VOGONS

Search

Common searches

Dual channel memory performance when not all memory is addressed

Topic actions

First post, by feipoa

Posted on 
User metadata
Rank l33t++
Rank
l33t++

I have 4 GB of memory spanned across four DDR400 modules. If I use some older, low memory AGP graphics card, all 4 GB of my system RAM is addressed. However, if I install a newer AGP graphics card, say a GF6 with 256 MB of RAM, only 3 GB of my system memory is addressed. If only 3 GB is addressed, does my system memory still run in dual channel mode? If yes, what type of performance hit, if any, is there?

Last edited by feipoa on 2015-12-12, 22:52. Edited 1 time in total.

Ultimate 486 Benchmark | Ultimate 686 Benchmark | Cyrix 5x86 Enhancements | 486 Overkill Graphics | Worlds Fastest 486

Reply 1 of 3, by stuvize

Posted on 
User metadata
Rank Member
Rank
Member

What OS are you running and is the GF6 a AGP card? the AGP aperture size can sometimes make system ram decrease in windows. I have 16gb of ram in my modern machine and dual boot with XP32 bit there is 3.27GB a ram addressable in windows and I never notice problems from lack of dual channel performance. When using a Creative sound card games with Dsound acceleration and EAX experience pops, clicks, hums and all sorts of problems if dual channel is not enabled, other things can cause this too but Creative states that dual channel memory is required for proper Dsound acceleration. I don't know of any way test it for sure but I think memory is addressed by ROWs first and COLUMNs second so data should be spread evenly across the modules regardless how much is realy addressed by the OS

Go to top of page Go to top of page
Back to General Old Hardware
Close window
Close window