New Notebook: 3gb or 4gb RAM?

Brief History:
I have Vista 32 bit, and Core 2 Duo. I know Vista will only address 3gb-3.5gb of RAM in my system. Of course RAM cost is not an issue in this day and age.


The Problem:

Will the benefit from dual channel when 2x2gb is installed be better than the 1x2gb and 1x1gb (total 3gb). If I'm not mistaken, if I instal 3gb in my notebook - 2gb would be in dual channel and the remaining 1gb would be single.

Where as with 2 x 2gb all 3-3.5gb is run dual channel.

I know the 2 x2gb would have overall better performance since all of it runs dual-channel - but is it significantly better than the 3gb with 2gb running dual channel and 1gb running single channel.


The Uses:

Photoshop, Dreamweaver, Flash, Adobe Premiere (No gaming!), and generlly have multiple programs running.

Sorry - forgot to mention, currently have 1 x 1gb ddr2 5300, 667 installed.

So it's a question of either just buying 1 x 2gb to add on to the 1gb

or

2 x 2gb and replace the 1gb

I don't have any benchmarks off hand to prove that dual-channel technology is worth using. And since you are not taking advantage of it currently, you may as well start.

You have/need to buy RAM currently so getting 4gigs makes a lot of sense.

For one, maxing at your RAM capacity now is reasonable because replacing all your current RAM in the future (with 2x2gigs) later makes less sense.

Second, you have a Core 2 Duo. Run dual channel!

Third, Adobe Suite loves to use 3gigs of RAM.


Edit:

The only reason I can think of not to go with 4gigs, is if you don't have 80$. I'd would foremost answer that with: Save your money and buy it then. But if you desperately, or will never have 80$ to spend, going with a 2gig stick (and not running dual-channel) would be advised - but hardly.

I decided to go with 3gb Crucial memory - ddr2 5300, 667.

One thing I can tell you is that when I have 2gb (2 x 1gb) in there it seems all performance is better than 3gb - (1 x 1gb) + (1 x 2gb).

When I say performance I mean memory latency, write and read.

Both scenarios report that I am indeed in dual channel - but of course we know with the 3gb setup the 1gb is in single channel.

So - how big was the performance hit?

Not to great - can't remember the exact result but I do recall it was about 100-200 point difference for read and write to memory. Reference being 2gb was around 4700 for read and 4900 for write (would that mb/s???).

I know latency was slightly less as well with the 3gb - but less than 2% difference.

That said - windows index also went down from 4.7 to 4.5!

I will say this though - there is no noticeable difference between 2gb and 3gb - Photoshop of course will love the 3gb setup more - regardless of that silly windows index!

And yes it boots up quicker and shuts down quicker with the 2 and 3gb setups than when it just had the 1gb.

I also stuck 2 x 512mb in there just to see what I would get. Windows Index was a resounding 4.6 - which highlights just how silly the index really is. I guess because all the memory was dual channel in that setup.

I used Everest and windows index for my Memory tests.

considering the applications you wanna use i think you aere better off with 4 GB

Get 4gb, that way, later on you aren't stuck buying a new notebook as fast b/c your current one will still go quick.