Single / duel banked sdram ?

[General Winters]

Win 98 , unknown Quantex series, using biostar m6tba motherboard

My obsolete computer originally came with 64mb of memory, 4 chips on a single side of the stick, pc100.

I soon upgraded to 128 mb, pc133 and since the manual stated a 128 and 64 could not be used together I put the 64 mb aside and forgot about it . The new stick had 8 chips on each side (so was double banked?) and worked perfectly .

Now , years later the system still worked and I wanted to upgrade to the maximum 384mb so bought 2 new sticks of 128mb , pc133 ( the last the shop had!). These sticks are different from the old 128 mb , they are single sided and have only 4 chips ..

Now the problem is these sticks only give 64mb each in any possible combination , whether alone or in combination with the others. I found my old 64mb chip and it still works , with the 2 new chips it gives 64+64+64!

Aida32 recognizes the new chips as 128 mb,

[ SPD ]
[ 128 MB PC133 SDRAM ]

Memory Module Properties:
Module Size 128 MB (1 rows, 4 banks)
Module Type Unbuffered
Memory Type SDRAM
Memory Speed PC133 (133 MHz)

But shows memory to be only 64 mb
[ Memory ]
Physical Memory:
Total 64 MB

Bios only shows 64 also , so a single chip shows as 64, 2 as 128 and old + 2 new = 256

I don't have onboard video so thats not eating the ram.

So , it seems only double sided 128 mb chips function correctly, although single sided 64mb function ok .. The motherboard manual shows pics of single / double sided sdram but makes no other comment .


Now , how do I buy more double sided 128mb sticks? The online sites never mention whether a stick is single or double sided , just obscure configurations such as 16x64 (128)? Is this a double sided 128 mb chip ?

What do I need to look for to get a double sided , 128mb pc133 chip ??

[DrMDJ]

You're problem isn't the sticks being single or double sided, its that the (individual) chip density on the last 2 sticks you bought is too high relative to what your motherboard can handle. The maximum (what's called) component density (ie. megabits per chip) for the memory modules your board can use is 128megabits. In your case (where you wanted 2- 128MB sticks) you wanted modules in the 16x64 configuration.

What you want is shown here.

[General Winters]

Hey , thanks!