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Dual Channel Memory

Community Veteran
Posts: 38,460
Thanks: 1,030
Fixes: 62
Registered: 15-06-2007

Dual Channel Memory

According to the bios on my latest motherboard the memory is running dual channel interlaced. This is an Intel P35 motherboard.
However another computer using an AMD socket 939 processor reports dual channel but doesn't mention interlacing.
Is this of any significance.
2 REPLIES
Community Veteran
Posts: 6,735
Thanks: 12
Registered: 02-02-2008

Re: Dual Channel Memory

Interlaced or interleaved?
I remember reading about this recently and found this which explains a bit:
Interleaved Mode - This is the mode of operation that enables the highest memory interface speed and bandwidth throughput capability. Often times this mode of operation is referred to as "dual-channel mode". Interleaved mode occurs when using two DIMM modules with equal memory capacities. The DIMM technology and device width can vary but the installed memory capacity for each channel must be equal. If different speed DIMMs are used in each channel then the slowest DIMM will determine the memory interface speed.
Asymmetric Mode - From a system operational standpoint, asymmetric mode functions as a "single-channel" memory interface. Asymmetric mode occurs when using either a single DIMM module or two DIMM modules with unequal memory capacities The DIMM technology and device width can vary in each channel and if different speed DIMMs are used in each channel then the slowest DIMM will determine the memory interface speed.
Ghozer
Grafter
Posts: 43
Registered: 06-02-2008

Re: Dual Channel Memory

Quote from: HPsauce
Interlaced or interleaved?
I remember reading about this recently and found this which explains a bit:
Interleaved Mode - This is the mode of operation that enables the highest memory interface speed and bandwidth throughput capability. Often times this mode of operation is referred to as "dual-channel mode". Interleaved mode occurs when using two DIMM modules with equal memory capacities. The DIMM technology and device width can vary but the installed memory capacity for each channel must be equal. If different speed DIMMs are used in each channel then the slowest DIMM will determine the memory interface speed.
Asymmetric Mode - From a system operational standpoint, asymmetric mode functions as a "single-channel" memory interface. Asymmetric mode occurs when using either a single DIMM module or two DIMM modules with unequal memory capacities The DIMM technology and device width can vary in each channel and if different speed DIMMs are used in each channel then the slowest DIMM will determine the memory interface speed.


Its not just "" when using two DIMM modules with equal memory capacities. "" - the memory address mapping has to be the same, it has to be the same number of chips on the module, and has to be the same latencies, and even then it may not be perfect, the only way you will get 100% garunteed 'true' full speed dual channel is to use a dual channel kit, this means the modules are as closely matched as possible (came off the production line at the same time, one after the other for example)
often, dual channel has to use the odd memory slots on your system board.. these are often blue, if your board has 3 memory slots, you can use the odd (outer 2) for dual channel..
heres how it should be configured / setup, ( x = not used / empty )
3 Slot configuration:
1 - x - 3
4 Slot configuration:
1 - x - 3 - x
x - 2 - x - 4
1 - (2) - 3 - (4)
In my machine, I have 3GB total, in this configuration,
Slot 1: 1GB
Slot 2: 512MB
Slot 3: 1GB
Slot 4: 512MB

as well as dual channel, there are many other options you can tweak to increse memory throughput / bandwidth WITHOUT overclocking / damaging your ram