P4T533C Memory Issues. Any help would be great.

[Racer X]

I have 2 sticks of Kingston KVR1066X18-8/256 RDRAM in my ASUS P4T533C. I
believe that these are 16-bit ECC 184 pin modules. I would like to add
another 512MB of memory but I have a few questions first.

Can I mix non-ECC memory with the Kingston ECC?
What is the equivalent Samsung module? I think that it is the MR18R1628DF0
but I'm not quite sure.
What is the difference between 16-bit and 32-bit? Can I mix the two types?
What is Dual Channel RDRAM?
What type of memory would you suggest and where can I buy it?

Thanks so much...There are some very helpful people here.

 

[Paul]

I have 2 sticks of Kingston KVR1066X18-8/256 RDRAM in my ASUS P4T533C. I
believe that these are 16-bit ECC 184 pin modules. I would like to add
another 512MB of memory but I have a few questions first.

Can I mix non-ECC memory with the Kingston ECC?
What is the equivalent Samsung module? I think that it is the MR18R1628DF0
but I'm not quite sure.
What is the difference between 16-bit and 32-bit? Can I mix the two types?
What is Dual Channel RDRAM?
What type of memory would you suggest and where can I buy it?

Thanks so much...There are some very helpful people here.

http://www.anandtech.com/memory/showdoc.aspx?i=1239&p=3

P4T533 2 sockets, dual channel, RIMM4200, RIMM3200
- 32 bit Rambus. 232 pin package.
- 850E Northbridge
P4T533c 4 sockets, dual channel, PC1066, PC800
- 16 bit Rambus, 184 pin package.
- 850E Northbridge

ftp://download.intel.com/design/chipsets/datashts/29069104.pdf

It would seem, that in the case of the 32 bit RDRAM modules,
the two channels operate from the same module. There are only
32 data signals on the 850E, so when it is using 16 bit modules,
two modules work in parallel, and when it is using 32 bit modules,
a single module satisfies both channels at the same time. Data
moves serially through the module, so I think there is a bus
connection, eight chips tied head to tail, then another bus
connection on the edge of the module, that goes to the next
module. That is why continuity modules are required in unused
slots. The "T" below stands for some kind of terminator,
presumably the terminator resistors are on the motherboard
somewhere.

P4T533c P4T533
16 bit 16 bit 16 bit 16 bit
| | | | | | | |
184pinModule 184pinModule 232pinModule
| | | | | | | |
184pinModule 184pinModule 232pinModule
T T T T T T T T

The QVL for the 232 pin modules is here:
http://www.asus.com/prog/spec.asp?m=P4T533&langs=01

Your P4T533c and its 184 pin modules:
http://www.asus.com/prog/spec.asp?m=P4T533-c&langs=01

Vendor Type Size ECC Type Model
/NonECC
Samsung 1066 256MB ECC 8d MR18R1628AF1-CN9
Samsung 1066 128MB ECC 4d MR18R1624AF1-CN9
Samsung 1066 128MB nonECC 4d MR16R1624DF0-CT9
Samsung 1066 256MB nonECC 8d MR16R1628DF0-CT9
Samsung 1066 512MB nonECC 16d MR16R162GDF0-CT9

Kingston info is not on the site currently, but is available
from web.archive.org

(old pricing)
http://web.archive.org/web/20030210123142/www.valueram.com/config/type_parts.asp?type=rimm

(datasheets)
http://web.archive.org/web/20030201082702/www.valueram.com/resources/datasheets.asp

(your module - 8 device - each device has an ECC bit)
http://web.archive.org/web/20030201082702/http://www.valueram.com/datasheets/KVR1066X18_8_256.pdf

I can find an archive of a Samsung module web page, but the datasheets
weren't archived, I guess. Try looking in the "normal" section.

http://web.archive.org/web/20021001072315/www.samsungelectronics.com/semiconductors/DRAM/DRAM.htm

It is possible there is product out there which is inappropriate for your
board, so proceed carefully. For example, there are 32 ns modules for
1066, and there are slower modules, so beware of Ebay sellers trying
to get rid of crap.

Barry Watzman is the guy you want to ping. His email address in Google,
consists of his last name and neo.rr.com as the domain. He drops in here
occasionally, but perhaps email might be faster. He might know what Samsung
modules bear a resemblance to your Kingston modules. Unless I can find a
cache of Samsung datasheets somewhere, I cannot tell one from another.
Barry has bought a lot of RDRAM off Ebay.

HTH,
Paul

 

[Racer X]

Paul,
You are unbelievable!!
Thanks so much for your attention to this matter. It was a great help.

 

[Barry Watzman]

The P4T533-C uses 16-bit RDRAM modules (184 pins), the P4T533 (no-C) use
32-bit modules (232 pins). 16 bit modules are always used in pairs in
P4 systems (but singly in Pentium 3 systems), and P4 motherboards using
them have 4 sockets (e.g. 1 or 2 pairs). The 32-bit modules are used
singly, and motherboards that use them only have 2 sockets.

You can tell the module width because the 232-pin sockets have pins in
the middle and only one notch (unless someone has cut out the space for
a 2nd notch, trying to use the 232-bit module in a 184-pin motherboard.
This won't work, but if it's done carefully, it won't damage the
module). The 184 pin modules have 2 notches and an "empty" area (no
pins) between them, in the middle.

In all cases, empty slots must be filled with C-RIMM terminator modules
(which are different for 16-bit vs. 32-bit modules).

Paul's comments about the architecture of the 32-bit modules and how
they work is incorrect, but the explanation is too complex to go into
here (and, fortunately, is irrelevant to the end-user).

Generally, the modules within a pair must be architecturally identical
(including the number of chips per module, see below), but the two pairs
can be different. I'm not 100.0% sure that applies to ECC, but it does
apply to most everything else. [In other words, I THINK you can have
one pair of ECC and one pair of non-ECC, but I'm not certain -- and it
may depend on the BIOS, because you may need to turn off the ECC
manually to do so].

As to other parameters, there are only a few that matter:

-Total module size must be matched between the two modules within a pair
but may be different between the pairs. For example, you can mix two
128's and two 256's to get 768 megs of total memory.

-"PC" speed -- You need PC800 for a CPU with a 100/400MHz front side
bus, or PC1066 for a 133/533MHz front side bus.

-Access time -- For a 100/400 FSB on an Intel 850 chipset, 45 nSec is
adequate, but for an 850e, you need 40 nSec (both designated as
"PC800"). For PC1066, you need 32 nSec (there are some 35 nSec PC1066
modules, avoid them). Faster access times (smaller numbers) are
"backwards compatible".

-Internal module architecture - this is occasionally, but rarely,
relevant. For example, a 128 meg module can be made with eight chips of
16 megs each or 4 chips of 32 megs each. This only if you are going for
really high memory capacity (there is a limit on the total number of
chips, but it's fairly high -- 32, I think). Other things being equal,
modules of the same size with fewer chips are better (but, on the other
hand, 820 and 840 chipsets (Pentium III) can't recognize the newer,
largest chips, and in all cases, this needs to be matched between the
modules comprising a pair). This is shown as 128/8 or 128/4, where the
number after the slash give you the number of chips inside the module.

Hope that helps.

 

[Paul]

The P4T533-C uses 16-bit RDRAM modules (184 pins), the P4T533 (no-C) use
32-bit modules (232 pins). 16 bit modules are always used in pairs in
P4 systems (but singly in Pentium 3 systems), and P4 motherboards using
them have 4 sockets (e.g. 1 or 2 pairs). The 32-bit modules are used
singly, and motherboards that use them only have 2 sockets.

You can tell the module width because the 232-pin sockets have pins in
the middle and only one notch (unless someone has cut out the space for
a 2nd notch, trying to use the 232-bit module in a 184-pin motherboard.
This won't work, but if it's done carefully, it won't damage the
module). The 184 pin modules have 2 notches and an "empty" area (no
pins) between them, in the middle.

In all cases, empty slots must be filled with C-RIMM terminator modules
(which are different for 16-bit vs. 32-bit modules).

Paul's comments about the architecture of the 32-bit modules and how
they work is incorrect, but the explanation is too complex to go into
here (and, fortunately, is irrelevant to the end-user).

Generally, the modules within a pair must be architecturally identical
(including the number of chips per module, see below), but the two pairs
can be different. I'm not 100.0% sure that applies to ECC, but it does
apply to most everything else. [In other words, I THINK you can have
one pair of ECC and one pair of non-ECC, but I'm not certain -- and it
may depend on the BIOS, because you may need to turn off the ECC
manually to do so].

As to other parameters, there are only a few that matter:

-Total module size must be matched between the two modules within a pair
but may be different between the pairs. For example, you can mix two
128's and two 256's to get 768 megs of total memory.

-"PC" speed -- You need PC800 for a CPU with a 100/400MHz front side
bus, or PC1066 for a 133/533MHz front side bus.

-Access time -- For a 100/400 FSB on an Intel 850 chipset, 45 nSec is
adequate, but for an 850e, you need 40 nSec (both designated as
"PC800"). For PC1066, you need 32 nSec (there are some 35 nSec PC1066
modules, avoid them). Faster access times (smaller numbers) are
"backwards compatible".

-Internal module architecture - this is occasionally, but rarely,
relevant. For example, a 128 meg module can be made with eight chips of
16 megs each or 4 chips of 32 megs each. This only if you are going for
really high memory capacity (there is a limit on the total number of
chips, but it's fairly high -- 32, I think). Other things being equal,
modules of the same size with fewer chips are better (but, on the other
hand, 820 and 840 chipsets (Pentium III) can't recognize the newer,
largest chips, and in all cases, this needs to be matched between the
modules comprising a pair). This is shown as 128/8 or 128/4, where the
number after the slash give you the number of chips inside the module.

Hope that helps.

I love a challenge, Barry

Perhaps my mistake on the 32 bit modules, is the fact that the
termination is on the module ?

http://rambus.com/products/rdram/documentation/32BitRIMM_w256Mb_d_0164_V0_1.pdf

That datasheet suggests the wiring looks like:

P4T533c P4T533

16 bit 16 bit 16 bit
| | | | | | T T
184pinModule 184pinModule 232pinModule
| | | | | | | |
184pinModule 184pinModule 232pinModule
T T T T T T | |
16 bit

On the 232 pin module, there are only three 16 bit busses. By connecting
the modules back to back, and limiting the architecture to a two
module pair, the need for a fourth 16 bit bus is avoided.

References:

Page 7 shows the pinout of a 232 pin module, and suggested the connection
diagram on the right above...
http://rambus.com/products/rdram/documentation/32BitRIMM_w256Mb_d_0164_V0_1.pdf

Page 5 shows the pinout of a 184 pin module, and suggests to me the
connectivity on the left of the diagram above.
http://rambus.com/downloads/RIMM256_d_0110_V1_1.pdf

This Intel reference schematic verifies the left diagram. There are
two channels, with two RIMMs each.
page15 (850) ch1 --> page18 (rimm1) --> page 20 (rimm2 + ext 28ohm term)
page15 (850) ch2 --> page19 (rimm1) --> page 21 (rimm2 + ext 28ohm term)

ftp://download.intel.com/design/chipsets/designex/298245_CRB.pdf

I cannot find an Intel ref schematic for the P4T533 type design.

Another thing I'm having trouble with, is understanding the
pinout of the 184pin module. The P4T533-C has the two modules
in a channel oriented the same, as opposed to having the modules
facing one another. And yet, if you look at the copper on the
PCB, the signals look like they just flow through. That means
the use of "L" and "R" between the two modules in a channel
isn't consistent, and looks something like this:

P4T533c P4T533

16 bit 16 bit 16 bit
| | | | | |
A2 L| | | | | | T T <--on module
184pinModule 184pinModule 232pinModule
A83 R| | | | | | | |
A83 R| | | | | | | |
184pinModule 184pinModule 232pinModule
A2 L| | | | T T | |
T T T T <-- on mobo | |
16 bit

Compare to the motherboard pictures in the manuals:
http://www.asus.com/pub/ASUS/mb/sock478/p4t533/e1152_p4t533.pdf (pg.17)
http://www.asus.com/pub/ASUS/mb/sock478/p4t533-c/e1151_p4t533-c.pdf (pg.17)

Great fun!
Paul

 

[Barry Watzman]

Each module has one terminated channel, one unterminated channel. The
modules are arranged (installed) in "opposite directions" (physically,
although they are parallel to each other on the board, one is "flipped"
relative to the other -- one is "face up", if you will, the other is
"face down"). Each module terminates the channel that is unterminated
on the other module. Both modules are identical, and a terminator
module terminates the same "channel" as a live module. Beyond that,
it's not easy to explain without being able to sit down together with a
piece of paper at a table.

The P4T533-C uses 16-bit RDRAM modules (184 pins), the P4T533 (no-C) use
32-bit modules (232 pins). 16 bit modules are always used in pairs in
P4 systems (but singly in Pentium 3 systems), and P4 motherboards using
them have 4 sockets (e.g. 1 or 2 pairs). The 32-bit modules are used
singly, and motherboards that use them only have 2 sockets.

You can tell the module width because the 232-pin sockets have pins in
the middle and only one notch (unless someone has cut out the space for
a 2nd notch, trying to use the 232-bit module in a 184-pin motherboard.
This won't work, but if it's done carefully, it won't damage the
module). The 184 pin modules have 2 notches and an "empty" area (no
pins) between them, in the middle.

In all cases, empty slots must be filled with C-RIMM terminator modules
(which are different for 16-bit vs. 32-bit modules).

Paul's comments about the architecture of the 32-bit modules and how
they work is incorrect, but the explanation is too complex to go into
here (and, fortunately, is irrelevant to the end-user).

Generally, the modules within a pair must be architecturally identical
(including the number of chips per module, see below), but the two pairs
can be different. I'm not 100.0% sure that applies to ECC, but it does
apply to most everything else. [In other words, I THINK you can have
one pair of ECC and one pair of non-ECC, but I'm not certain -- and it
may depend on the BIOS, because you may need to turn off the ECC
manually to do so].

As to other parameters, there are only a few that matter:

-Total module size must be matched between the two modules within a pair
but may be different between the pairs. For example, you can mix two
128's and two 256's to get 768 megs of total memory.

-"PC" speed -- You need PC800 for a CPU with a 100/400MHz front side
bus, or PC1066 for a 133/533MHz front side bus.

-Access time -- For a 100/400 FSB on an Intel 850 chipset, 45 nSec is
adequate, but for an 850e, you need 40 nSec (both designated as
"PC800"). For PC1066, you need 32 nSec (there are some 35 nSec PC1066
modules, avoid them). Faster access times (smaller numbers) are
"backwards compatible".

-Internal module architecture - this is occasionally, but rarely,
relevant. For example, a 128 meg module can be made with eight chips of
16 megs each or 4 chips of 32 megs each. This only if you are going for
really high memory capacity (there is a limit on the total number of
chips, but it's fairly high -- 32, I think). Other things being equal,
modules of the same size with fewer chips are better (but, on the other
hand, 820 and 840 chipsets (Pentium III) can't recognize the newer,
largest chips, and in all cases, this needs to be matched between the
modules comprising a pair). This is shown as 128/8 or 128/4, where the
number after the slash give you the number of chips inside the module.

Hope that helps.

I love a challenge, Barry

Perhaps my mistake on the 32 bit modules, is the fact that the
termination is on the module ?

http://rambus.com/products/rdram/documentation/32BitRIMM_w256Mb_d_0164_V0_1.pdf

That datasheet suggests the wiring looks like:

P4T533c P4T533

16 bit 16 bit 16 bit
| | | | | | T T
184pinModule 184pinModule 232pinModule
| | | | | | | |
184pinModule 184pinModule 232pinModule
T T T T T T | |
16 bit

On the 232 pin module, there are only three 16 bit busses. By connecting
the modules back to back, and limiting the architecture to a two
module pair, the need for a fourth 16 bit bus is avoided.

References:

Page 7 shows the pinout of a 232 pin module, and suggested the connection
diagram on the right above...
http://rambus.com/products/rdram/documentation/32BitRIMM_w256Mb_d_0164_V0_1.pdf

Page 5 shows the pinout of a 184 pin module, and suggests to me the
connectivity on the left of the diagram above.
http://rambus.com/downloads/RIMM256_d_0110_V1_1.pdf

This Intel reference schematic verifies the left diagram. There are
two channels, with two RIMMs each.
page15 (850) ch1 --> page18 (rimm1) --> page 20 (rimm2 + ext 28ohm term)
page15 (850) ch2 --> page19 (rimm1) --> page 21 (rimm2 + ext 28ohm term)

ftp://download.intel.com/design/chipsets/designex/298245_CRB.pdf

I cannot find an Intel ref schematic for the P4T533 type design.

Another thing I'm having trouble with, is understanding the
pinout of the 184pin module. The P4T533-C has the two modules
in a channel oriented the same, as opposed to having the modules
facing one another. And yet, if you look at the copper on the
PCB, the signals look like they just flow through. That means
the use of "L" and "R" between the two modules in a channel
isn't consistent, and looks something like this:

P4T533c P4T533

16 bit 16 bit 16 bit
| | | | | |
A2 L| | | | | | T T <--on module
184pinModule 184pinModule 232pinModule
A83 R| | | | | | | |
A83 R| | | | | | | |
184pinModule 184pinModule 232pinModule
A2 L| | | | T T | |
T T T T <-- on mobo | |
16 bit

Compare to the motherboard pictures in the manuals:
http://www.asus.com/pub/ASUS/mb/sock478/p4t533/e1152_p4t533.pdf (pg.17)
http://www.asus.com/pub/ASUS/mb/sock478/p4t533-c/e1151_p4t533-c.pdf (pg.17)

Great fun!
Paul