Max size limit on MicroDIMM memory modules?

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Ethics Forge

Can someone tell me (or link me to someplace that will explain it) why
144pin MicroDIMM (non-ddr) PC100/PC133 modules only seem to go up to
256MB? I for the life of me can't find what, if any, technical
limitation there is, and am curious if it is a technical or market
limitation that makes them only be available up to 256MB.
 
Can someone tell me (or link me to someplace that will explain it) why
144pin MicroDIMM (non-ddr) PC100/PC133 modules only seem to go up to
256MB? I for the life of me can't find what, if any, technical
limitation there is, and am curious if it is a technical or market
limitation that makes them only be available up to 256MB.
Click to expand...

Umm, they do go up to 512MB - check out www.crucial.com for SO-DIMMs,
assuming that's what you meant. Some mfrs may have just decided not to go
to the bother of the special chip packaging for 265M-bit chips or doing
SO-DIMMs using the 512M-bit chips... hardly a volume market.
 
No, I said, and I meant, MicroDIMM - it is smaller then SO-DIMM, and
generally used in subnotebooks
 
Can someone tell me (or link me to someplace that will explain it) why
144pin MicroDIMM (non-ddr) PC100/PC133 modules only seem to go up to
256MB? I for the life of me can't find what, if any, technical
limitation there is, and am curious if it is a technical or market
limitation that makes them only be available up to 256MB.
Click to expand...

I think most manufacturers just don't see much of a market for laptops
that old. So microDIMMs just don't get any bigger than whatever is the
largest at the point the technology got overtaken by DDR and now DDR2.
They just don't bother to make memory chips of higher density for the
older standard.
 
I think most manufacturers just don't see much of a market for laptops
that old. So microDIMMs just don't get any bigger than whatever is the
largest at the point the technology got overtaken by DDR and now DDR2.
They just don't bother to make memory chips of higher density for the
older standard.
Click to expand...

Might be much simpler than that. Perhaps the architecture of the chipsets used
with pc100/pc133 drams simply didn't/don't support more capacity-per-dimm...

/daytripper
 
No, I said, and I meant, MicroDIMM - it is smaller then SO-DIMM, and
generally used in subnotebooks
Click to expand...

Sorry but I've never messed with sub-notebooks. See my 2nd sentence then:
the packaging and chips to allow this form factor at that size was at the
end of the SDRAM era.
 
I think most manufacturers just don't see much of a market for laptops
that old. So microDIMMs just don't get any bigger than whatever is the
largest at the point the technology got overtaken by DDR and now DDR2.
They just don't bother to make memory chips of higher density for the
older standard.
Click to expand...

True about the changeover to DDR but PC-133 SDRAM 512Mb chips are available
now - apart from just the economics, I think it's more to do with the
packaging: FBGA was just being adopted for commodity DRAMs at about the
same time as DDR took over. I also recall the 512MB PC-133 SO-DIMMs I
purchased had the chips in a very strange package... looked like a blob of
asphalt glued to the DIMM substrate, 4 per side and probably would not have
fit on a MicroDimm.
 
True about the changeover to DDR but PC-133 SDRAM 512Mb chips are available
now - apart from just the economics, I think it's more to do with the
packaging: FBGA was just being adopted for commodity DRAMs at about the
same time as DDR took over. I also recall the 512MB PC-133 SO-DIMMs I
purchased had the chips in a very strange package... looked like a blob of
asphalt glued to the DIMM substrate, 4 per side and probably would not have
fit on a MicroDimm.
Click to expand...

But that's largely economics no? I'm sure they would had found a way
to fit it if they really wanted to. After all, there are DDR 512MB
microDIMMs, just not for PC100/PC133.

However, of course daytripper's comment about the chipset limitations
is probably the main thing :PpP
 
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