dual channel

[shupola]

i have read a few posts about dual channel ram. my question is: what exactly is it? what are the benefits? how is it different from any other type of ram? i have a compaq presario 2100 laptop so could i add dual channel ram if i wanted?

 

[mgoldb2]

i have read a few posts about dual channel ram. my question is: what exactly is it? what are the benefits? how is it different from any other type of ram? i have a compaq presario 2100 laptop so could i add dual channel ram if i wanted?

It increase the bandwidth of the ram. It has only minor benfits. dual channel is motherboard/cpu dependent not ram. meaning there not special dual channel ram. if you computer supports dual channel then any 2 indenticle ram sticks can run in dual channel.

 

[Praetor]

1. DDR memory has a 64bit interface.

2. With the 64bit interface, 200MHz memory (lets make that our baseline) is capable of a throughbout of 200Mhz*64bit÷(8bits/byte)*2(for the ddr) =3.2GB/s

3. The most effective way to improve performance would be to make it a 128bit interface and thus 200Mhz * 128 bit ÷ (8bits/byte) * 2 (for the DDR) =6.4GB/s

4. This is electrically complicated so its not done. What they can do however is to make two memory controllers work together in tandem (thus each stick of memory communicates at a full 3.2GB/s to the memory controller rather than 'sharing' a memory controller between them). Thus you have something like:
[200Mhz*64bit÷(8bits/byte)*2(for the ddr) =3.2GB/s] + [200Mhz*64bit÷(8bits/byte)*2(for the ddr) =3.2GB/s] = 6.4GB/s

 

[guernseynick]

I have a problem with figuring out compatibility with my RAM and motherboard
i will be getting a "Abit Fatal1ty AA8XE S775 PCI-E i925XE 1066FSB Gbit LAN 7.1Ch Audio USB2/1394" from www.scan.co.uk and its Ram spec is
"Four 240-pin DIMM sockets
Supports Dual channel DDR2 533/400 Unbuffered Non-ECC memory
Supports maximum memory capacity up to 4GB"
I am not sure what this all means.
Will i have to get 240 pin sticks and not go above 533/400 megahertz because many i have looked at have speeds of 675 MHz.

More simply can anyone reccomend a few 1 Gb set ups that would be compatible with my motherboard? (Abit Fatal1ty AA8XE S775 PCI-E i925XE 1066FSB Gbit LAN 7.1Ch Audio USB2/1394)

Thanks
Nick