5 B2 crashed yesterday in a rather unexplicable fashion and gave > me some bad data corruption. Haven't been able to reproduce it though, > but it seemed high workload related since I was compiling some > packages on an FS in the external SD. Will try to find out more about > this. > > Best regards, > Tiago Marques > _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
