On Wed, 7 Oct 2009 13:06:55 +1100
"Gabriel Knight" <(E-Mail Removed)> wrote:

> Hi all
>
> im using a P4SGX-MX mobo that says in the manual it can use ddr pc2700,
> pc2100, pc1600 but I have a 1gig stick of ddr pc3200
>
> can I use this without memory problems? will it run at pc2700?
>
> Thanks
> GK
>
>

The correct answer is... it will probably work, IF the BIOS will recognize 1GB sticks. But you might have to manually set timings for it in the BIOS setup screens.

The problem isn't will it run, but will it be recognized at all? If it's recognized, the RAM will be available for use. But, the BIOS might not choose the right settings (voltage, timings) for it. So even if it works right away, you will want to go into BIOS to double-check the timings settings. -Dave

Hi all

im using a P4SGX-MX mobo that says in the manual it can use ddr pc2700,
pc2100, pc1600 but I have a 1gig stick of ddr pc3200

can I use this without memory problems? will it run at pc2700?

Thanks
GK

Gabriel Knight wrote:
> Hi all
>
> im using a P4SGX-MX mobo that says in the manual it can use ddr pc2700,
> pc2100, pc1600 but I have a 1gig stick of ddr pc3200
>
> can I use this without memory problems? will it run at pc2700?
>
> Thanks
> GK
>

Faster RAM is backward compatible with slower applications. A memory
chip on a DDR3200 stick, can run at speeds below DDR1600, if you
check out a datasheet for the memory chip itself.

The SPD chip on the DIMM, contains timing information. The information
can be used by the BIOS, to work out settings for whatever speed
is to be used. If there were no SPD chip, then, you might have a problem.

In terms of purchasing 1GB DDR modules from Ebay, stay away from
the "high density" formulation, with a table in the advert which
states which chipsets are "compatible". A good RAM product, should
work interchangeably, and not be restricted to a subset of chipsets.
The modules in question, may be made with 128Mx4 chips, rather than
64Mx8. The sixteen 128Mx4 chips sit in one rank, instead of the
more normal double rank of eight 64Mx8 chips. This apparently
causes some loading problems. The increased addressing requirement
(128M address space via multiplexed row and column address), is
also not supported by some chipsets. For example, my Nforce2 board
would only see a 512MB DIMM, if I plugged in that Ebay module.

If you got a more normal, branded RAM, then you shouldn't have
a problem.

Example of a module with (16) 64Mx8 chips.

http://www.valueram.com/datasheets/KHX3200_1G.pdf

Paul

Gabriel Knight wrote:

> im using a P4SGX-MX mobo that says in the manual it can use ddr pc2700,
> pc2100, pc1600 but I have a 1gig stick of ddr pc3200
>
> can I use this without memory problems? will it run at pc2700?

I had an ECS P4S5A mobo, based on the SiS 645 chipset (your P4SGX-MX
uses the SiS 650 chipset), and it and an ECS K7S5A Pro (SiS 735
chipset), both made for PC2100 DDR maximum speed memory, worked fine
with PC3200 unless I selected the safe defaults in the BIOS setup, in
which case it just beeped and gave a blank screen. With the other
defaults (optimized, CMOS cleared with jumper or battery removal) the
PC3200 memory worked fine.

Test the PC3200 memory overnight with MemTest86 ver. 3.xx
(www.memtest86.com) AND Gold Memory 5.07 (www.goldmemory.cz). There's
a lot of junk out there, even with major memory brands (most of my
Kingston 512MB PC3200 modules failed testing).