XP DDR memory not listed correctly

[- Bobb -]

My daily pc has 1gb DDR400 (2 512mb sticks)
I was tossing an old PC and took it's memory to add here, so I added another
1gb DDR400 last night (2 -512's) and when I rebooted it shows as DDR333 in
splash screen / XP .
I gotta run now, but wondering - other than reseat/swap around to isolate
etc, any tricks for troubleshooting why speed shows as incorrect ? I've
never run into this before.

Thanks

 

[David H. Lipman]

My daily pc has 1gb DDR400 (2 512mb sticks)
I was tossing an old PC and took it's memory to add here, so I added another 1gb DDR400
last night (2 -512's) and when I rebooted it shows as DDR333 in splash screen / XP .
I gotta run now, but wondering - other than reseat/swap around to isolate etc, any
tricks for troubleshooting why speed shows as incorrect ? I've never run into this
before.

Thanks

Upgrade the BIOS. It may not be recognizing the PC3200 RAM.

 

[Paul]

My daily pc has 1gb DDR400 (2 512mb sticks)
I was tossing an old PC and took it's memory to add here, so I added another
1gb DDR400 last night (2 -512's) and when I rebooted it shows as DDR333 in
splash screen / XP .
I gotta run now, but wondering - other than reseat/swap around to isolate
etc, any tricks for troubleshooting why speed shows as incorrect ? I've
never run into this before.

Thanks

Your system has an AMD processor, and this is normal.

Clock speed is turned down on the RAM bus, when moving from
two sticks to four sticks. The load compensation changes the
system from DDR400 to DDR333 speed setting.

Later RAM standards (DDR2/DDR3 versus your DDR), don't have
this problem to nearly the same extent.

You can use some custom RAM settings, to try to work around it,
but then you need to do careful RAM testing before using the
system for serious work.

Paul

 

[VanguardLH]

My daily pc has 1gb DDR400 (2 512mb sticks) I was tossing an old PC
and took it's memory to add here, so I added another 1gb DDR400 last
night (2 -512's) and when I rebooted it shows as DDR333 in splash
screen / XP .

Some mobos have to reduce their clock rate when you populate, say, more
than 3 memory slots. The mobo cannot support the extra load (power) at
the higher clock rate. Another restriction may be that you lose dual
channel mode if you go with more than 2 modules (i.e. more than 1 bank).
Just because the mobo has 4 slots doesn't mean there isn't a consequence
of populating more than 2 of them.

You never mentioned the brand and model of mobo. Read its manual on
memory support to see if there are restrictions or reductions incurred
on memory configurations. Sometimes they just mention in a paragraph
the restrictions. Sometimes they provide a table showing what works
with what config.


NOTE: For future reference and posting, when cross-posting to multiple
newsgroups, they should be related. This is not a OS (Windows XP) issue
but instead a hardware issue. The correct cross-post group is
microsoft.public.windowsxp.hardware, not the windowsxp.general group.

 

[Paul]

Where did the OP mention that detail? Where do you see any details
regarding their mobo? Where do you see the brand and model specified?

I deduced it all, and await confirmation of the missing details.

Only AMD does this.

My Intel chipset DDR400 motherboard has no such penalty, and
that's how I know the processor is AMD. I can stick two or four
matched sticks in the 875P based motherboard, and it always runs
at DDR400. There was a claim that chipset runs Command Rate 2
under all conditions, but without an exposed BIOS setting,
it's hard to know that for sure. Lots of stuff about chipsets,
can only be determined with an oscilloscope (due to the limitations
of what is stated in data sheets).

The OP stated a transition from two sticks to four sticks, and
a change from DDR400 automatically to DDR333. And that pattern
matches AMD S939 processors.

Paul

 

[Yousuf Khan]

My daily pc has 1gb DDR400 (2 512mb sticks)
I was tossing an old PC and took it's memory to add here, so I added another
1gb DDR400 last night (2 -512's) and when I rebooted it shows as DDR333 in
splash screen / XP .
I gotta run now, but wondering - other than reseat/swap around to isolate
etc, any tricks for troubleshooting why speed shows as incorrect ? I've
never run into this before.

Do all 4 sticks show as DDR333, or do some show as DDR333 while others
show DDR400?

What I would do is boot up with only the newer pair, and see if those by
themselves show up as DDR400. If not, then there might be some
incompatibility between them and your system.

Yousuf Khan

 

[- Bobb -]

I deduced it all, and await confirmation of the missing details.

Only AMD does this.

My Intel chipset DDR400 motherboard has no such penalty, and
that's how I know the processor is AMD. I can stick two or four
matched sticks in the 875P based motherboard, and it always runs
at DDR400. There was a claim that chipset runs Command Rate 2
under all conditions, but without an exposed BIOS setting,
it's hard to know that for sure. Lots of stuff about chipsets,
can only be determined with an oscilloscope (due to the limitations
of what is stated in data sheets).

The OP stated a transition from two sticks to four sticks, and
a change from DDR400 automatically to DDR333. And that pattern
matches AMD S939 processors.

Paul

EXACTLY right !
ASUS mb with an AMD 939 cpu. Boy, am I glad I asked here first. It made no
sense to me that 2 sticks to 4 would change clock speed. I don't NEED 2gb
but I was tossing a few Celeron PC's and took their DDR400 mem sticks and
stuck them in here rather than recycle it all.

Thanks very much.

 

[- Bobb -]

....
NOTE: For future reference and posting, when cross-posting to multiple
newsgroups, they should be related. This is not a OS (Windows XP) issue
but instead a hardware issue. The correct cross-post group is
microsoft.public.windowsxp.hardware, not the windowsxp.general group.

Sorry but I didn't know of the .hardware group - I had used/mapped the xp
group though.

 

[glee]

I deduced it all, and await confirmation of the missing details.

Only AMD does this.

My Intel chipset DDR400 motherboard has no such penalty, and
that's how I know the processor is AMD. I can stick two or four
matched sticks in the 875P based motherboard, and it always runs
at DDR400. There was a claim that chipset runs Command Rate 2
under all conditions, but without an exposed BIOS setting,
it's hard to know that for sure. Lots of stuff about chipsets,
can only be determined with an oscilloscope (due to the limitations
of what is stated in data sheets).

The OP stated a transition from two sticks to four sticks, and
a change from DDR400 automatically to DDR333. And that pattern
matches AMD S939 processors.

Paul

Good catch, Paul. I had nearly forgotten about this little detail about
AMD processors at that time.

 

[Docster]

I recall something call some characteristic in memory called "spd" which has
something to do with speed detection.

I deduced it all, and await confirmation of the missing details.

Only AMD does this.

My Intel chipset DDR400 motherboard has no such penalty, and
that's how I know the processor is AMD. I can stick two or four
matched sticks in the 875P based motherboard, and it always runs
at DDR400. There was a claim that chipset runs Command Rate 2
under all conditions, but without an exposed BIOS setting,
it's hard to know that for sure. Lots of stuff about chipsets,
can only be determined with an oscilloscope (due to the limitations
of what is stated in data sheets).

The OP stated a transition from two sticks to four sticks, and
a change from DDR400 automatically to DDR333. And that pattern
matches AMD S939 processors.

Paul

Good catch, Paul. I had nearly forgotten about this little detail about
AMD processors at that time.

 

[Paul]

I recall something call some characteristic in memory called "spd" which has
something to do with speed detection.

SPD stands for serial presence detect. It's a chip that holds the
Plug and Play information for the DIMM, including memory size and
memory timing information. It sits on a serial bus (SMBUS) and
is read out by the BIOS when the computer starts. The serial bus
runs at a very low speed, like around 10KHz (whereas, more
normally, it would run at 400KHz).

http://upload.wikimedia.org/wikipedia/commons/a/a7/SPD_SDRAM.jpg

( http://en.wikipedia.org/wiki/Serial_presence_detect )

But the choice of DIMM memory operating speed, is up to the BIOS.
The SPD can give info on timing settings for operating at DDR333 or DDR400,
but the BIOS makes the decision as to what speed to run things at.
And the "down clocking" on the S939, is a policy recommended by AMD,
rather than being dreamed up by the manufacturer of the motherboard.

On one AMD motherboard from that era, the user manual even contains
a copy of the timing table from an AMD document, as if to say
"it isn't our fault it works this way" I presume they did that,
so they'd get fewer whiny phone calls at tech support.

Paul