RAM difference

  • Thread starter Thread starter Daave
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Daave

I have an HP Pavilion ze5700 notebook with a whopping 256 MB RAM (and
onboard video)!

Yes, HP for some reason thought this was enough RAM to run Windows XP!

I'd like to add more RAM. I see no reason why I can't add 512 MB.

However, I'm a bit confused. Please compare these two modules:

http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=D252D384A5CA7304

and

http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=1FEC39EBA5CA7304


Other than the $15 price difference, it's hard to see what else is
different. One is for a Pavilion and the other is for a Presario. But
the only other difference I see is that the Presario one says "64Meg X
64." What does that mean? Is there a real difference?
 
Daave said:
I have an HP Pavilion ze5700 notebook with a whopping 256 MB RAM (and
onboard video)!

Yes, HP for some reason thought this was enough RAM to run Windows XP!

I'd like to add more RAM. I see no reason why I can't add 512 MB.

However, I'm a bit confused. Please compare these two modules:

http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=D252D384A5CA7304

and

http://www.crucial.com/store/mpartspecs.aspx?mtbpoid=1FEC39EBA5CA7304


Other than the $15 price difference, it's hard to see what else is
different. One is for a Pavilion and the other is for a Presario. But
the only other difference I see is that the Presario one says "64Meg X
64." What does that mean? Is there a real difference?
Click to expand...

The difference between the products, is these two lines.

"Each memory slot can hold DDR PC2700 with a maximum of 512MB per slot"

"Each memory slot can hold DDR PC2700 with a maximum of 1GB per slot"

One computer supports a different chip density than the other.

*******

The module manufacturers try not to give away density information.
If they spec a custom module for a computer, there is never a
datasheet. If they sell "generic" modules, where the customer
takes the risk, they're willing to give datasheets for those.
But then, you can't be sure they'll work (or whether they'll be
"half-detected).

http://www.valueram.com/datasheets/default.asp#DDR SODIMMs

As for "dimensional" descriptors, 64M x 64 doesn't tell me anything
(other than you're getting a 512MB module). If you told me the
composition was "sixteen 32M x 8-bit chips), then you'd be
telling me something. Memory comes in 64 bit wide arrays, so in
that specification, I'd need eight 32Mx8 chips laid side by
side, to make a 64 bit wide array. I could put an array
on both sides of the module, making a dual rank unbuffered
SODIMM. So (16) 32Mx8 is a fairly full description, while
64M x 64 is meaningless (because they likely already told
you the module was 512MB). I can tell the (16) 32Mx8 is
a dual rank module, which might be important to me
(bus loading).

http://www.valueram.com/datasheets/KVR333X64SC25_512.pdf

Paul
 
The difference between the products, is these two lines.

    "Each memory slot can hold DDR PC2700 with a maximum of 512MB perslot"

    "Each memory slot can hold DDR PC2700 with a maximum of 1GB per slot"

One computer supports a different chip density than the other.

*******

The module manufacturers try not to give away density information.
If they spec a custom module for a computer, there is never a
datasheet. If they sell "generic" modules, where the customer
takes the risk, they're willing to give datasheets for those.
But then, you can't be sure they'll work (or whether they'll be
"half-detected).

http://www.valueram.com/datasheets/default.asp#DDR SODIMMs

As for "dimensional" descriptors, 64M x 64 doesn't tell me anything
(other than you're getting a 512MB module). If you told me the
composition was "sixteen 32M x 8-bit chips), then you'd be
telling me something. Memory comes in 64 bit wide arrays, so in
that specification, I'd need eight 32Mx8 chips laid side by
side, to make a 64 bit wide array. I could put an array
on both sides of the module, making a dual rank unbuffered
SODIMM. So (16) 32Mx8 is a fairly full description, while
64M x 64 is meaningless (because they likely already told
you the module was 512MB). I can tell the (16) 32Mx8 is
a dual rank module, which might be important to me
(bus loading).

http://www.valueram.com/datasheets/KVR333X64SC25_512.pdf

    Paul- Hide quoted text -

- Show quoted text -
Click to expand...

Thanks, Paul.

I just finished a chat session with someone from Crucial. This is what
she said:

"The Pavilion ze5700 Series must have 16 chip, low density installed."

So, I guess I'll get the more expensive kind.

But I wonder what would happen (hypothetically) if I installed the
other (higher density) module instead.
 
Daave said:
Thanks, Paul.

I just finished a chat session with someone from Crucial. This is what
she said:

"The Pavilion ze5700 Series must have 16 chip, low density installed."

So, I guess I'll get the more expensive kind.

But I wonder what would happen (hypothetically) if I installed the
other (higher density) module instead.
Click to expand...

"Half-detected" is what would happen. The computer would run,
but the 512MB module you added, would add only 256MB to the system.
The rest of the memory would be inaccessible, because an address
signal line is effectively missing from the Northbridge.

Paul
 
"Half-detected" is what would happen. The computer would run,
but the 512MB module you added, would add only 256MB to the system.
The rest of the memory would be inaccessible, because an address
signal line is effectively missing from the Northbridge.

    Paul- Hide quoted text -

- Show quoted text -
Click to expand...

Thanks, Paul.
 
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