i6000d: Additional RAM and dual chanel?

Hi,

I've heard that in order for the DDR2 400Mhz RAM to work in dual channel on the Sonoma plateform such as in the i6000d, both RAM chips must be exactly the same (so both should also have the same size!).

I'm interested in getting a i6000d which comes with 768Mb RAM as standard (available on the Swiss market) so it means there will be one 512Mb chip and one 256Mb chip. Do you know if this will inevitably cause the RAM not to operate in dual channel??? Is the benefit of dual channel very important??

Many thanks for your help

 

No, it will not operate as dual channel. Both sticks of RAM must be virtually identical. (Even 2 of the same sticks produced by the same company 2 weeks apart are unlikely to be recognized as dual channel.)

The performance increase of dual channel vs non-dual channel is significant but not huge.

 

And stupid question: if I get 1 stick of 512Mb or 1024Mb RAM, will it work as dual channel??? (is dual channel only meanful when there are 2 memory sticks?)

Thanks

 

Both Sticks must be identical, meaning they must be the same size as well as manufacturer, etc..., so no, that won't work either. Example of what would:
2x 512mb sold as a pair

 

<blockquote id='quote'> quote:<hr height='1' noshade id='quote'>Originally posted by ramos

 

Here is a clear comparison benchmarking between using a single dual mode ram module and using two modules (which is what dual channel needs to operate):
http://www.devhardware.com/index2.php?option=content&task=view&id=993&pop=1&page=0&hide_js=1
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I have a similar question, when upgrading ram, will I need to install them in pairs? So would I have to get 2 X 512 or can I just get one 1gb and still keep one the 256mb (pre-installed with 2x256)?

 

<blockquote id='quote'> quote:<hr height='1' noshade id='quote'>Originally posted by kilou

 

DDR2 Memory In Dual-channel Mode Does (hardly) Anything In Practice

http://www.tomshardware.com/mobile/20050119/sonoma_alviso-23.html

If you're buying a single stick instead of two so you can upgrade in the future, that's not a bad way to go, you're not loosing out much on performance from dual channel. If you know you'll never buy memory again, two sticks are probably cheaper than one for the same amount of memory, and you do get a few percent for dual channel, but don't buy two 512mb's if you plan to get two 1gb's in six months, just do a single 1gb now and another when you can later, you're not missing out much because it isn't dual channel. It's not like it is going to run at half speed or anything close, the dual channel performance gain is very small, only a couple of percent, you may be able to benchmark it and see it, but you'll never notice it using the machine.