Mixing RAM

[rfrasier]

Is it possible with an ASUS P5B LGA 775 Intel P965 Express ATX Intel Motherboard to have (2) 1 Gig sticks and (2) 512 Meg sticks? I know it is probably a dumb quetion, but was just wondering how I can get the 3 Gig max for XP.

 

[badge]

Is it possible with an ASUS P5B LGA 775 Intel P965 Express ATX Intel Motherboard to have (2) 1 Gig sticks and (2) 512 Meg sticks? I know it is probably a dumb quetion, but was just wondering how I can get the 3 Gig max for XP.

I use 2 x 1GB plus 2 x 512 every day in a dual boot Vista 32/Win XP machine. I use the same RAM part number, just different size DIMMS. The 32 bit OS's will not recognize and allocate the entire 3 GB depending on the components your system is using.

http://www.anandtech.com/systems/showdoc.aspx?i=2917&p=3

 

[rfrasier]

So, is 3 Gig of RAM not really useful with XP? Is 2 Gig enough? Thanks for the reply.

 

[badge]

So, is 3 Gig of RAM not really useful with XP? Is 2 Gig enough? Thanks for the reply.

Windows xp 32 bit OS will properly allocate up to 2 GB of RAM, not 3 GB. You can use 3GB like I do due to my dual boot with Vista. In windows xp 32 if you have 150 JPEG photos open doing photoshop cropping while crunchimg some vhs film to DVD from a third hard drive using a photo editing software, the 3 GB's will help. Otherwise 2 Gb in dual channel will suffice while performing most tasks you will encounter while using windows xp. HTH.

 

[rfrasier]

lol :lol:

Thanks. I think I'll stick with the 2 Gig for now (actually it's new and should be here tomorrow). I have a copy of Vista, but I'm holding off installing it for awhile. Maybe then I'll bump up to 4 Gig. Thanks for your help.

 

[badge]

Sounds good. Actually I was using 2 x 1GB plus 2 x 512. Right now I'm using 4 x 1 GB. Windows xp does not recognize 4 Gb, but it works fine. Same for Vista on my dual boot using the 4 x 1 GB. I planned on getting Vista 64, but I'm not sure my Slingbox Pro will run on Vista 64 and I like watching my DISH network at three locations like I do now.

 

[fishboi]

Seeing though this topic has been resolved, I had a simlar question. I was thinking about getting another 2GBs for my machine.

I wanted to know the pros and cons (specifically with respect to overclocking and the required voltages), of not going with the exact same set that I already have.

Thanks,

 

[badge]

Seeing though this topic has been resolved, I had a simlar question. I was thinking about getting another 2GBs for my machine.

I wanted to know the pros and cons (specifically with respect to overclocking and the required voltages), of not going with the exact same set that I already have.

Thanks,

I have both the e6600 and the q6600 I have used in the ASUS p5B Deluxe. With 3 GB, I could use the RAM mfg.'s recommended voltage of 2.0-2.1v and run fine. I overclocked the e6600 and had the 800 mhz. RAM running at 1000 mhz at 2.35v. One of the DIMMS burnt up while I left the machine on all week. With 4 GB I have to bump the voltage to 2.135 to get it to boot with the q6600. I like the q6600 so much I haven't even Oc'd it! The processor is idleing at 23c as I type. What fun!

 

[Mondoman]

So, is 3 Gig of RAM not really useful with XP? Is 2 Gig enough? Thanks for the reply.

Windows xp 32 bit OS will properly allocate up to 2 GB of RAM, not 3 GB....
To clarify, win xp will use 3GB no problem, and it will help heavily-loaded systems. However, normally Win will only allocate up to 2GB of memory *per program*; you'll have to go to 64-bit software (or use cumbersome software/hardware extensions) to easily get substantially more memory per program.

 

[badge]

So, is 3 Gig of RAM not really useful with XP? Is 2 Gig enough? Thanks for the reply.

Windows xp 32 bit OS will properly allocate up to 2 GB of RAM, not 3 GB....
To clarify, win xp will use 3GB no problem, and it will help heavily-loaded systems. However, normally Win will only allocate up to 2GB of memory *per program*; you'll have to go to 64-bit software (or use cumbersome software/hardware extensions) to easily get substantially more memory per program.

I moved from 3 Gb to 4 GB recently. My dual boot Vista 32/Win XP Pro both run 4 Gb, but neither OS properly recognize or allocate 4 GBs. I use Pinnacle studio video editing software from time to time in XP. I'm thinking the 4 Gb will be put to use in XP editing full lenght movies from a third HD. I intended to get Vista 64, but my internet cameras and my Slingbox Pro may not be usable from there. I should have stayed with my 2 x 1 Gb plus 2 x 512. I may get Vista 64 and have a tri-boot. The triumverate.

 

[fishboi]

Why will Windows not allocate more than 2GB per program? Does that mean that anything over 2GB is a waste?

How is the memory allocated when running multiple programs?

 

[badge]

Why will Windows not allocate more than 2GB per program? Does that mean that anything over 2GB is a waste?

How is the memory allocated when running multiple programs?

Mondoman can give you the more technical explanation. Vista uses a different method of allocating RAM than XP. XP will use more than 2 GBs, but it will not make use of over 2GBs in the same manner it uses the first two gigs. You have to have a 64 bit OS (XP or Vista) to fully utalize 4 GBs.

Here is an explanaton of Vista's ability to utalize system RAM.

http://www.anandtech.com/systems/showdoc.aspx?i=2917&p=4

 

[badge]

BTW I'm pretty sure my windows xp pro uses 4 x 1GB of PC6400 @ 890 mhz running in dual channel. So, yeah windows xp can run 4 GBs. I can double check later if you want me to.

 

[Mondoman]

Why will Windows not allocate more than 2GB per program? Does that mean that anything over 2GB is a waste?...

A design decision back in the dawn of 32-bit Windows development. Basically, they just took the 4GB max virtual address space and split it in half, with 2GB for an app and 2GB for the OS. Since even 2GB was much more memory than an app would ever use (this was in the days of tens of MB of *total* system RAM), no problem.
As real-world installed memory amounts started to get into the GB realm, Microsoft added an option to change the balance to 3GB app, 1GB OS. This /3GB switch needs to be specified when Win XP boots to change the balance. In addition, even with this mode activated, individual apps need to have been compiled specially to take advantage of the 3GB app address space, or they will still get only 2GB max.
Here's a link to a brief description of this topic: http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx

Physical memory over 2GB is not a waste and won't go unused (unless it overlaps with the addresses used for hardware, above the 3.0-3.5GB region, depending on the system's exact components).