Is my RAM dual channel mode?

[djforeman]

Is there a setting somewhere in Windows, or is there a program I can run, that will tell me if my RAM is actually running in dual channel mode? I have identical DDR400 SIMMS in slots 1 & 3 of my ASUS P4P80E-DLX mobo. I know they SHOULD be in dual channel mode. I want to confirm it.

Also, if I add SIMMs in slots 2 & 4, do they have to be the same SIZE as the ones in slots 1 & 3 inorder to stay in dual channel mode? I saw a post that says yes, but that's never been confirmed and some sources say it doesn't matter, as long as the SIMMs are matched in their banks. I've also posted this to the ASUS help-desk.

 

[LipsOfVenom]

here's a program http://www.cpuid.com/cpuz.php

just click on the memory tab and you'll see if you're in single or dual channel mode

 

[djforeman]

Thanks Venom,
I am running in dual channel mode. NOw, what about he add-on RAM? Do both channels have to have the same size SIMMs?

 

[PUTALE]

YES. Both sticks of ram have to be same size (ie both 512mb for 1gig of ram). It would even be nicer if both sticks are from same companies that are produced the same time which gives same timing and specs. It's not required but the same timing (or dual channel tested) memories usuaally gives less problem.

 

[djforeman]

I know that the sticks in each PAIR have to be the same size, but do the the 2 PAIRS have to be the same size? That is, can I have ONE pair = 2*256 and another pair = 2*512 for a total of 1.5GB??

 

[LipsOfVenom]

you're motherboard has 4 slots for ram...slots 1 and 3 I'll call channel 1 and slots 2 & 4 i will call channel 2...you need to match slots 1 with 3 and slots 2 with 4...but you don't need to have the same amount of RAM in all 4 slots. i.e. you can have:

1 stick of 512 MB in slot 1
1 stick of 256 MB in slot 2
1 stick of 512 MB in slot 3
1 stick of 256 MB in slot 4...

as long as the channel is matched...channel 1 does not have to be exactly the same as channel 2. you could put 1 gig sticks in channel 2 and 4 if you wanted to...that's the point. 1 matcheds 3 and 2 matches 4...

 

[PUTALE]

it depends on the mobo. You need to check your mobo to see what's the max allowed ram. You can have 4 sticks of ram (2x512 and 2x256) for a total of 1.5gig but the amd64 memory controller will run 4 sticks of ram at command rate of 2T. In additino, when you have 4 sticks of ram, you will be running at the slowest speed of the 4 sticks (of course, you can fine tune in bios).

 

[djforeman]

Thanks LipsofVenom and Putale. My mobo suports up to 4 GB, so adding 1GB to my current 1/2GB will work. The ASUS book was just a little vague about not having to match ACROSS pairs to stay in dual channel mode.