Re: Mobo memory specs - how to read

Kern wrote:
> I acquired a Via P4X266 PE11-LA board and the user manual that comes with
> it specifies memory types usable as x8/x16 or x64 and there is a chart
> showing example configurations. The highest shown says 64MBx64 512MB.
> It also states that it will support up to 3GB in 3 memory slots.
>
> Now in order to do that it would have to support 1GB memory DDR chips.
> But what I don't know is what the chip configuration on a single stick
> DDR needs to be for this board to work with it (high density or low
> density?).
>
> This uses PC1600 or PC2100 unbuffered DDR SDRAM DIMM memory.
>
> Can someone who understands this please advise? I'd like to maximize
> memory slot usage if possible by putting as much memory in a single
> slot as it will support.
>
> Thank you.

Yeah, some nice confusing terminology on PDF page 7.

http://www.via.com.tw/download/mainb...sa-la_v1.0.pdf

Looks like the board was manufactured by dfi.com.tw . Same font
look to the manual as this.

http://img.lanparty.tw/Upload/Manual/CM/54300150.PDF

*******
Using the motherboard model number, Crucial shows a 1GB stick.
I *presume* this is low density, based on the age of the VIA chipset.
I could not find a way to prove it.

(Low density = (16) 64Mx8 chips, which is double sided and holds
two ranks. One side of the module, or the other side, responds
when the module is accessed.)

http://www.crucial.com/store/mpartsp...B73C47A5CA7304

I cannot find the motherboard on the Kingston site (either under VIA or DFI).
It might have been possible to get a Kingston datasheet for the
stick they recommend, if it was listed.

Which leaves looking on the VIA site, for info on the chipset. And
I'm not expecting much from that.

http://www.via.com.tw/en/products/ch...series/p4x266/

So VIA gives the fuzzy feeling that perhaps 1GB modules work.
But the "density" idea probably wasn't something they needed
to consider, when the chipset came out.

Not a lot to go on.

*******

This is a datasheet from Kingston. This would be a low density
module, since it uses (16) 64Mx8 chips.

http://www.valueram.com/datasheets/KVR400X64C3A_1G.pdf

Just stay away from Ebay, as there is a lot of high density
stuff there, which is (16) 128Mx4 chip modules. Such a
configuration has chips on both sides of the module, but
is single rank. All chips respond at the same time, when
the module is accessed.

One problem with high density, is "half-detected" modules.
If you want, you could buy one Ebay module, and see if
its 1GB of goodness, is detected as "512MB" by your BIOS.
That would tell you the chipset is not capable of addressing the
"128M" part of the chip numbers on the high density module.

That problem has shown up (the half-detected problem), on one
other old VIA chipset. Half-detected is also a problem with
Nforce2 chipset. And these are reasons I try to steer people
away from Ebay, when discussing 1GB DDR modules. It just
isn't worth the hassle, to try to save a few bucks. All
that shipping back and forth and so on. And the sellers
on Ebay know what they're doing - introducing crap RAM
to be sold on forever, in junk sales.

Paul

i wouldn't buy anything off ebay with YOUR money - that place stinks like a port-o-john on comp parts.