Difference in 256mb DIMMs? (help please)

[arswihart]

Could some geek, and I mean that in the most complementary way possible, please give a brief rant on the difference between 16M x 8 DDR SDRAMS and 32M x 8DDR SDRAMs, if I were to be choosing between these two different memory constructions? I see both kinds are utilized in Corsair's 256mb DIMMS, but I have no idea what difference there is, if any. Thanks a lot, I really appreciate any help you can offer.

 

[CurtCold]

"5. What Does ?4x32´ Mean ?

30 pin Parity simms are often referred as 1MB-1x9, 4MB-4x9 and 72 Pin non-parity Simms are often referred as 4MB-1x32, 8MB-2x32 and 72 Pin Parity Simms are often referred as 4MB-1x36, 8MB-2x36. The "1x32" part is the simm specification, also referred to as architecture, because it indicates the simm design in terms of number of chips and density of those chips. If you multiply the 2 numbers out, (E.G 1x32) you get the total number of megabits and then if you divide by 8 (for non-parity) and 9 (Parity) to get the size in megabytes.


Here is a good spot to LOOK

I think the whole high density/low density is just bs. It's basically telling you how the chip is made.

 

[bozo1]

I think the whole high density/low density is just bs. It's basically telling you how the chip is made.

Why BS? Many people are buying high density modules because they are cheap only to find out that they don't work on their boards.

 

[arswihart]

I still don't no what to think. Is there one kind of memory construction that is favored over others, and/or, are there any constructions that are looked down upon? Thanks again for any help, I really appreciate it.

Andrew

 

[Kingofcomputer]

I've posted this hundred times.

There are 2 differnt high density meanings.

1. the real and correct meaning, the size of the ram chip.
for 256Mbit vs 128Mbit, 256Mbit is the higher density ram.
doesn't matter how the ram is built - any Mbit x 4bank x any

2. the wrong meaning, used by pricewatch vendors in the cheap PC133 256MB dimm age.
Such cheap 256MB dimm is double side, total 16 chips, each chip is 128Mbit made by 8Mbit x 4 bank x 4 instead of the normal 4Mbit x 4 bank x 8.
Because of 8Mbit vs 4Mbit, it's called high density.

There are also 2 different bank meanings.

1. the above bank is the bank interleaving inside or between the ram, from 64Mbit ram, all have 4 bank already, one single dimm using 64Mbit ram chips already can do 4-bank interleaving.

2. about how many banks the chipset supports and how many slots on the motherboard, one slot is 2 bank, single side dimm is 1 bank, double side dimm is 2 bank. This bank is not that bank, you don't need 2 double side dimm to get 4-bank interleaving.

 

[arswihart]

I'm sure you all know what you're talking about, but I can't understand hardly anything that's been said. I just don't want to buy an inferior RAM module. I'll ask this one more time, can anyone suggest or caution against any type of RAM module?

I'm getting the feeling "high-density" is the key word. So, will high-density RAM modules provide some benefit, no benefit, or are they in some way inferior to "low-density" RAM chips? If this question is just too complicated, I'm sorry for asking it so many times. Thanks again everyone, I appreciate your contributions.

 

[bozo1]

Bottom line - 256M modules come in 16Mx8 or 32Mx4 (you said 32Mx8 above which I assume is a typo, if not, you would be talking about a 512M module).

Modules using 16Mx8 chips work in most any board that supports PC100/PC133 RAM. 32Mx4 chips, used in a 256M module, are considered 'high-density' and only work in boards that support that type of memory. If your motherboard is based on an Intel chipset, it does not support it. If your board is based on another chipset - Via, Sis, etc. - it may or may not depending on which specific chipset it is.

 

[arswihart]

thanks a lot bozo1 and happy holidays to all

 

[Kingofcomputer]

It's not a typo. The 16Mx8 and 32Mx8 is right.

For the chips on the 256MB dimm,
if it's double side 16 chips, each chip is 16Mbitx8 (4Mbit x 4 bank x 8),
or single side 8 chips, each chip is 32Mbitx8 (8Mbit x 4 bank x 8).

Check the motherboard chipset's tech spec. to see if it supports dimm using 32Mbit x8 chips.
Today's DDR chipsets all should support 32Mbit x8.