Dual channel memory w/ Athlon64

[Head Hunter]

Does a motherboard exist that takes the Athlon 64 (not the 64FX) and
supports dual-channel memory? I have searched various Mfr's and searched
Google, but haven't found any.

Also, is there a reason to get dual-channel memory (2 DIMMs) vs just getting
2 DIMMS of the same DDR? I have seen 512 MB dual-channel memory (I assume 2
x 256MB) for twice the price of a single 512MB DIMM. Why can't I get the
two 512 MB DIMMs and have it act as dual-channel? That way I can get 1GB
for less than the price of the 512MB dual-channel.

 

[Dave C.]

Does a motherboard exist that takes the Athlon 64 (not the 64FX) and
supports dual-channel memory? I have searched various Mfr's and searched
Google, but haven't found any.

Also, is there a reason to get dual-channel memory (2 DIMMs) vs just getting
2 DIMMS of the same DDR? I have seen 512 MB dual-channel memory (I assume 2
x 256MB) for twice the price of a single 512MB DIMM. Why can't I get the
two 512 MB DIMMs and have it act as dual-channel? That way I can get 1GB
for less than the price of the 512MB dual-channel.

OK, I could be wrong, but I believe the Athlon 64 has the MCC (memory
controller) built into the CPU. Thus, dual-channel memory would be a
function of the CPU, IF the Athlon 64 supported this function. So if you
can't find a motherboard with this function, I'm guessing it's not a
function that AMD put in the Athlon 64 chip.

But if you want to run dual-channel memory, you do not need an exact matched
pair. This is a marketing scam to sell two RAM boards for four times the
cost of a single RAM board. You can get two 512MB RAM boards and run them
as dual-channel. The computer I'm typing on right now uses (two) 512MB
Kinsgston brand PC2700 sticks, and runs them just fine in dual channel mode.
I purchased the two sticks separately. -Dave

 

[Fitz]

Dave is correct- the memory controller is built into the AMD64 chip and
there isn't a motherboard for it that supports Dual Channel DDR. There is no
reason to buy "matched" pairs of memory, other than it is the easiest way to
buy 2 DIMMS of the same memory.

The AMD64 does not require ECC memory, but be careful about what you
buy...it can be picky about what it will run. Make sure you look at the
"recommended" list from AMD or the motherboard manufactuer. I'm running
2X512 GB of Kingston HyperX PC3200. My Gigabyte motherboard will not hold
CL2 settings for the memory and I'm having to run it at CL 2.5. If I had it
to do over again, I would have bought Cosair, Geil, or Mushkin.

Go here and do some reading: http://forums.amd.com/index.php?
Lots of references and discusssion about memory for the AMD64.

Before you worry about the lack of Dual Channel support, keep in mind that
performance is very good because of the 64 bit technology and the
Hyper-Transport Link. You realize a performance boost even without a 64 bit
OS just due to the number of additional "pathways" for data to travel on
(very oversimplified- for my benefit, not yours!)

My system is a Gigabyte K8NNXP w/AMD64 3200+
1GB Kingston HyperX PC3200/ 2 X WD SATA 36GB Raptors (RAID 0)/ 1 IBM IDE
Deskstar\ATI 9800 Pro video\M-Audio Revolution 7.1 audio\Plextor 708A DVD
RW\Antec TruPower 430W PS\A couple other add ons.

With no tweaks other than "Best Performance" enabled in the BIOS (resulting
in a mild overclock to 2080 MHz, memory at 416 MHz and video at 67) my
AquaMark 3 score is slightly over 43000. File storage benchmark in SiSandra
2004 is off the scale.

It's a good system- I'm happy with it.

Fitz

 

[somebody]

Does a motherboard exist that takes the Athlon 64 (not the 64FX) and
supports dual-channel memory? I have searched various Mfr's and searched
Google, but haven't found any.

No not yet. But soon.

Socket 754 is essentially single channel, as the socket 754 Athlon64s
have a single channel memory controller. There may be tricks played
with this eventually, as the ultimate capacity of that controller can
be quite large. AMD has murmured something about technologies to speed
up memory.

You'll have to wait for socket 939, for dual channel. Most early
Socket 939 Athlon64s looks set to get smaller caches though, to keep
cost down.

ancra

 

[DaveW]

Because running in 'dual channel' mode requires perfect timing matchups
between the sticks. If you use two randomly chosen sticks of the same model
of 512 MB DDR RAM it will run as 1 GB of RAM, but will NOT run in dual
channel mode. There's a good reason why dual channel pairs cost more.

 

[Clyde]

Because running in 'dual channel' mode requires perfect timing matchups
between the sticks. If you use two randomly chosen sticks of the same model
of 512 MB DDR RAM it will run as 1 GB of RAM, but will NOT run in dual
channel mode. There's a good reason why dual channel pairs cost more.

I am running two non-tested 512 chunks of Corsair in my dual channel
Intel D865GBF with P4 3.0 GHz. They are from the same batch though and
they are CL2. They run in dual channel mode just fine.

Before saving that money I did some research and asking around. Most
people said that if you get a good brand of memory, regular stuff should
run just in dual channel mode.

Clyde

 

[Matt]

Because running in 'dual channel' mode requires perfect timing matchups
between the sticks. If you use two randomly chosen sticks of the same model
of 512 MB DDR RAM it will run as 1 GB of RAM, but will NOT run in dual
channel mode. There's a good reason why dual channel pairs cost more.

You gave a very definite answer again. Also one that is definitely
wrong. Again.

 

[Matt]

Also, is there a reason to get dual-channel memory (2 DIMMs) vs just getting
2 DIMMS of the same DDR? I have seen 512 MB dual-channel memory (I assume 2
x 256MB) for twice the price of a single 512MB DIMM. Why can't I get the
two 512 MB DIMMs and have it act as dual-channel? That way I can get 1GB
for less than the price of the 512MB dual-channel.

Generally the RAM sticks don't have to be matched, and they don't even
have to be from the same manufacturer. But I expect in a few cases a
matched pair will work where an unmatched pair won't.

I believe dual channel is not usually much of an advantage unless your
video chip shares memory with the CPU (eg nforce2 chipset with on-chip
graphics) or you are running a P4 with hyperthreading technology (HT).

 

[Dave C.]

Because running in 'dual channel' mode requires perfect timing matchups
between the sticks. If you use two randomly chosen sticks of the same model
of 512 MB DDR RAM it will run as 1 GB of RAM, but will NOT run in dual
channel mode. There's a good reason why dual channel pairs cost more.

That is illogical, as the timing is supplied by the motherboard. Thus, two
randomly chosen sticks of the same model of 512MB DDR RAM will have perfect
timing matchups, unless there is something seriously wrong with THE
MOTHERBOARD. -Dave (running dual channel on two randomly chosen sticks of
the same model of 512MB DDR RAM)