[ltp] Memory problems on my AP21

[linux-thinkpad@linux-thinkpad.org]

---- Constant Brouerius van Nidek <cbroueriusvannidek@gmail.com> wrote: 
> On Friday 25 April 2008, bhaskins@chartermi.net wrote:
> > ---- Constant Brouerius van Nidek <cbroueriusvannidek@gmail.com> wrote:
> > > On Friday 25 April 2008, Ted Frater wrote:
> > > > Constant Brouerius van Nidek wrote:
> > > > >After one of the two 128MB memory cards of my AP21 broke down, I found
> > > > > a new Kingston 256MB module (KTM-TP390X/256) which according to
> > > > > Kingston is the memory module for my machine.
> >
> > FWIW I have a A21P with two of these  (KTM-TP390X/256) and It has been
> > running fine for years. Memtest86 will run as long as you want it to with
> > no errors.
> 
> Thanks for the info. Do you know if it makes a difference which of the card 
> slots you use if you have only one card?
I don't think so
 And should it matter if I have two 
> cards of different capacity which one is in which slot?
Again, I don't think so.
> In my case I get 384MB if the 256 card is in the left slot and the 128 card in 
> the right. If I reverse their position I get only 64MB. Does this point to 
> the problem of solder joints as Ted suggested?
Your problem may be that the 128 is high density ram or it is of
a different speed than the 256.
Different speeds mean a difference in address line skew and this can
cause "strange" memory problems.
This is the reason why it is best to use chips of the same type and/or
from the same supplier.
I have used the 384 combination many times with no problems
but I have been carefull to use compatible parts. 
> 
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