Question about Dual Channel Memory

[Brian K]

Mobo: Machspeed K8M8MSR2
OS: Windows XP SP 2 Home Ed.
CPU: AMD 64 3700+

Question: I got my motherboard as part of a barebones kit. It came with
an Ultra 512 mb PC3200 DDR 400 Mhz CL3 module. I want to add another
512 mb module to upgrade to 1g. This Machspeed board runs Dual
Channel. The memory I want to add is a Kingston Value Ram with these
specs: 512 mb, PC3200, DDR 400 Mhz, CL3. They are both 184 - pin DIMM.

My question is can I use it or do I need to put in another Ultra memory
stick?

My last machine I built was an Intel P-III class machine. On that one I
could mix and match memory sticks in terms of size as long as they were
PC 100. So, there's a learning curve for me regarding Dual Channel.
Pardon me if this is something that everyone knows the answer and
considers dumb.

--
________
To email me, Edit "blog" from my email address.
Brian M. Kochera
"Some mistakes are too much fun to only make once!"
View My Web Page: http://home.earthlink.net/~brian1951

 

[Randella]

It looks like you have everything 100% correct. Just make sure that
you insert the sticks in the correct banks to use the dual channel
ability of your MOBO.

Good Luck!!!

-Randy

 

[Paul]

Mobo: Machspeed K8M8MSR2
OS: Windows XP SP 2 Home Ed.
CPU: AMD 64 3700+

Question: I got my motherboard as part of a barebones kit. It came with
an Ultra 512 mb PC3200 DDR 400 Mhz CL3 module. I want to add another
512 mb module to upgrade to 1g. This Machspeed board runs Dual
Channel. The memory I want to add is a Kingston Value Ram with these
specs: 512 mb, PC3200, DDR 400 Mhz, CL3. They are both 184 - pin DIMM.

My question is can I use it or do I need to put in another Ultra memory
stick?

My last machine I built was an Intel P-III class machine. On that one I
could mix and match memory sticks in terms of size as long as they were
PC 100. So, there's a learning curve for me regarding Dual Channel.
Pardon me if this is something that everyone knows the answer and
considers dumb.

If this is a socket 754, then despite the misrepresentation in
the advertisement, it is a single channel memory interface.
There are two memory slots, but they sit on the same bus.
That is determined by the AMD processor and not the motherboard.
(Socket 939 processors support dual channel memory.)

Machspeed is the same thing as Jetway.

http://www.machspeed.com/specs/viper/vik8m8ms.htm
http://www.weirdstuff.com/cgi-bin/item/15165

What should happen, is the memory bandwidth should drop when
the second DIMM is added. That is because the BIOS will either
reduce the memory clock, or it will use Command Rate 2T. You
can inspect the eventual settings with CPUZ or perhaps
A64Tweaker, after the second DIMM is added.

Since it is a single channel memory interface, there is no
reason to match the DIMMs, so the two you are planning on
using above should be OK. How cranky a motherboard is about
RAM, is frequently determined by the quality of the BIOS
code provided with the motherboard. Even the major manufacturers
like Asus, have got that wrong on occasion.

Paul

 

[Brian K]

If this is a socket 754, then despite the misrepresentation in
the advertisement, it is a single channel memory interface.
There are two memory slots, but they sit on the same bus.
That is determined by the AMD processor and not the motherboard.
(Socket 939 processors support dual channel memory.)

Machspeed is the same thing as Jetway.

http://www.machspeed.com/specs/viper/vik8m8ms.htm
http://www.weirdstuff.com/cgi-bin/item/15165

What should happen, is the memory bandwidth should drop when
the second DIMM is added. That is because the BIOS will either
reduce the memory clock, or it will use Command Rate 2T. You
can inspect the eventual settings with CPUZ or perhaps
A64Tweaker, after the second DIMM is added.

Since it is a single channel memory interface, there is no
reason to match the DIMMs, so the two you are planning on
using above should be OK. How cranky a motherboard is about
RAM, is frequently determined by the quality of the BIOS
code provided with the motherboard. Even the major manufacturers
like Asus, have got that wrong on occasion.

Paul

Thanks for your input. In addition to the advertisement, the K8M8MSR2
motherboard manual identifies it as dual channel memory. I'd rather err
on the side of caution. So assuming that the motherboard has a dual
channel interface for the two slots, are the two sticks under discussion ok?

--
________
To email me, Edit "blog" from my email address.
Brian M. Kochera
"Some mistakes are too much fun to only make once!"
View My Web Page: http://home.earthlink.net/~brian1951

 

[mike]

to run dual channel, all modules need to be the same.

for MBs with AMD CPUs:

the memory hub is part of the processor.
You should check the AMD site for memory that fits your processor.
Some memory will even only fit certain processor steppings, depending on
the CPU you have.

for MBs with Intel CPUs (just in case someone asks then...):

the memory hub is part of the MB.
Check the MB vendor's site, or if you know the 'northbridge', check on the
Intel site what memory your 'northbridge' supports. Some call the
'northbridge' a memory hub.



Why check these:

using the memory off the lists will result in a working system (if
everything else is ok...).

That does not mean other memory won't work.

However, since you need to buy it first, and stores usually don't take
memory back once the seal of the package is broken: better safe than sorry.

You can also bring your system to a store and have them fit memory in, and
test it out. Memtest is not a memory test, but a memory diagnostic.
Memtest may run fine, while the system may not boot to your preferred OS.

Adding/removing memory tips:

pull the power plug
hit the power button (drain 5V, if the system is open you may see the
fans twitch, the MB 5V LED should be off after that,

Do what you need to do with the physical memory sticks.

When you boot up (press f2, del, altwhatever, depending on your MB, to
get into the BIOS; on most Intel MBs pull the BIOS jumper so it goes into
the BIOS screen without anything else).

redo your BIOS settings this way:
load defaults (that's on the main BIOS menu,
save, exit, reboot, power off while it is in the reboot post,
power back on into BIOS,
redo your BIOS settings if you usually run any changes).

This way you are sure all PCI stuff is cleared out and your BIOS has
latched in the new memory SPD data, and if capable, optimized the memory
timings for you (some MBs Bios' do that, some don't).

Sure, you can just clear the BIOS using the jumper. But if it won't work
you have to go back and do any or all of the above.

Leaving 5V on the MB while changing memory (even while taking out the old
one) may kill your memory.

Mike

 

[Brian K]

to run dual channel, all modules need to be the same.

for MBs with AMD CPUs:

the memory hub is part of the processor.
You should check the AMD site for memory that fits your processor.
Some memory will even only fit certain processor steppings, depending on
the CPU you have.

for MBs with Intel CPUs (just in case someone asks then...):

the memory hub is part of the MB.
Check the MB vendor's site, or if you know the 'northbridge', check on the
Intel site what memory your 'northbridge' supports. Some call the
'northbridge' a memory hub.



Why check these:

using the memory off the lists will result in a working system (if
everything else is ok...).

That does not mean other memory won't work.

However, since you need to buy it first, and stores usually don't take
memory back once the seal of the package is broken: better safe than sorry.

You can also bring your system to a store and have them fit memory in, and
test it out. Memtest is not a memory test, but a memory diagnostic.
Memtest may run fine, while the system may not boot to your preferred OS.

Adding/removing memory tips:

pull the power plug
hit the power button (drain 5V, if the system is open you may see the
fans twitch, the MB 5V LED should be off after that,

Do what you need to do with the physical memory sticks.

When you boot up (press f2, del, altwhatever, depending on your MB, to
get into the BIOS; on most Intel MBs pull the BIOS jumper so it goes into
the BIOS screen without anything else).

redo your BIOS settings this way:
load defaults (that's on the main BIOS menu,
save, exit, reboot, power off while it is in the reboot post,
power back on into BIOS,
redo your BIOS settings if you usually run any changes).

This way you are sure all PCI stuff is cleared out and your BIOS has
latched in the new memory SPD data, and if capable, optimized the memory
timings for you (some MBs Bios' do that, some don't).

Sure, you can just clear the BIOS using the jumper. But if it won't work
you have to go back and do any or all of the above.

Leaving 5V on the MB while changing memory (even while taking out the old
one) may kill your memory.

Mike

Thanks everyone. I followed your suggestions. You were correct, the
mobo is single channel. The memory has been installed and everything is
running great.

Thanks again.

--
________
To email me, Edit "blog" from my email address.
Brian M. Kochera
"Some mistakes are too much fun to only make once!"
View My Web Page: http://home.earthlink.net/~brian1951