Such a thing as 2nd generation PC133 SDRAM Memory?

  • Thread starter Thread starter Oscar G. Carranza
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Oscar G. Carranza

Reason I ask is because I just bought a 256MB PC133 chip off Ebay and it
is only registering as 128 on my system. Just to test I took out my
existing chips and just put the new one in and it still just registers
at 128MB. Emailed the person that sold it to me and he said chip is only
4 months old and is 2nd generation memory. Only newer motherboards will
see it as 256, older ones see it as 128MB. I have an Athlon 700 with the
possible maximum memory at 784MB. I had 384MB with one 128MB and one
256MB on the system. I just want to know if what he says can be true and
if it is how can I tell the difference on memory chips to get the
correct one for my system.

Thanks,
Oscar
 
Yes, he is correct. Your board seems unable
to handle the newer higher density memory.
Go to crucial.com and get the proper memory
for your motherboard. They guarantee it
will work correctly.
 
Oscar G. Carranza said:
Reason I ask is because I just bought a 256MB PC133 chip off Ebay and it
is only registering as 128 on my system. Just to test I took out my
existing chips and just put the new one in and it still just registers
at 128MB. Emailed the person that sold it to me and he said chip is only
4 months old and is 2nd generation memory. Only newer motherboards will
see it as 256, older ones see it as 128MB. I have an Athlon 700 with the
possible maximum memory at 784MB. I had 384MB with one 128MB and one
256MB on the system. I just want to know if what he says can be true and
if it is how can I tell the difference on memory chips to get the
correct one for my system.
Click to expand...
Yes, the older technology used 16MB chips and the newer 32MB chips. So if
your 256MB DIMM contains 8 chips (9 for ECC) then its of the newer type
(sales people call them high density). If it contains 16 chips (18 for ECC)
then its of the older type that works on most mobos.
 
Actually it is quite possibly true, older boards won't recognise all the
memory on some newer dimms, they are configured differently ( higher density
chips I believe?) and this is exactly what happens, the 256 meg dimms appear
as 128.
 
Oscar G. Carranza said:
I just bought a 256MB PC133 chip off Ebay and it is only
registering as 128 on my system.
Emailed the person that sold it to me and he said chip is
only 4 months old and is 2nd generation memory. Only newer
motherboards will see it as 256, older ones see it as 128MB.
I have an Athlon 700 with the possible maximum memory at 784MB.
I had 384MB with one 128MB and one 256MB on the system.
Click to expand...

I don't know about your mobo, but if the mobo was made for PC100
memory, you need PC133 that's also rated for PC100, and few of it is
any more. Some companies, like Crucial, Centon (Circuit City), and
Kingston make distinctions between PC133-only and PC133/PC100 modules,
but others, like PNY/CompUSA and K-byte, do not, and you don't know
what you'll get with them.

It's not enough for a 256MB module to have at least 16 chips on it
because some will still register as only 128MB with older PC100 mobos,
like those based on the Intel 440BX or Socket 7 chipsets. With them
it's also necessary for the chips to "span" no more than 16M x N,
i.e., be 16M x 8, because when I tried a 16-chip 256MB module
containing 32M x 4 chips, only 128MB of it was recognized, except with
my Intel 810-based mobo, which also sees only the first 128MB of
8-chip 256MB modules (and can't use 512MB modules to their full
capacity).
 
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