Single and Double sided RAM

[Slaimus]

I need to buy 256MB of PC133 for my BX board, which only supports it in double sided form. Is there a way to tell whether a stick of RAM is single or double sided by the label? Does 32x64 always mean single sided 256MB?

 

[Macro2]

look at it. If it has chips on both sides it's double sided. No dohs please.

 

[Peter]

That doesn't mean it's logically double sided. You can have a 16-chip DIMM made from "32x4" SDRAM technology - these have one single logical 256-MByte side formed by those 16 chips (each 4 bit wide).

BX compatible DIMMs look the same, 16 chips on two sides, but use "16x8" SDRAM to form _two_ logical sides 128 MBytes each.

 

[Slaimus]

hmmm, then I guess have to phone in/ask before buying then.

 

[Steve]

They may not know.

If you order online from Crucial, you'll get proper DIMMs specified for your board.

 

[Slaimus]

Originally posted by: Peter
That doesn't mean it's logically double sided. You can have a 16-chip DIMM made from "32x4" SDRAM technology - these have one single logical 256-MByte side formed by those 16 chips (each 4 bit wide).

BX compatible DIMMs look the same, 16 chips on two sides, but use "16x8" SDRAM to form _two_ logical sides 128 MBytes each.

Hmm so double sided can also mean high density? That makes things even more complex...

 

[pspada]

Yea, it's a crapshoot. If it's old double sided ram, it usually works. If it's new, it probably won't work unless it's specifically described as PC100 compatible, sometimes also called Low Density.

Out here it's expensive, over $100 for a 256Mb stick. but readily available, you can message me if you can't find it elsewhere.