Laptop memory question

[The Seabat]

I have an old Dell D600 laptop and was toying with the idea of
upgrading the memory in it. Currently has 256mb strip in it. Was
thinking of dropping a 1gb strip into it 'cause I can get one for
around $20. The problem is the voltage. All the strips I've looked at
say the voltage is 2.5v to around 2.8v. The Dell is spec'd at 3.3v!
Will these strips work without burning up? Inquiring minds would like
to know! Thank you.

 

[TM]

"The Seabat" wrote in message
I have an old Dell D600 laptop and was toying with the idea of
upgrading the memory in it. Currently has 256mb strip in it. Was
thinking of dropping a 1gb strip into it 'cause I can get one for
around $20. The problem is the voltage. All the strips I've looked at
say the voltage is 2.5v to around 2.8v. The Dell is spec'd at 3.3v!
Will these strips work without burning up? Inquiring minds would like
to know! Thank you.

--
The Seabat

Acc. to the specs I've seen -- even from the Dell website -- the D600
memory modules are 2.5V.
You should be good to go.

 

[Nobody > (Revisited)]

I have an old Dell D600 laptop and was toying with the idea of
upgrading the memory in it. Currently has 256mb strip in it. Was
thinking of dropping a 1gb strip into it 'cause I can get one for
around $20. The problem is the voltage. All the strips I've looked at
say the voltage is 2.5v to around 2.8v. The Dell is spec'd at 3.3v!
Will these strips work without burning up? Inquiring minds would like
to know! Thank you.

I think you have found the wrong specs.

I *severely* doubt that Dell would have used non-standard DDR SODIMMs in
a mainstream product like yours. 2.5v is the design spec.

http://www.crucial.com/store/listparts.aspx?model=Latitude D600&pl=Latitude&cat=

http://snipurl.com/delld600memcrucial

--
"Shit this is it, all the pieces do fit.
We're like that crazy old man jumping
out of the alleyway with a baseball bat,
saying, "Remember me motherfucker?"
Jim “Dandy” Mangrum

 

[Paul]

I have an old Dell D600 laptop and was toying with the idea of
upgrading the memory in it. Currently has 256mb strip in it. Was
thinking of dropping a 1gb strip into it 'cause I can get one for
around $20. The problem is the voltage. All the strips I've looked at
say the voltage is 2.5v to around 2.8v. The Dell is spec'd at 3.3v!
Will these strips work without burning up? Inquiring minds would like
to know! Thank you.

Each memory type, has its own operating voltage. When you see products
with radically different voltages (i.e. not enthusiast products, but
just industry standard products), then you're mixing incompatible memories.

http://en.wikipedia.org/wiki/SDRAM

(See "Feature Map" section)

SDRAM Vcc=3.3V Typical name PC133
DDR1 Vcc=2.5V Typical name DDR400 or PC3200
DDR2 Vcc=1.8V Typical name DDR2-800 or PC2-6400
DDR3 Vcc=1.5V Typical name DDR3-1333 or PC3-10666

Enthusiast memory uses additional voltage to achieve higher (above industry
standard) speeds. The 2.5V RAM might be run at 2.75V. The 1.8V ram might be
run at 2.1V. The 1.5V RAM might be bumped as well. There was one least one case,
where it was possible for a RAM to be run at so high a voltage, as to
enter the domain of a previous RAM product - Winbond DDR at 2.5V, could be
raised all the way to 3.3V without immediately burning out. That's an exception.
Most of the time, the voltage values used by enthusiast products, don't cross
over into the next domain.

Each DIMM generation, has a different form factor. No two modules holding the
above memory chips, should fit in the same socket. The socket includes a "key"
which prevents mating, if the voltage is not compatible. As well as pin
count differences. While these are desktop pinouts, the same concepts
will apply to laptops. JEDEC will be careful to make enough differences,
so the wrong things won't plug in.

SDRAM 168 pins
DDR1 184 pins
DDR2 240 pins
DDR3 240 pins

http://novaonline.nvcc.edu/eli/itn107mb/f-ram.htm

http://novaonline.nvcc.edu/eli/itn107mb/ddr3.jpg

"While DDR3 uses the same number of connector pins as the 240 pin DDR2 RAM,
the notch is in a different position and the two systems are not
interchangeable."

A laptop should be using similar features (different size, pincount,
notch/key) to prevent illegal combinations.

*******

If I go to Crucial and search for Dell D600 (Latitude) using the search box...

http://www.crucial.com/search/searchresults.aspx?keywords=dell d600

PC2700 DDR 2.5V ...

So you're looking for DDR RAM ("DDR1"), rather than say 3.3V SDRAM.

The list on the Kingston site is even shorter.

http://www.ec.kingston.com/ecom/configurator_new/modelsinfo.asp?SysID=14354

Standard Memory: 128 MB (Removable)
Maximum Memory: 2 GB
Expansion: 2 Sockets
CPU & ChipSet: Intel Pentium M with Intel 855PM

This system is configurable and may ship with a different amount of
standard memory. Systems may also ship with either DDR266 or DDR333.
When mixed, the memory will only run at DDR266.

(And "DDR266" or "DDR333" are DDR at 2.5V)

There is an interface difference, between 3.3V SDRAM and 2.5V DDR. The
2.5V DDR transfers two data words per clock cycle. The SDRAM transfers
one data word per clock cycle. And that's where the "double data rate" came
from - the data transfer phase uses both edges of the clock signal. And
that would be an excellent reason, why an SDRAM module would not work
in a DDR product - they're different protocols. So it's not only voltage
and pin count that are different, but the actual electrical signals
follow different rules.

*******

Where did you see "The Dell is spec'd at 3.3v!" ???

Paul

 

[The Seabat]

This is what I got from the manual for the D600 here:

http://www.imagebam.com/image/975533150600471

I thought maybe I read it wrong, but doesn't it say 3.3 volts??

 

[Nobody > (Revisited)]

This is what I got from the manual for the D600 here:

http://www.imagebam.com/image/975533150600471

I thought maybe I read it wrong, but doesn't it say 3.3 volts??

It does, but I suspect a typo ... Even more after doing some detailed
searches. IMHO, the manual is FUBAR here. There's too much evidence
elswhere.

(Just an FYI... I have a problem calling a SODIMM a"stick", "slab" fits
it better. It's not my invention, I picked it up from the IT folks at my
old job.)

Just to check, I went to Kingston's site as well.
Maybe it's me, but I *cannot* find the voltage on their 1 gig slabs #
KTD-INSP5150/1G.

"backsearching" KTD-INSP5150/1G.... Newegg's got it w/specs!
"Voltage 2.5V"
http://www.newegg.com/Product/Product.aspx?Item=N82E16820141330

I went to Dell's support site and got p/n SNP1Y255C/1G, but no specs.

Again, "backsearching" SNP1Y255C/1G
http://www.parts-quick.com/snp1y255c-1g.html
"Voltage 2.5V"

(I did about 5 other sites on both p/ns and if there was a spec it was
always 2.5v)

I'm 99.999% certain ("four 9s") the manual is in error (even checked out
the D660 manual at dell.com, still says 3.3v). This isn't the first
owner's manual that's wrong, seen it all too often! (I've found at
least 7 'wrongos' in the printed manual that came with my Tosh NB305
netbook, 4 were corrected in the online version).

The backsearching is always a good idea if something doesn't look right.
I've done this for 40+ years on replacement electronic parts, even back
to the paper "substitution manuals". My bench bookshelf was about 4 feet
long with two levels, mostly parts manuals. That has saved my bacon and
reduced the smoke clouds *many* times.

If you can get a 1 gig slab for $20, go for it. The only thing I would
do (as a precaution) is to take the quarter-gig plank out first to avoid
collateral damage for the "smoke test".

I've messed up in the past on memory voltage when using used unknown
memory and have overvolted a few slabs and sticks, so I speak from
experience.

The difference between 2.5v and 3.3v is enough that if I'm wrong, the
slab/stick will screw up within about 20-60 seconds, and it will fail
booting and/or loading the OS. If so, *KILL THE POWER IMMEDIATELY*! The
RAM may die, but the motherboard has about an 85+% probability of living
thru this if caught quick enough.

If all's well (NO SMOKE! and it boots to OS), load a self-booting memory
test like Memtest86+ (http://memtest86.com/) and let it run overnite
with all power-save options turned off in BIOS.

If that flies, put the quarter-gigger slab back in. You may have to
rearrange the slot/size order, no biggie. I'd still repeat the memtest
tho, just for grins. There's still a noticeable (but small) advantage to
having 1¼ gigs vs 1.0 gigs of RAM but I'd get another 1 gig slab of the
same as the one you started out with.

I went thru the same (except for the voltage ambiguity issue) on a
similar Gateway laptop on XP. The results were amazing, but then I'd
never seen XP-SP2 or 3 running on just a quarter-gig of RAM before. Even
the wurk IT department went thru all the XP laptops and boosted them to
1 or 2 gigs before rolling out the in-house SP2 service pack.

Before, almost all task switches took as much as a minute. Afterwards it
was down to absolute worst 10 seconds. Even before the RAM boost, I'd
already done the "lean and mean clean" to speed up the machine. It had
an old and dead version of MacAffe's security suite on it. Since it was
useless, I replaced MacAFart with Avast/MBAM/Zonealarm , all "free"
versions to get it to THAT point. Before that, you might as well go brew
coffee while you waited for an "HTML and big pics" email to open.

Hope this helps.....






--
"Shit this is it, all the pieces do fit.
We're like that crazy old man jumping
out of the alleyway with a baseball bat,
saying, "Remember me motherfucker?"
Jim “Dandy” Mangrum

 

[Paul]

This is what I got from the manual for the D600 here:

http://www.imagebam.com/image/975533150600471

I thought maybe I read it wrong, but doesn't it say 3.3 volts??

Yeah, it's wrong

DDR is 2.5V. The JEDEC committee specified 2.6V for DDR400 chips,
which was done by some of the committee members to guarantee the
chips yielded at the factory. It turned out, that 2.5V would have
been enough anyway. I don't recollect anyone having trouble making
DDR400. There was no whining at the time.

You can use the info on sites like Crucial or Kingston, as a source
of confirmation.

Paul

 

[Loren Pechtel]

(Just an FYI... I have a problem calling a SODIMM a"stick", "slab" fits
it better. It's not my invention, I picked it up from the IT folks at my
old job.)

Memory comes in sticks. The mere fact that the SODIMM is more
slab-shaped doesn't change this.

 

[Nobody > (Revisited)]

Memory comes in sticks. The mere fact that the SODIMM is more
slab-shaped doesn't change this.

"Stick" is still semiprofessional slang, every trade has slang names for
"stuff". "Module" is the real term, but it's just too.. formal
sounding?. It's just that "stick" stuck well.

If you want to quibble, when memory first started being put on removable
modules instead of socketed ICs (SIPPs, SIMMs etc) they were also called
"strips"? I remember one vendor calling them "memory miniboards".



--
"Shit this is it, all the pieces do fit.
We're like that crazy old man jumping
out of the alleyway with a baseball bat,
saying, "Remember me motherfucker?"
Jim “Dandy” Mangrum

 

[Loren Pechtel]

"Stick" is still semiprofessional slang, every trade has slang names for
"stuff". "Module" is the real term, but it's just too.. formal
sounding?. It's just that "stick" stuck well.

If you want to quibble, when memory first started being put on removable
modules instead of socketed ICs (SIPPs, SIMMs etc) they were also called
"strips"? I remember one vendor calling them "memory miniboards".

Sure, it's slang but it's become the term in common usage. The
non-standard shape of a SODIMM wasn't enough to change the term.