I suggest that we dedicate the unused memory ID 0 jumper (GPIO9) to indicate that this DRAM is present.
Thanks for reminding me, as Richard and I wanted to add another jumper since we've used them all up. wad On Nov 20, 2009, at 2:51 AM, Mitch Bradley wrote: > I have a B3 with 1 GiB of memory, using Samsung K4T1G084QE RAM chips > which have slightly different timing than the chips we were using. > > Using the old timings, it booted Open Firmware and appeared to > work, but > memtest quickly elicited errors - it started showing them after > about 20 > seconds, during test #2, moving inversions with a constant pattern. > > I switched the timing to CAS latency 4 (from 3), which should meet > specs > for this chip. memtest has been running for 7 minutes with no errors. > I'll leave it running overnight. > > If we are to use this chip, we'll need a way to identify it - perhaps > one of the memory ID straps - unless we want to run the other chips at > CL4 too. > > CL4 has little or no effect on the memcpy speed, but it would slow > down > random reads to a small extent. _______________________________________________ Devel mailing list [email protected] http://lists.laptop.org/listinfo/devel
