RAM compatability

[t@k]

I have a Toshiba Satellite Pro A100 with SAMSUNG PC2 4200 DDR2 444
SODIMM 1X 512MB RAM with a spare slot.

Should I be able to upgrade to SAMSUNG PC2 PC5300/5400 DDR2 667 SODIMM
2X 1GB?

Thanks.

 

[Paul]

I have a Toshiba Satellite Pro A100 with SAMSUNG PC2 4200 DDR2 444
SODIMM 1X 512MB RAM with a spare slot.

Should I be able to upgrade to SAMSUNG PC2 PC5300/5400 DDR2 667 SODIMM
2X 1GB?

Thanks.

http://www.crucial.com/store/listparts.aspx?model=Satellite+Pro+A100+Series

"Q: What memory goes into my computer, and will a faster speed
be backward-compatible?

A: DDRII memory with support for DDR2 PC2-4200 speeds.
Because DDR2 memory is backward-compatible, you can safely upgrade
your system with any of the guaranteed-compatible DDR2 speeds listed
below."

What that means, is the computer will run the memory at PC2-4200 speed.
All of the Crucial listed memory is PC2-4200.

You can see more notes here:

http://www.ec.kingston.com/ecom/configurator_new/modelsinfo.asp?SysID=35845

"These systems are configurable from Toshiba and, depending on region,
may ship with either DDR2-533 or DDR2-667. These can be mixed, however,
when mixed they will default to DDR2-533."

Kingston has a number of entries for the A100, which is where I found that one.

http://www.ec.kingston.com/ecom/con...ne=Satellite+Pro&distributor=0&submit1=Search

The memory controller is within the 945GM Northbridge. Section 10.2
on PDF page 337, describes the memory capability. Since the chipset
can handle higher density chips, I don't expect a problem with
using 1GB sized modules. (This datasheet describes more than one
chip, so sometimes there are multiple sections discussing the same
topic.)

http://download.intel.com/design/mobile/datashts/30921904.pdf

HTH,
Paul

 

[t@k]

Paul said...

The memory controller is within the 945GM Northbridge. Section 10.2
on PDF page 337, describes the memory capability. Since the chipset
can handle higher density chips, I don't expect a problem with
using 1GB sized modules. (This datasheet describes more than one
chip, so sometimes there are multiple sections discussing the same
topic.)

Thanks for your reply.

I have just purchased the latter from a reputable seller on eBay. They
don't work as a pair or individually. I did initially email the seller
regarding compatibility but got no reply.

There is one noticeable difference between them and the original i.e.
the original stick needs quite firm pressure to seat it in the slot
before clipping it down but the new ones practically fall in, suggesting
that the edge connectors could be significantly thinner.

Do you think I have cause for complaint?

 

[Paul]

Paul said...


Thanks for your reply.

I have just purchased the latter from a reputable seller on eBay. They
don't work as a pair or individually. I did initially email the seller
regarding compatibility but got no reply.

There is one noticeable difference between them and the original i.e.
the original stick needs quite firm pressure to seat it in the slot
before clipping it down but the new ones practically fall in, suggesting
that the edge connectors could be significantly thinner.

Do you think I have cause for complaint?

Do the modules have part numbers on them ?

Did you verify the modules are DDR2, and the right spec ?

"Practically fall in" does not sound good.

Do they have the right number of contacts, same as the original module ?

I hope they haven't damaged the notebook...

Paul

 

[t@k]

Paul said...

Do the modules have part numbers on them ?

Did you verify the modules are DDR2, and the right spec ?

"Practically fall in" does not sound good.

Do they have the right number of contacts, same as the original module ?

I hope they haven't damaged the notebook...

Thankfully no damage has been done.

Pics of original and replacements...
http://picasaweb.google.co.uk/fade2gray.uk/DDR2SODIMMRAM

Extract from sellers reply to my complaint...

Regarding compatibility, if we did not reply to you does not mean that
it is compatible.

Regarding the modules, as far as we understand, it is not compatible,
You need the 533 and not the 667. Usually the 667 are backward
compatible, but it does not seem to be the case. Also, if both dont
work, we think it is incompatibility.

What we can do is replace them for 2 of the 533 1GB modules.

Personally I think they're both duff - I might take them down PCWorld
and ask if they could heck them out for me.

Just hope the seller will cover postage and re-imbure me the difference.

 

[Paul]

Paul said...


Thankfully no damage has been done.

Pics of original and replacements...
http://picasaweb.google.co.uk/fade2gray.uk/DDR2SODIMMRAM

Extract from sellers reply to my complaint...



Personally I think they're both duff - I might take them down PCWorld
and ask if they could heck them out for me.

Just hope the seller will cover postage and re-imbure me the difference.

The Ebay module looks like (16) 64Mx8 chips for 1GB total. These look to be
the chips used.
http://www.samsung.com/products/sem...M/Component/512Mbit/K4T51083QC/K4T51083QC.htm

The original module is here with (8) 32Mx16 chips for 512MB total.
http://www.samsung.com/products/sem...M/Module/SODIMM/M470T6554CZ3/M470T6554CZ3.htm

Here is a picture of a 945GM based computing device, and it is
pictured with both a 2Rx16 (two ranks, of x16 bit devices) 512MB
SODIMM (that is the one you've got) and a 2Rx8 (two ranks, of x8
bit devices). So at least this gives the impression that a 16 chip
SODIMM would work.

http://www.radisys.com/products/datasheets/Procelerant CE 945GM.pdf

Trying another approach, I searched for memory for an AOpen
motherboard that also uses a 945GM and a Pentium M processor.
This is the Kingston product returned for it.

http://www.valueram.com/datasheets/KVR533D2S4_1G.pdf

So I don't think it is the module construction that is
at fault, unless the socket is just not making good contact
with the module.

Paul

 

[t@k]

The guy down PCWorld wouldn't test the modules due to company policy
(understandable), but he also would have expected the 667's to be
compatible with my notebook.

Thanks for all the links...

http://www.valueram.com/datasheets/KVR533D2S4_1G.pdf

A little disappointing that this datasheet gave all the board's
dimensions except for the thickness of the edge connector.

Would it be detrimental to use an engineer's micrometer on the edge
connector of the modules in order to make a comparison?

 

[Paul]

The guy down PCWorld wouldn't test the modules due to company policy
(understandable), but he also would have expected the 667's to be
compatible with my notebook.

Thanks for all the links...
A little disappointing that this datasheet gave all the board's
dimensions except for the thickness of the edge connector.

Would it be detrimental to use an engineer's micrometer on the edge
connector of the modules in order to make a comparison?

If you are at the same electrostatic potential as the module,
and you don't scrape up the gold, it shouldn't hurt. Finger
prints tend to leave a mark, so just make contact via the
micrometer or caliper, and not with your fingers.

The thickness spec, should either be found in a spec for an
SODIMM socket, or by looking in a JEDEC spec.

Page 2 here shows 1.0 mm +/- 0.1mm for the thickness. DDR2 is the
"AB" variant shown in this document, at least that is what I get
by comparing the Kingston outline drawing, to this one.

http://www.jedec.org/download/search/MO-224E.pdf

Paul