Quick Dual Channel Benefit Question

[essential]

I understand this question has probably been asked in the past, but I'm at work, and don't have time to search and look around. I'm hoping to order a laptop during my lunch break, but I have one $100 question:

It costs $100 to upgrade from 3GB of RAM to 4GB of RAM. I know a 32-bit OS can only see about 3.25GB of RAM, but with 4GB you get the benefit of dual channel mode, and with 3GB you don't. Are the performance gains with dual channel mode worth the extra $100 even though only about 200megs of the extra gig will be usable in the system?

Thank You!

 

[Denithor]

No.

And btw, you can add more memory yourself later much, much cheaper than the OEMs will sell it to you. Just go to crucial.com and use their memory matcher tool. They guarantee compatibility with your system...

 

[Spivonious]

You will see gains but it's not worth $100.

 

[Denithor]

DDR2-960 versus DDR2-1200

Ok, if you want to call 1-2fps in HL2 and Crysis a difference, I suppose I won't argue. But I certainly wouldn't spend $100 extra for 1-2fps...

 

[tcsenter]

Originally posted by: essential
It costs $100 to upgrade from 3GB of RAM to 4GB of RAM. I know a 32-bit OS can only see about 3.25GB of RAM, but with 4GB you get the benefit of dual channel mode, and with 3GB you don't.

Depending on the chipset, 3GB doesn't necessarily mean single channel. Some chipsets can support asymmetric dual channel (a.k.a. flex) mode that performs somewhere between single and dual channel mode.

 

[nefariouscaine]

Originally posted by: tcsenter

Originally posted by: essential
It costs $100 to upgrade from 3GB of RAM to 4GB of RAM. I know a 32-bit OS can only see about 3.25GB of RAM, but with 4GB you get the benefit of dual channel mode, and with 3GB you don't.

Depending on the chipset, 3GB doesn't necessarily mean single channel. Some chipsets can support asymmetric dual channel (a.k.a. flex) mode that performs somewhere between single and dual channel mode.

Most boards support this - current intel boards anyways - different size isn't the issue - you just don't have the ability to run separate speeds/timings/voltages - IE all 4 sticks (2 matching pairs of 2) need to run at the same specs

I've done comparisons on memory speeds, timings, all that jazz - most of the time you won't see much benefit on dual channel vs single channel - not if you are just using every day apps - notable is speed increase in say zipping a file or as stated maybe 5 fps in a game (tops) and while that could be the difference of smooth game play or not $100 can be invested in other areas to increase speed more (newer CPU for example)