Slightly OT: SODIMM question.

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I just recently advised a friend on a laptop purchase. Nothing amazing, just
something to replace his PII 300 that would do what he wanted at a price he
was willing to spend.

I settled on a Compaq Presario V5234 (A model I think is peculiar to
NZ/Australia). Celeron M @ 1.46GHz on a 133MHz (533) FSB with 1MB L2, 60GB,
5,400rpm HDD, 15.4" wdiescreen, DVD writer, wireless (not that he's going to
use that).

Anyway, the funny thing is, it came with only 256MB RAM (as these things do)
so I wanted to throw another 512MB SODIMM in there. I looked it up on
Compaq's site and it says it needs DDR2 667. That doesn't sound right... I
got the salesman to remove the SODIMM in there and look at it, he tells me
it's 667 DDR2. They don't have any in stock. I'm adamant that 667 isn't
needed (and am frankly surprised that such a relatively old CPU is running
DDR2). He does however have DDR2 553 in stock so I get a stick of that an
throw it in and it's all good.

So, I'm assuming that Compaq did what OEMs often do and fit whatever RAM
they've managed to buy at the best price and have the biggest supply of.
Also, when I finally managed to find a Compaq page that has the specs for
that model listed it has two machines with the same model number, one the
Celeron M/256MB RAM/60GB HDD and the other a Core Duo/1GB RAM/120GB HDD

They both use DDR2 667 RAM. Odd no? Especially as, if you look up on
Compaq's site what RAM to use to upgrade the Celeron M (V5234) it says DDR2
667 when the machine patently doesn't need that RAM.

I'm unfamiliar with SODIMMs and DDR2 so this question may be silly. From
what I can tell, both DDR and DDR2 SODIMMs are 200-pin. Do they have notches
in different places or will they both physically fit the same slot? Or, will
DDR2 fit (and work) in a DDR slot but not the other way around, in the way
that AGP cards were backwards compatible slot-wise.

The point of all these questions, the thing I'm wondering about, is; Would
this Celeron M laptop, although fitted with DDR2, work with plain DDR? I
notice that DDR2 is cheaper than DDR in most places and wondered if it was
installed in this laptop as a cost-saving rather than because it needed

Thanks for sticking with me if you've read this far, and thanks for any
answers to my questions.


Re: Slightly OT: SODIMM question.

~misfit~ wrote:
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1) DDR and DDR2 are NOT interchangable.

2) You put slower memory in than spec'd, You did research, and then
discounted it. AND The fellow at the PC shop TOLD you is was 667 inside
the machine, and you overrode him, too. IF the 533 RAM turns out to be
unstable in your system, i would not expect the PC shop to take it

You might lucky. But don't expect a refund.

Re: Slightly OT: SODIMM question. wrote:
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Hi Paul, thanks for your not-very-helpful post.

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Why? Are the slots physically different? This is a statement, I asked for
specifics, relating to SODIMMs.

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My research (and the specs sheet with the laptop) both said that the Celeron
M that was in the machine was on a 533FSB.

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I know the guy quite well, having spent a lof of money there. He was
interested as to why 667 was specced on a machine that had a 533 FSB and is
curious to know how it goes. He asked me to let him know, hence this post to
try to gather more info. (BTW, the laptop is still running the CPU at the
correct speed and it runs Memtest86+ and Prime95 just fine

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Well I'm pleased that I'm not dealing with you. The guy at the shop told me
to keep the packaging and that I could return the RAM (and/or laptop)
anytime in the next 14 days for a full, no-questions-asked refund. One year
if either proves to be defective.

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I is lucky. I will get a refund if I need it. The (fairly knowledgeable) guy
in the shop is as curious as I am as to why a 533 MHz FSB 1.4GHz Celeron M
would need 667MHz RAM. (We are under the impression that Compaq are just
being lazy and speccing the two machines alike rather than have two seperate
web-pages) Especially as they're selling a few of them, but can't get 667
SODIMMs for a wee while, it's back-ordered, and most people who would buy
one don't as the shop offers a free RAM fitting at time of purchase option
and who the hell is going to try to run Win XP, Nortons (pre-loaded) etc. on

Thank you for your totally information-free post. I've never seen so much
written by someone who knows so little. Why even bother to reply?

Re: Slightly OT: SODIMM question.

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DDR and DDR2 have the notches on 200 pin SODIMMs in different places and
have different voltage requirements, 2.5 vs. 1.8. I also noted that the link
you provided clearly says the Celeron version is 533 MHz Buss.

Re: Slightly OT: SODIMM question.

pen wrote:


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Thanks pen. I've not had much to do with laptops before so didn't know about
the notches thing. Frankly I'm surprised that a 1.4GHz Celeron uses DDR2.

Yes, the Celeron version is 533 but comes factory-fitted with 667 and, when
you look up what RAM to get, or order some from Compaq, they claim 667 is
needed. I refused to believe that and fitted 553 (as I would have had a long
wait for the store to get 667 in and I prefer to deal with one store for the
same machine. The machine was needed that day, mission-critical) and it all
looks good so far. I just wanted some other input as the laptop wasn't for
me, it's for a friend who knows nothing about computers but came to me and
asked me to find him the best value-for-money replacement for his PII 300
that had just died. He didn't really care about CPU power, as long as it did
what his PII 300 (with 192MB RAM, running XP) did.

Needless to say he's over the moon with his new laptop with 768MB RAM. I
stuck his old HDD on the end of a USB - IDE adapter and loaded all his data
onto his new machine and he's very happy.

Thanks a lot for your insight, much appreciated.

Re: Slightly OT: SODIMM question.

~misfit~ wrote:
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IME buying desktop ram, the 667 chips were about 2 more than the 533,
at a guess I would say that you are right about compaq putting higher
spec memory in, so if the sodimm ddr2 533 is cheaper I can't see that
not working.

Re: Slightly OT: SODIMM question.

MadFox wrote:
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Thanks MadFox. It wasn't so much a case of the 533 being cheaper, in fact it
was $5 dearer. The problem was the store didn't have 667 in stock and
couldn't get any until next week at the earliest. (Maybe, as Kony says, it's
being bought up in anticipation of a christmas run on product, this store is
having major trouble getting it). The guy I was getting the laptop for
couldn't wait for the 667 to be delivered, he needed it that day. It seems
perfectly fine with the 533, I *do* think that over-specced RAM was fitted,
probably for simplicity's sake at the manufacturing plant.


Re: Slightly OT: SODIMM question.

On Mon, 11 Sep 2006 18:05:30 +1200, "~misfit~"

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Remember that P4 has quad pumped FSB, that in some cases
having  higher memory bus speed can offset the penalty from
asychronous FSB speed.  Further, if it has integrated video
(or the base chipset does, even if it happened to have a
video card installed too) they would tend to install the
highest speed memory that the chipset supports in async

I'd wonder though, why not get the fastest memory you can so
it has the longest supported life?  A laptop might break,
but things like the memory may be reusable.  Unfortunately
sometimes the higher speed has a higher latency too, it
seems more expensive at the moment, supposedly OEMs are
buying up surplus DDR2 for the Christmas season right now
and prices may be higher till late in the year or even early

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I'd imagine this is true, and/or, they are fitting this
memory in all these notebooks to keep as many parts as
possible the same, but same platform also has the Pentium M
plugged in instead in upper models.

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Remember that OEMs don't like to troubleshoot and really
won't troubleshoot 3rd party parts.  They will spec that you
should add exactly what was already in the system, not
necessarily any and everything that will work with it.  They
may also copy-n-paste specs from one upper model to the rest
of the family, or at least as much as possible and overlook
some parts... or the person writing the page might not have
even known.

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You might benchmark it with only one, then the other module
installed, particularly things like very light (old) games
to see if the framerates are the same, and/or other
synthetic benches like the quick one on Memtest86+ or Sisoft

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Notches differ.

No, they can't be mixed or put into wrong slot for the other

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No, it uses an Intel centric chipset and those all shifted
to DDR2, because someday the memory tech will catch up and
as a result DDR2 will be faster - Intel just rushes things
into the market because they can, and because general public
may presume DDR2 is automatically "+1" better than DDR1.

Re: Slightly OT: SODIMM question.

kony wrote:
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Thanks for the response Dave. I got the 533 as that was all that was in
stock and the guy I was buying the laptop for needed it pronto, that

I might run Memtest with just the 256 in and then both and see if the memory
is reported as different speeds (or whether both times it runs at 533). I
can't be bothered booting into windows and installing and running
benchmarking software with only 256MB RAM. It's as slow as a wet week like
that. Also, it's a business laptop, the owner is more than happy with it
as-is, I don't want to go installing a whole bunch of stuff that doesn't
need to be there.

Cheers mate,

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