PC 133 vs PC 100 in SE440BX-2

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CBFalconer

I notice that Kingston has a specific warning against using PC133
in this machine, and recommends the slower (and more expensive)
PC100 parts. Given that I am not contemplating mixing, but
complete replacement (I want full ECC capabilities) can anybody
explain this warning?
 
CBFalconer said:
I notice that Kingston has a specific warning against using PC133
in this machine, and recommends the slower (and more expensive)
PC100 parts. Given that I am not contemplating mixing, but
complete replacement (I want full ECC capabilities) can anybody
explain this warning?
Click to expand...
Higher-bandwidth devices hear stuff (i.e., noise) that their slower
counterparts don't. My guess is Kingston has learned about problems of
this sort on that board and wants happy customers.
 
I notice that Kingston has a specific warning against using PC133
in this machine, and recommends the slower (and more expensive)
PC100 parts. Given that I am not contemplating mixing, but
complete replacement (I want full ECC capabilities) can anybody
explain this warning?
Click to expand...


Usually they're "meaning" high-density memory when they
refer to it as PC133. It's not technically correct but
apparently they feel it reduces confusion and return rates
from customers. You do need what they call PC100, it is
more expensive because (due to lower density) there are more
chips per module.
 
Higher-bandwidth devices hear stuff (i.e., noise) that their slower
counterparts don't. My guess is Kingston has learned about problems of
this sort on that board and wants happy customers.
Click to expand...

At this stage of the game PC133 and PC100 parts are almost certainly
identical. When a chip manufacturer labels a chip as meeting a certain
speed grade they mean that it is at least that fast, they don't guarantee
that a chip won't exceed a certain speed. Early on in the production of a
chip, when the process is new, they get a range of speeds. They select the
fastest ones and label them with higher speed grades and charge more money
for them. As the process matures the yield curve tightens up. They still
tend to offer the same range of chips but all they are doing is taking the
same chips and marking them with the different grades. SDR SDRAMs are very
old at this stage so all of them are going to come off the line meeting
at least PC133 speeds. If you really want to put more memory in a machine
like that then get the PC133. If I was you I wouldn't put a penny into
hardware that old.
 
At this stage of the game PC133 and PC100 parts are almost certainly
identical. '
Click to expand...

If it weren't for the different densities you'd be right.
Most semi-modern PC100 "spec'd" memory can indeed run at
133MHz. However, memory resellers have done a really odd
twist with PC100 memory, ignoring JEDEC and doing what they
feel reduces RMA by naming it based on what they "think"
people are looking for.

When a chip manufacturer labels a chip as meeting a certain
speed grade they mean that it is at least that fast, they don't guarantee
that a chip won't exceed a certain speed. Early on in the production of a
chip, when the process is new, they get a range of speeds. They select the
fastest ones and label them with higher speed grades and charge more money
for them. As the process matures the yield curve tightens up. They still
tend to offer the same range of chips but all they are doing is taking the
same chips and marking them with the different grades. SDR SDRAMs are very
old at this stage so all of them are going to come off the line meeting
at least PC133 speeds. If you really want to put more memory in a machine
like that then get the PC133. If I was you I wouldn't put a penny into
hardware that old.
Click to expand...

What you wrote is usually true. Howver, OP's chipset cannot
use higher density memory. A 128MB module would be a 16 x 8
configuration for that board, not 32 x 4.

If all else fails he could simply buy it from Crucial.com,
as odds are high they have that board in their memory
configurator or Memory-Advisor or whatever-the-heck they're
calling it these days.
 
General said:
At this stage of the game PC133 and PC100 parts are almost
certainly identical. When a chip manufacturer labels a chip as .... snip ...
at least PC133 speeds. If you really want to put more memory in a
machine like that then get the PC133. If I was you I wouldn't put
a penny into hardware that old.
Click to expand...

There are many reasons for preserving it and its MB. Proper serial
and parallel ports, proper PS2 mouse and keyboard connectors, real
ISA sockets, a genuine reset capability, for example. The machine
is fast enough for my purposes. What I really need is the
reliability of ECC memory, of which the chipset is capable. At the
same time I don't want to invest too much in that memory.
 
kony said:
If it weren't for the different densities you'd be right.
Most semi-modern PC100 "spec'd" memory can indeed run at
133MHz. However, memory resellers have done a really odd
twist with PC100 memory, ignoring JEDEC and doing what they
feel reduces RMA by naming it based on what they "think"
people are looking for.
.... snip ...

What you wrote is usually true. Howver, OP's chipset cannot
use higher density memory. A 128MB module would be a 16 x 8
configuration for that board, not 32 x 4.

If all else fails he could simply buy it from Crucial.com,
as odds are high they have that board in their memory
configurator or Memory-Advisor or whatever-the-heck they're
calling it these days.
Click to expand...

The objective is to not spend excess money. I am only interested
in 256 MB modules with ECC. So if only _some_ PC133 modules won't
function, I need to know how to detect those in advance. Here is
what the manual for the board has to say:

1.3.1 MAIN MEMORY
The motherboard has three DIMM sockets. SDRAM can be installed in
one, two, or three sockets. EDO DIMMs are not supported. Using the
serial presence detect (SPD) data structure, programmed into an
EPROM on the DIMM, the BIOS can determine the SDRAM's size and
speed. Minimum memory size is 16 MB; maximum memory size is 768
MB.
Memory size and speed can vary between sockets.

The motherboard supports the following memory features:
· 168-pin DIMMs with gold-plated contacts
· 66 or 100 MHz SDRAM
· Non-ECC (64-bit) and ECC (72-bit) memory
· 3.3 V memory only
· Unbuffered single- or double-sided DIMMs in the following sizes:

DIMM Non-ECC DIMM SDRAM SDRAM Number of
Capacity Organization* Density Organization SDRAMs
16 MB 2M X 64 16 Mbit 1M X 16 8
16 MB 2M X 64 16 Mbit 2M X 8 8
16 MB 2M X 64 64 Mbit 2M X 32 2
32 MB 4M X 64 16 Mbit 2M X 8 16**
32 MB 4M X 64 64 Mbit 2M X 32 4
32 MB 4M X 64 64 Mbit 4M X 16 4
64 MB 8M X 64 64 Mbit 4M X 16 8
64 MB 8M X 64 64 Mbit 8M X 8 8
128 MB 16M X 64 64 Mbit 8M X 8 16**
256 32M X 64 128 Mbit 16M X 8 8
256 32M X 64 128 Mbit 16M X 8 16**
* ECC DIMM organization will be X 72 and additional components
will be used on each side of DIMM.
** If the number of SDRAMs is greater than nine, the DIMM will
be double sided.

NOTE
Processors with 100 MHz front side bus should be paired only
with 100 MHz SDRAM. Processors with 66 MHz front side bus can
be paired with either 66 MHz or 100 MHz SDRAM.

CAUTION
To be fully compliant with all applicable Intel ® SDRAM memory
specifications, the motherboard should be populated with DIMMs
that support the Serial Presence Detect (SPD) data structure.
If your memory modules do not support SPD, you will see a
notification to this effect on the screen at power up. The
BIOS will attempt to configure the memory controller for normal
operation. However, DIMMs may not function under the determined
frequency. You can access the PC Serial Presence Detect
Specification at:

http://developer.intel.com/technology/memory/pcsdram/spec/index.htm

End of manual quote.
 
OK, folks, read it again and think twice. I saw nothing that said it
_wouldn't_ support PC133 memory. It said it would support either 66 or 100,
and that speeds can be mixed.

Would the board claim to support PC133 memory if it was made before PC133
was available? Probably not. That doesn't mean it won't work, only that
nobody envisioned the combination. I would expect the faster component to
back off and operate at the speed of the slower one, or maybe in this case
to drop the multiplier one notch and operate at 66MHz.

I have that board in a machine I've been playing with, and a couple of
smaller sticks of PC133 memory. If my (human) memory serves me correctly,
some combinations didn't work, not because the speed was incompatible, but
because the memory wasn't SPD capable.

I think maybe I'll go out and try it, one stick at a time, and see if any of
them test out OK.
 
Pelysma said:
I have that board in a machine I've been playing with, and a couple of
smaller sticks of PC133 memory.
Click to expand...

oops, no I don't. The SE440BX went in the recycle bin two weeks ago because
of the Int13h limit. While a BIOS update is undoubtedly available, it
wasn't worth the effort because a better board was handy.

And rereading the OP's original post, it was Kingston, not Intel, that
recommended not using PC133.
 
The objective is to not spend excess money. I am only interested
in 256 MB modules with ECC. So if only _some_ PC133 modules won't
function, I need to know how to detect those in advance. Here is
what the manual for the board has to say:

1.3.1 MAIN MEMORY
The motherboard has three DIMM sockets. SDRAM can be installed in
one, two, or three sockets. EDO DIMMs are not supported. Using the
serial presence detect (SPD) data structure, programmed into an
EPROM on the DIMM, the BIOS can determine the SDRAM's size and
speed. Minimum memory size is 16 MB; maximum memory size is 768
MB.
Memory size and speed can vary between sockets.

The motherboard supports the following memory features:
· 168-pin DIMMs with gold-plated contacts
· 66 or 100 MHz SDRAM
· Non-ECC (64-bit) and ECC (72-bit) memory
· 3.3 V memory only
· Unbuffered single- or double-sided DIMMs in the following sizes:

DIMM Non-ECC DIMM SDRAM SDRAM Number of
Capacity Organization* Density Organization SDRAMs
16 MB 2M X 64 16 Mbit 1M X 16 8
16 MB 2M X 64 16 Mbit 2M X 8 8
16 MB 2M X 64 64 Mbit 2M X 32 2
32 MB 4M X 64 16 Mbit 2M X 8 16**
32 MB 4M X 64 64 Mbit 2M X 32 4
32 MB 4M X 64 64 Mbit 4M X 16 4
64 MB 8M X 64 64 Mbit 4M X 16 8
64 MB 8M X 64 64 Mbit 8M X 8 8
128 MB 16M X 64 64 Mbit 8M X 8 16**
256 32M X 64 128 Mbit 16M X 8 8
256 32M X 64 128 Mbit 16M X 8 16**
* ECC DIMM organization will be X 72 and additional components
will be used on each side of DIMM.
** If the number of SDRAMs is greater than nine, the DIMM will
be double sided.

NOTE
Processors with 100 MHz front side bus should be paired only
with 100 MHz SDRAM. Processors with 66 MHz front side bus can
be paired with either 66 MHz or 100 MHz SDRAM.

CAUTION
To be fully compliant with all applicable Intel ® SDRAM memory
specifications, the motherboard should be populated with DIMMs
that support the Serial Presence Detect (SPD) data structure.
If your memory modules do not support SPD, you will see a
notification to this effect on the screen at power up. The
BIOS will attempt to configure the memory controller for normal
operation. However, DIMMs may not function under the determined
frequency. You can access the PC Serial Presence Detect
Specification at:

http://developer.intel.com/technology/memory/pcsdram/spec/index.htm

End of manual quote.
Click to expand...


The short answer is that Kingston also has a memory
selection tool on their website, which links up to the
following product as compatiblle for your board.


http://www.ec.kingston.com/ecom/configurator/partsinfo.asp?ktcpartno=KVR100X72C2/256

Otherwise, without a website clearly showing the part #s you
are left at the presumption based upon someone's description
of the module. Since SE440BX-2 is among the most popular
motherboards ever made, and used by several OEMS, it should
not be difficult for any memory reseller to guarantee
compatibility if you need to call them and ask about any
module you can't verify as compatible by other means. Of
course this does not exclude running Memtest86 on the
modules' final configuration in the system for at least
several hours, but considering your desire for utmost memory
integrity, even a few days. All boxes I use (even for
non-important, gaming or video encoding) have memtest86 ran
for at least 24 hours.
 
OK, folks, read it again and think twice. I saw nothing that said it
_wouldn't_ support PC133 memory. It said it would support either 66 or 100,
and that speeds can be mixed.

Would the board claim to support PC133 memory if it was made before PC133
was available? Probably not. That doesn't mean it won't work, only that
nobody envisioned the combination. I would expect the faster component to
back off and operate at the speed of the slower one, or maybe in this case
to drop the multiplier one notch and operate at 66MHz.

I have that board in a machine I've been playing with, and a couple of
smaller sticks of PC133 memory. If my (human) memory serves me correctly,
some combinations didn't work, not because the speed was incompatible, but
because the memory wasn't SPD capable.

I think maybe I'll go out and try it, one stick at a time, and see if any of
them test out OK.
Click to expand...

Memory density support is determined by the chipset, and
i440BX did not support high density memory. On many boards
the symptoms of non-support were either failure to POST at
all or only being able to use 1/2 of the module's capacity.
Thi is a known and quite common issue historically speaking,
Google for posts about systems seeing only 1/2 a module.

There were PC133 modules that weren't high-density. It was
a very brief period of time they were available before
manufacturers went to higher density chips for their PC133
offerings.
 
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