my mobo has 4 memory slots (dimm A1 A2, dimm B1 B2)i bought a matched pair of corsair memory and stuck them into slots A2 and B2 machine works ok.after reading the mobo book it says for dual configuration the total size of memory module installed per channel must be the same for better performance (DIMM-A1+DIMM-A2 =DIMM-B1+DIMM-B2)does this mean to run dual channel config i should have them in dimm A1 + dimm A2..i have tried putting them in these slots but the machine just beeps at me and will not boot.the memory was bought to run in dual channel config.any help would be great.iam away to read the book like i should have done in the first place...cheers

ASUS A8N SLI DELUXE SKT 939

ATHLON 64 3800+ VENICE

250gb MAXTOR DIAMONDMAX 10 SATA 16mb

1 GB CORSAIR TWIN MATCHED MEMORY

2X WINFAST 6600GT SLI GRAPHICS

NEC 3540A 16xDUAL LAYER DVD RW

PHILLIPS 8421 DVD RW

THERMALTAKE TWV 500W PURE POWER PSU

MICROSOFT WIRELESS KEYBOARD & MOUSE

WINDOWS XP PRO

The way you have it should be fine. Typically, the manuals are wrong for some reason. Check on the website. I know for my eVGA NF41, the manual has it in reverse.

If your slots are [A1 A2 B1 B2] then you want your slots to be in (A1 and B1) or (A2 and B2). They are usually color coded too.

Try the A1 and B1 slots together, see if the motherboard beeps at you. There also may be a manual setting for dual channel mode on the mobo. If it is on, the mobo won't let you use A1A2 together.

Also, if you are using 2 blades, change the memory command rate to 1T from 2T. You'll see a big difference.

thanks m8 have done what you suggested and yes much better,this is my first build any other tips would be greatfully received

ASUS A8N SLI DELUXE SKT 939

ATHLON 64 3800+ VENICE

250gb MAXTOR DIAMONDMAX 10 SATA 16mb

1 GB CORSAIR TWIN MATCHED MEMORY

2X WINFAST 6600GT SLI GRAPHICS

NEC 3540A 16xDUAL LAYER DVD RW

PHILLIPS 8421 DVD RW

THERMALTAKE TWV 500W PURE POWER PSU

MICROSOFT WIRELESS KEYBOARD & MOUSE

WINDOWS XP PRO