Ram question (4gb limit)

I have windows vista (32 bit) so there is a 4gb maximum on ram. Atm i have 3 gb of ram. I'm looking into replacing the 3rd (odd) stick with a 2x1gb dual channel kit so i can actually use dual channel. This would bring me up to 4 gb, however. Would dual channel still work? Doesn't video card memory (512mb in my case) count towards the total as well?

thanks,
gimp

 

Yes, it does.

32-bit operating systems have a 4GB cap on memory, and that includes everything, not just RAM. So if you were to install a second identical videocard and run them in SLI mode, the total amount of RAM that your system will recognize goes down to 3GB.

However, your computer isn't going to use the three 1GB modules in slots one through three, and never acknowledge the fourth one. (If you ask your BIOS, it will report four functioning 1GB modules.) It will use up to 3-3.5GB, spread out however, and having four modules in dual channel will speed up data processing, regardless of how large a portion of each module the computer ends up using. So even if your computer can't read the full 4GB, it will read four modules in dual channel, and you'll get that benefit.

How large a difference that will make is another thing entirely, and not one I'm going to speculate on.

 

what is the speed difference between single channel and dual channel? (let assume same number of chips)

 

Speed difference, I can't really say. Generally speaking though, dual channel mode is supposed to give you about a 10% performance boost.

 

Not much about 5-10%

EDIT oops Mims beat me to it

 

ehh that probably isn't worth it- I've never come close to using the 3gb i have now, so the half gig capacity i'd gain (4 gb ram- 512mb vc = 3.5 gb ram) won't do me any good- i won't even notice a 10% speed boost either.

Mimsy, you said in your first post that spreading the load out to four modules instead of three is a pretty miniscule performance gain?

 

Well, that depends on what you use it for... I do gaming on my computer. I would notice a 5-10% performance drop.

 

From what I have read, Vista SP1 release will show 4 gig RAM, if 4 gigs installed.

You still have to deduct the RAM that your graphic card/s use, of course.

I guess that settles one niggle that Vista owners have about displayed RAM. Bazza

 

hmmm... i haven't bought Vista for this pc yet- i suppose i could get the 64 bit version.

 

If you do get the 64-bit version, there is a flash issue with it.

 

flash as in flash memory? or flash as in the backbone of killing time on the web?

resolvable?

 

My thread about the flash issue Enjoy