Dual Channel DDR

Quick question, hope it's not dumb, but I'm confused about a couple of
things in my quest to buy a new mobo and memory, which I will probably o/c.
Looking around, I'm thinking nForce2 and some sort of barton core. Here are
the questions:

Latency. Looked around, and didn't see any good explanations. For the same
DDR3200, some are rated at 2 or 2.5, others by this string of numbers, such
as 2-2-6-2. What does each mean - if memory is rated with a single latency
value (like crucial), does that mean they are trying to mask something?

Dual Channel DDR. This is more conceptual than anything else, but if I
install 2 x 256mb modules in dual mode, do I end up with 256mb "effective"
memory or 512mb? Read a good article in Kingston's site, but it was intel
based, which uses two pairs. It also compared 1x256(single) to 2x256 to
2x512(both dual channel), but never 2x256 to 1x512, which is a little
disingenous if, in fact, 2x256 = 512 effectively in dual channel mode. How
does it work when you have three banks, like nforce2 - can you use all three
banks and still be in the dual channel mode?

Sorry for long post.

p.s. - thinking about an Albatron kx18d pro ii, mainly because price and
"Dr. Pro" emailed me back within 4 hours of asking a question even though I
admitted I was shopping and not in possession. Any bad experiences with
them - back in the old days I had a pc-chips board and still have a shuttle
board and regret I ever bought them. Would like not to repeat.

"Joseph Sullivan" wrote
snip
Quick question, hope it's not dumb, but I'm confused about a couple of
things in my quest to buy a new mobo and memory, which I will probably
o/c.
Looking around, I'm thinking nForce2 and some sort of barton core. Here
are
the questions:

Dual Channel DDR. This is more conceptual than anything else, but if I
install 2 x 256mb modules in dual mode, do I end up with 256mb "effective"
memory or 512mb? Read a good article in Kingston's site, but it was intel
based, which uses two pairs. It also compared 1x256(single) to 2x256 to
2x512(both dual channel), but never 2x256 to 1x512, which is a little
disingenous if, in fact, 2x256 = 512 effectively in dual channel mode.
How
does it work when you have three banks, like nforce2 - can you use all
three
banks and still be in the dual channel mode?


Hi,
if you have two sticks of 256MB ram in dual-channel, it will equal 512MB!
It is then possible to add a single 512MB stick into the spare slot, so now
you will have 1GB of dual-channel
--
Wayne ][

Barton (AQXEA) XP2500+ @ 2.2GHz (10x220) - 1.775vCore
CoolerMaster Aero 7 Lite - 3,200rpm
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Antec SX630II Mini-Tower Case Inc 300w PSU
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Joseph Sullivan wrote:
Quick question, hope it's not dumb, but I'm confused about a couple of
things in my quest to buy a new mobo and memory, which I will probably
o/c. Looking around, I'm thinking nForce2 and some sort of barton core.
Here are the questions:

Latency. Looked around, and didn't see any good explanations. For the
same DDR3200, some are rated at 2 or 2.5, others by this string of
numbers, such as 2-2-6-2. What does each mean - if memory is rated with
a single latency value (like crucial), does that mean they are trying to
mask something?

As suggested check the Corsair guide. The reason many manufacturers only
qute the CAS Latency is becuase that one is more important (makes more
difference to the overall speed) than the other latencies.

Dual Channel DDR. This is more conceptual than anything else, but if I
install 2 x 256mb modules in dual mode, do I end up with 256mb "effective"
memory or 512mb?

512MB.

Read a good article in Kingston's site, but it was intel
based, which uses two pairs. It also compared 1x256(single) to 2x256 to
2x512(both dual channel), but never 2x256 to 1x512, which is a little
disingenous if, in fact, 2x256 = 512 effectively in dual channel mode.
How does it work when you have three banks, like nforce2 - can you use
all three banks and still be in the dual channel mode?

You can on nForce2, yes. You can use modules that are not matched in size,
so it's usually recomended to put the largest module on a channel on it's
own.

Ben
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