If you really have a P4T533, it uses 232-pin 32-bit RDRAM, RIMM 3200
(PC800) can be used with a 400 MHz FSB CPU, but normally these
motherboards use RIMM 4200 (PC1066) with 533 MHz CPUs.
You do not need to "match" the existing memory exactly. In fact, the
whole point of the 32-bit RDRAM is that you don't install them in pairs,
and that you can have one 256 meg module and one 512 meg module, for
example, giving 768 megs or total memory. But you do need to match the
basic type of memory (232-pin, 32-bit wide RDRAM, RIMM 4200, and some of
the timing specs).
Samsung and Elpida are the only ones actually making RIMM 4200 RDRAM at
this point, although it's sold (and private labeled) by Muskin, OCZ and
a few others. Personally, I'd go with Samsung branded memory, it's the
best memory that there is, in my opinion (certainly RDRAM, but I'd say
that it's probably the best memory of almost any type).
As to AIDA's report, you can ignore that. The chipset is an Intel 850e,
and that same chipset will work with either 16-bit or 32-bit wide RDRAM,
the chipset does not know or care, and neither the chipset nor AIDA have
any way to determine, really, the type of memory (16-bit or 32-bit)
actually connected to the chipset. The only difference between 16-bit
and 32-bit RDRAM is packaging, the 32-bit stuff is just two logical
modules on a single "stick" of memory, but the motherboard then only has
2 sockets and not four.
You should be able to get a 256 meg module (giving you 512 of total
memory) for around $70 to $90. In fact I've seen them go on E-Bay (and
I've bought 7 of them) for as low as $35 or so. However, the large
modules (512 megs) are both rare and [disproportionately] expensive. On
E-Bay, these are often sold in pairs, although with this type of memory,
you do not have to install them in pairs. You do, however, need to
install a 232-pin C-RIMM terminator into the empty socket if there is one.
In terms of Samsung part numbers, you will find parts with "AF0" and
"DF0" and with "CN9" and "CT9", but as far as I've been able to
determine, they will all work (and are all listed as approved in the
downloaded version of the manual).
The P4T533 is an excellent motherboard, in fact I prefer it to anything
else available, although it can't support the 800 MHz FSB CPUs and to
get Hyperthreading you must use the 3.06 GHz CPU. Because it's memory
system is faster than DDR 800, it will essentially hold it's own against
an 800 MHz FSB system with a CPU of the same speed, and I think it's a
bit more stable and reliable. So I'm sticking with the P4T533 at least
until Prescott comes out next year. Note that some of the early P4T533s
had a problem apparently in the CPU Vcore power supply, the best ones
have serial numbers from at least October of 2002 or later (that is, 2A,
2B, 2C or 3-anything), and have a small fan on the chipset heatsink.
The power supply problem, when it is present, sometimes doesn't show up
with slower CPUs but does show up when you upgrade to faster CPUs,
especially 2.8 and 3.06 GHz, which require much more current.
Note also that the P4T533 and the P4T533-C motherboards are TOTALLY
different, and that this post applies only to the P4T533 (without the
"-C" suffix).
