Performance problems with dual channel DDR memory

[Beppe]

fedora at geniushealth.com wrote:

> Has anyone experienced performance problems when using dual channel 
> DDR memory?
>
> We are trialling an Intel 915 GAGL motherboard, using two sticks of 
> 512 DDR memory, arranged as dual channel memory. Performance drops by 
> 2 to 5 fold slower when both banks of RAM are installed. When one bank 
> is removed, performance raises back to an acceptable level.
>
> Are there any known problems with RedHat Fedora and dual channel 
> memory? Are there issues in the kernel / patches supplied, that makes 
> the system non-performant when using dual-channel memory? (Possibly 
> also linked with a hyper-threading P4 CPU?)
>
> Has anyone else got acceptable performance from using dual channel 
> memory with Linux on Fedora? (Either an alternative AMD based system, 
> or other?) We'd be very interested to hear.
>
> Our test system
>   Motherboard:   Intel 915 GAGL
>   CPU: P4 3GHz with hyperthreading
>   RAM: 2 x 512Mb DDR (and 1x512Mb for non-dual channel tests)
>   OS: Linux Redhat Fedora Core 3
>   Kernel: 2.6.9-1.667smp (standard kernel supplied by Fedora Core 3 
> install).
>
> Many thanks in advance for any advice / suggestions anyone can offer.
>
I've an Intel 915 GEV and two sticks of 512 DDR 533 MHZ memory in dual 
channel mode. Actually it seems performant even if I have never tried
with one bank but I compared it with an other system (P4 2.8GHz and 512Mb).
Pardon me, does your Audio and Network (Marvell) works?

Beppe