Questions about DDR RAM

I'm planning to add some memory to a PC. The motherboard supports "DDR up
to 333 MHz (enhanced) memory bus."

333 MHz (PC2700) or slower DDR SDRAM isn't easy to find on today's market,
and when you do find it, it's considerably more expensive than the DDR
which runs at 400 MHz (PC3200). What would happen if I bought 400 MHz DDR
RAM and installed it in a motherboard which only supports speeds up to 333
MHz (PC2700)? Would it work? If it did work, would it work as well as the
slower PC2700 RAM?

I've gotten conflicting answers to this question. Two computer stores told
me that it wouldn't work. Another store and a book I consulted said it
would.

I'd also like some opinions on which brand of RAM I should get. Kingston
and Samsung are ubiquitous where I live, so the choice comes down to one
of those. Both brands are about the same price, with the Samsung being
marginally cheaper.

Finally, would a 128 MB stick of 266 MHz DDR RAM be able to run in the
same computer as, say, a 512 MB stick of 400 MHz DDR RAM? If so, would
using both at the same time degrade the performance of the faster RAM?

--
(Note: I'm using a bogus reply-to address to avoid spam, so please don't
reply by email.)

Igor wrote:
I'm planning to add some memory to a PC. The motherboard supports "DDR
up to 333 MHz (enhanced) memory bus."

333 MHz (PC2700) or slower DDR SDRAM isn't easy to find on today's
market, and when you do find it, it's considerably more expensive than
the DDR which runs at 400 MHz (PC3200). What would happen if I bought
400 MHz DDR RAM and installed it in a motherboard which only supports
speeds up to 333 MHz (PC2700)? Would it work? If it did work, would it
work as well as the slower PC2700 RAM?

I've gotten conflicting answers to this question. Two computer stores
told me that it wouldn't work. Another store and a book I consulted said
it would.

I'd also like some opinions on which brand of RAM I should get. Kingston
and Samsung are ubiquitous where I live, so the choice comes down to one
of those. Both brands are about the same price, with the Samsung being
marginally cheaper.

Finally, would a 128 MB stick of 266 MHz DDR RAM be able to run in the
same computer as, say, a 512 MB stick of 400 MHz DDR RAM? If so, would
using both at the same time degrade the performance of the faster RAM?


If you tell us the motherboard make and model, we give better advice.
If the machine is Dell or HP, tell us the model number etc.

Faster DDR is compatible with slower speed applications.

Whether mixing RAM makes sense, really depends on what speed the motherboard
and its current configuration, would support. If your processor is limiting
the speeds that the Northbridge can run the memory, then maybe removing the
128MB stick would make no difference.

Details count. Motherboard and processor information would help. You can
also get some hints from looking at both:

http://www.crucial.com ("Crucial memory advisor")
http://www.kingston.com ("Memory search")

HTH,
Paul

On Tue, 02 Oct 2007 17:31:38 -0400, Igor
wrote:

I'm planning to add some memory to a PC. The motherboard supports "DDR up
to 333 MHz (enhanced) memory bus."

333 MHz (PC2700) or slower DDR SDRAM isn't easy to find on today's market,
and when you do find it, it's considerably more expensive than the DDR
which runs at 400 MHz (PC3200). What would happen if I bought 400 MHz DDR
RAM and installed it in a motherboard which only supports speeds up to 333
MHz (PC2700)? Would it work? If it did work, would it work as well as the
slower PC2700 RAM?

Yes it'll work and do so as well/fast as PC2700, providing
it has timings spec'd at least as (Low) fast as the PC2700
module had. This is not a large difference in performance
though so a random suggestion would be to get a CAS2.5 @ 2.5
or 2.6V spec'd part.



I've gotten conflicting answers to this question. Two computer stores told
me that it wouldn't work. Another store and a book I consulted said it
would.

Avoid those two computer stores from now on when seeking
advice, or at least the particular techs you spoke with as
PC3200 is always backwards compatible. It's the same memory
only the maxium speed the PC3200 is guaranteed to be able to
run stabily is higher, and the prom on the module is
programmed with timings to validate this if/when a
motherboard checks to see what the memory can do.



I'd also like some opinions on which brand of RAM I should get. Kingston
and Samsung are ubiquitous where I live, so the choice comes down to one
of those. Both brands are about the same price, with the Samsung being
marginally cheaper.

Which country do you reside in? Often buying online is
cheaper unless there's a particularly good sale or rebate
ongoing. Kingston's valueram tends to be lower spec, many
other name brand modules are better or cheaper for the same
specifications.



Finally, would a 128 MB stick of 266 MHz DDR RAM be able to run in the
same computer as, say, a 512 MB stick of 400 MHz DDR RAM? If so, would
using both at the same time degrade the performance of the faster RAM?

The two could run in single channel mode, which would be the
mode it was in currently. Some motherboard chipsets can run
dual channel mode for a performance increase (which varies
from very little to a fair amount) and some of these require
two of same size and compatible timings, modules. Some only
require two modules with compatible timings but need not be
the same size (would then support dual channel mode only up
to the amount of memory of the smallest module total on one
channel, times 2). nForce 2 is an example of such a chipset
that can do this, though unless using integrated video the
performance gain from dual channel mode is minimal.

Igor wrote:

I'm planning to add some memory to a PC. The motherboard supports
"DDR up to 333 MHz (enhanced) memory bus."

333 MHz (PC2700) or slower DDR SDRAM isn't easy to find on today's
market, and when you do find it, it's considerably more expensive
than the DDR which runs at 400 MHz (PC3200). What would happen if
I bought 400 MHz DDR RAM and installed it in a motherboard which
only supports speeds up to 333 MHz (PC2700)? Would it work? If it
did work, would it work as well as the slower PC2700 RAM?

I've gotten conflicting answers to this question. Two computer
stores told me that it wouldn't work. Another store and a book I
consulted said it would.

The faster stuff is just fine. The stores want to unload their old
stock, or are completely lacking in knowledge. Take your pick.
But, if the MB can handle it, ensure you get ECC capable memory.

--
Chuck F (cbfalconer at maineline dot net)
Available for consulting/temporary embedded and systems.
http://cbfalconer.home.att.net



--
Posted via a free Usenet account from http://www.teranews.com

On Oct 2, 10:31 pm, Igor wrote:
I'm planning to add some memory to a PC. The motherboard supports "DDR up
to 333 MHz (enhanced) memory bus."

333 MHz (PC2700) or slower DDR SDRAM isn't easy to find on today's market,
and when you do find it, it's considerably more expensive than the DDR
which runs at 400 MHz (PC3200). What would happen if I bought 400 MHz DDR
RAM and installed it in a motherboard which only supports speeds up to 333
MHz (PC2700)? Would it work? If it did work, would it work as well as the
slower PC2700 RAM?

I've gotten conflicting answers to this question. Two computer stores told
me that it wouldn't work. Another store and a book I consulted said it
would.


I don't understand this. You went into stores asking?!!!! You
consulted books?!!!

This is such an obvious question to ask. Lots of people have asked it
on usenet.

Didn't you think to search usenet?

you're concerned about price and asking on the internet, and it didn't
occur, or you lacked the confidence, to buy on the internet?!

I'd also like some opinions on which brand of RAM I should get. Kingston
and Samsung are ubiquitous where I live, so the choice comes down to one
of those. Both brands are about the same price, with the Samsung being
marginally cheaper.


GOOD MAKES OF RAM
this is an obvious search. You can read books but you can't use
google?!!!!
Kingston and Crucial are good makes. I seem to recall somebody here
saying one wasn't so good, but they work for most people. Don't get a
bad or unknown or unlabelled make / unbranded ram.


Finally, would a 128 MB stick of 266 MHz DDR RAM be able to run in the
same computer as, say, a 512 MB stick of 400 MHz DDR RAM?


you mean at the same time?
i'd try it. it's unlikely that the mbrd wouldn't like it, and even
then, it's unlikely that it'd smoke out.

If so, would
using both at the same time degrade the performance of the faster RAM?


I vaguely recall that they'd run at the slower speed. .

(Note: I'm using a bogus reply-to address to avoid spam, so please don't
reply by email.)

You know about spam, so learn how to search usenet. Your behaviour
doesn't seem logical. What kind of justification do you have?!

Igor wrote:

I'm planning to add some memory to a PC. The motherboard supports "DDR up
to 333 MHz (enhanced) memory bus."

333 MHz (PC2700) or slower DDR SDRAM isn't easy to find on today's market,
and when you do find it, it's considerably more expensive than the DDR
which runs at 400 MHz (PC3200). What would happen if I bought 400 MHz DDR
RAM and installed it in a motherboard which only supports speeds up to 333
MHz (PC2700)? Would it work? If it did work, would it work as well as the
slower PC2700 RAM?

The only time a good PC3200 module didn't work with one of my slower
mobos was when I set the mobo's BIOS to use the "safe" default
timings. That caused an ECS K7S5A Pro (max memory speed: 266 MHz) to
not boot and show only a completely blank screen.

I'd also like some opinions on which brand of RAM I should get. Kingston
and Samsung are ubiquitous where I live, so the choice comes down to one
of those. Both brands are about the same price, with the Samsung being
marginally cheaper.

I'd get Samsung because Samsung is a real RAM chip manufacturer while
Kingston just buys chips or silicon wafers from other companies and
doesn't seem to test them very thoroughly. About 20-30% of the
Kingstons I've tried were troublesome, with a whopping 8 out of 11-12
PC3200 512MB Kingston ValueRAMs failing. OTOH all 5 PC3200 512MB PNY
modules worked fine, even when overclocked (I don't normally
overclock). I strongly recommend testing each module overnight with
both MemTest86 AND Gold Memory.

Finally, would a 128 MB stick of 266 MHz DDR RAM be able to run in the
same computer as, say, a 512 MB stick of 400 MHz DDR RAM?

I was able to run a 256MB PC2100 and 512MB PC3200 together in a mobo
that supported 400 MHz. I don't know what happened to the timings of
the faster RAM.

On Tue, 02 Oct 2007 17:50:59 -0400, Paul wrote:

snip


If you tell us the motherboard make and model, we give better advice.

I don't see how that information is relevant to my two primary questions,
or even why it would be necessary to venture an answer to the third.
They're pretty general questions. Are you one of those guys who likes to
make everything more complicated than it needs to be?

On Wed, 03 Oct 2007 00:15:59 -0400,
wrote:

On Oct 2, 10:31 pm, Igor wrote:
I'm planning to add some memory to a PC. The motherboard supports "DDR
up
to 333 MHz (enhanced) memory bus."

333 MHz (PC2700) or slower DDR SDRAM isn't easy to find on today's
market,
and when you do find it, it's considerably more expensive than the DDR
which runs at 400 MHz (PC3200). What would happen if I bought 400 MHz
DDR
RAM and installed it in a motherboard which only supports speeds up to
333
MHz (PC2700)? Would it work? If it did work, would it work as well as
the
slower PC2700 RAM?

I've gotten conflicting answers to this question. Two computer stores
told
me that it wouldn't work. Another store and a book I consulted said it
would.


I don't understand this. You went into stores asking?!!!! You
consulted books?!!!

This is such an obvious question to ask. Lots of people have asked it
on usenet.

Didn't you think to search usenet?

you're concerned about price and asking on the internet, and it didn't
occur, or you lacked the confidence, to buy on the internet?!

I'd also like some opinions on which brand of RAM I should get. Kingston
and Samsung are ubiquitous where I live, so the choice comes down to one
of those. Both brands are about the same price, with the Samsung being
marginally cheaper.


GOOD MAKES OF RAM
this is an obvious search. You can read books but you can't use
google?!!!!
Kingston and Crucial are good makes. I seem to recall somebody here
saying one wasn't so good, but they work for most people. Don't get a
bad or unknown or unlabelled make / unbranded ram.


Finally, would a 128 MB stick of 266 MHz DDR RAM be able to run in the
same computer as, say, a 512 MB stick of 400 MHz DDR RAM?


you mean at the same time?
i'd try it. it's unlikely that the mbrd wouldn't like it, and even
then, it's unlikely that it'd smoke out.

If so, would
using both at the same time degrade the performance of the faster RAM?


I vaguely recall that they'd run at the slower speed. .

(Note: I'm using a bogus reply-to address to avoid spam, so please don't
reply by email.)

You know about spam, so learn how to search usenet. Your behaviour
doesn't seem logical. What kind of justification do you have?!





If you don't have anything intelligent to say, it's better that you don't
say anything at all.

On Tue, 02 Oct 2007 19:38:51 -0400, kony wrote:

snip



I'd also like some opinions on which brand of RAM I should get. Kingston
and Samsung are ubiquitous where I live, so the choice comes down to one
of those. Both brands are about the same price, with the Samsung being
marginally cheaper.

Which country do you reside in? Often buying online is
cheaper unless there's a particularly good sale or rebate
ongoing. Kingston's valueram tends to be lower spec, many
other name brand modules are better or cheaper for the same
specifications.



I live in Canada. Which Internet-based retailers would you recommend?

The more popular mailorder places in the U.S. won't ship to Canada, most
likely due to import/export restrictions.

I don't like eBay for a variety of reasons and will not do business
through them.

I looked at the prices at tigerdirect.ca and didn't find them to be
appreciably better than the computer stores in my neighbourhood (a $3 or
$4 difference, not counting shipping). Frankly, for such small potential
savings, I prefer the convenience of buying locally.

On Tue, 02 Oct 2007 20:32:30 -0400, CBFalconer
wrote:

snip

But, if the MB can handle it, ensure you get ECC capable memory.


My motherboard's manual doesn't say anything about supporting ECC, so I'll
assume that it doesn't.

However, I plan on putting together a PC from scratch in the near future,
so perhaps ECC support is something I should be looking for in a
motherboard.

In a nutshell, why is ECC capable memory more desirable?