John said:
You might be misinterpreting what was said. If your motherboard
already has two sticks/modules, he could have been talking about
the fact that some motherboards have trouble with four sticks of
memory.
I can give an example of that, on my very own computer with
P2B-S motherboard, 440BX chipset, and Celeron (Tualatin) 1100MHz.
It has room for four sticks of RAM. The maximum capacity of
each slot is 256MB. In theory, you're supposed to be able to
install four sticks of 256MB for a total of 1024MB. I tried
that, and the computer crashed. It's a bug in the design
of the motherboard. With two sticks installed, it's perfectly
stable (it ran Prime95 all day without error). With three or
four sticks, it'll crash in about ten minutes. The unstable
part of the machine ends up being the video card (I think it's
AGP related). The more graphic update activity, the sooner it crashes.
I tested with two completely different OSes, and saw the exact
same instability.
Not all 440BX based computers are like that. And it has
nothing to do with "overclocking".
The Crucial site, would recommend 4 * 256MB for my motherboard,
but due to the design bug, it should really only recommend
2 * 256MB. (The RAM was actually bought from Crucial.)
Other 440BX motherboards may be perfectly happy with
all four installed.
On the web, I can find references to what is called the
"Photoshop Bug" for 440BX motherboards. It has to do with
not enough bypass capacitance on the bus termination voltage
supply. But the crashes I was experiencing, weren't the
same as the Photoshop bug. Mine was something else. The
Photoshop bug shows up mainly, while using Photoshop
(long runs of data reads or writes to RAM, with long
sequences of the same data value, causes a shift in the
termination voltage because the capacitor isn't big enough
to prevent the shift). Some people solved the Photoshop bug,
by soldering a capacitor to their motherboard.
If the chipset was something else, the situation could be
entirely different. And perhaps not so prone to problems.
Paul