DDR questions

[Alon Brodski]

Hello!

Couple of things are unclear to me about DDR technology.
1) Dual-channel DDR...the memory modules (actually the pairs of 2 identical
ones) that are used...Are they REGULAR DDR modules that CAN be used on a
single channel Mo-bo just fine in one by one configuration,or are they
specially designed for dual-channeling?
My guess-it's the 1st...
2)I heard that the best thing for the PC perfomance if FSB and memory runs
at the same speed.Say 800 MHz FSB and dual-channel DDR400 or 800 MHz FSB and
DDR2-800 etc.
So my quesion is...is it a REQUIREMENT or a preference? In other words,say
if I have 400 MHZ FSB and DDR333...Can I still use this kinda configuration?
Won't it damage anything? or it would work fine,just a little slower only?

Alon

 

[Ghostrider]

Hello!

Couple of things are unclear to me about DDR technology.

1) Dual-channel DDR...the memory modules (actually the pairs of 2 identical
ones) that are used...Are they REGULAR DDR modules that CAN be used on a
single channel Mo-bo just fine in one by one configuration,or are they
specially designed for dual-channeling?

My guess-it's the 1st...
Correct.

2)I heard that the best thing for the PC perfomance if FSB and memory runs
at the same speed.Say 800 MHz FSB and dual-channel DDR400 or 800 MHz FSB and
DDR2-800 etc.

So my quesion is...is it a REQUIREMENT or a preference? In other words,say
if I have 400 MHZ FSB and DDR333...Can I still use this kinda configuration?
Won't it damage anything? or it would work fine,just a little slower only?

Read the motherboard manual. It could be a requirement, if not
a preference. And, usually, there is no damage that can be done.
The motherboard will either not function or it will operate at
less than specified performance.

 

[RJK]

I sympathize !!

It's getting a bit daft now - i.e. hardware spec's and configuration. I
used to find it interesting and reasonably easy to understand but, during
the past year or two I haven't had the time to "read up for pleasure" and
keep up to date with the various newer motherboard features and marketing
CRAP !!!!!

Which leaves me wondering why the "hyperthreading" feature, in the bios, on
AMD cpu based / single memory channel Socket 754 boards seems happy to set
itself to 800mhz when the board is only fitted with ddr333/pc2700, because
it's only fitted with a Sempron 2800 which only requires ddr333 (fsb running
at 166mhz), ....could this be something to do with a quad-pumped "something
or other" inside the cpu...LOL !!! ...in other words the marketing CRAP
seems always to cause unnecessary confusion !!!

AEONS ago, 72 pin SIMM memory based motherboards used to feature "page
interleave" or "memory bank switching" and it was just there - as a
necessary hardware design feature - that provided some necessary improvement
in performance. ..then it was quietly dropped / or only featured on more
expensive motherboards. ...then Intel introduced a Celeron cpu WITH NO
Level 2 CACHE ..and people started wondering why their hard-disks sounded
like they had terminal flatulence !! ...then .. WOW!!!! ...page
interleave came back again as "dual channel"

.... I wouldn't be surprised if the motherboard industry suddenly decided put
sockets for memory controller memory on motherboards, and secretly doing
away with integrating memory controller circuitry on the cpu itself, ...that
seems to be happening nowadays unless I've misread something somewhere !

....and as for Socket 754 going by the wayside, ..for AM2 ....I'm beginning
to think that AMD don't deserve my "support" !!!

regards, Richard