T61 with 1 GB: Add 2 GB?

[IJALB]

I've a T61 with 1 GB and I want to put more RAM into it.

I'm not sure which way is the best:
Add 1 GB to have 2 GB?
Add 2 GB to have 3 GB?
Replace the 1 GB and buy two new 2 GB to have 4 GB?

I'm using Visa 32 Bit and so I can not use more than 3 GB. Even if SP1 would know the 4 GB, I guess it will only use 3 GB.
If I buy a new 1 GB (1+1=2), the RAM will run in Dual Channel Mode.
If I buy a new 2 GB (1+2=3), the RAM will not run with Dual Channel Mode but I have 1 GB RAM more.
If I buy two 2 GB (2+2=4 => 3) I'm not sure if the RAM will run in Dual Channel Mode (because Vista 32 can only use 3 GB but I guess it's just a method of the chipset and it doesn't care about Visa 32 bit and DCM will be active). Are there any problems with running Vista 32 bit with 4 GB? I think there've been problems with the T60 and/or WinXP?
Or is it better to have 3 GB installed instead of 2 GB with Dual Channel Mode?
I don't know what I should do.

[Harryc]

2x2GB is so cheap now that I recommend getting it and being satisfied with 3GB available running dual channel for the added performance. Ideally you'd want to run Vista 64 bit. Even if that's not an option now for one personal reason or another, perhaps someday soon you'll want to run a 64 bit OS and with 4GB RAM you'll be ready ....

[erik]

you probably won't notice any difference with dual-channel mode so it's more a matter of what you can afford.   my X61 runs extremely well with only 2GB under vista business 32.   unless you're using a lot of memory-heavy applications then 1+1GB or 2+1GB would be perfectly fine.

you can always add more memory later as it gets cheaper by the day.   i paid $260 USD for 2+2GB crucial modules three months ago and now the same modules are only $115 for the pair.   other brands are even less expensive.

[madcow]

You can get 4 G of RAM for less than $100. I'm sure it is probably $10 difference if you get 3 G of RAM. Who knows, you might move to 64 Operating System someday.

[Harryc]

You can get 4 G of RAM for less than $100. I'm sure it is probably $10 difference if you get 3 G of RAM. Who knows, you might move to 64 Operating System someday.

I could have said that...oh wait, I did . Seriously, I just paid $60 shipped (after rebate) for 4GB OCZ PC5400 at Frys online yesterday. It's so ridiculously cheap that 4GB is a no-brainer.
http://shop4.outpost.com/product/5284717

[madcow]

You can get 4 G of RAM for less than $100. I'm sure it is probably $10 difference if you get 3 G of RAM. Who knows, you might move to 64 Operating System someday.

I could have said that...oh wait, I did . Seriously, I just paid $60 shipped (after rebate) for 4GB OCZ PC5400 at Frys online yesterday. It's so ridiculously cheap that 4GB is a no-brainer.
http://shop4.outpost.com/product/5284717

It cost $700 to configure a macbook pro to 4 G of RAM. What's going on?

[pae77]

The manufacturers, especially Apple, like to take advantage of people who don't know enough to figure out what parts to buy and shop around for the best price and not be afraid to install them themselves.