6GB Single Channel vs 4GB Dual Channel

I am buying a Sandy Bridge Core i-5 ThinkPad with 2x2gb 1333 mhz DDR3. I have an aftermarket 4gb stick that I want to replace one of the 2GB DIMMs with (the one that's easily accessible).

I have been searching the web for a definitive answer but don't seem to be able to make a conclusion based on what people are saying.

Can someone opine on whether it is better for me to keep the dual-channel 2x2Gb setup rather than having a single channel 6GB configuration. Thanks.

 

Put the stick in.

(However, I still recommend to matched 4GB modules instead).

2x 2GB (4GB total) will still be in dual channel and 2GB will be in single channel.

Overall, your system will be much smoother (and your WEI score should also improve).

Good luck.

 

If you don't need 6gb use the dual-channel 4gb. If you need 6gb, well..

 

Use 6GB regardless.

 

There is no such thing as 6GB single channel. If you use a 2GB stick and 4GB stick, then it will run asynchonous dual channel. Either way, as Hungry Man stated, 6GB is always better than 4GB. Whether or not you notice the difference depends on your uses.

 

Thanks much to everybody!!!

 

what kind of uses would notice a hit if you use async 6gb?

 

oh noes! that would hinder my productivity!

 

It's literally a free upgrade with no reason not to. Of course he should. There are no detrimental effects.

 

As most already said more RAM is always better than faster RAM. If you could find it, slap 4GB of PC133 and then stick a 1GB DDR3-1666 or whatever in similar systems and tells me which runs better.... i'll wait

Dual-channel wouldn't make much benefit anyways even when compared to same amount of RAM just not in DC mode. IN your case though 6GB will definitely run better than 4GB even if you don't need apps that need that much RAM. Windows itself will make use of it.

 

It is literally dual channel either way.

 

Performance wise, there would be no difference even if you lost dual channel.
Though Windows and programs would likely 'feel happier' with 6GB at their disposal (depending on what you are doing and provided you are using an x64 OS).

 

More RAM capacity is always better than less but unless your match the SODIMM's exactly you'll lose some memory performance due to asymmetrical dual channel mode.

The link below explains it in appropriate detail.

Intel Flex Memory Technology & mixing different capacity SODIMM's in laptops that support it

 

While in theory and benchmarks this is true, in real life, you will not notice any decrease in performance since bandwidth is never the bottleneck (unless running a stressful GPU program on integrated graphics).