Here is c/p of my issues with X48-DS5 mentioned in other post:

Configuration:
- Gigabyte x48-ds5
- q6600 which works on p35-ds4 at stock voltage on 333x9
- tru 120 extreme
- 2x2gb ballistix 800mhz 4-4-4-12 2.1v
- 2x 3870x22
- pc power and cooling 750w
- vista x64
- EIST, C1E, no execute memory, TM2 disabled

Situation:
- prime95 on stock settings works fine
- 333x9 crashes in prime95 almost instant making restart, or crashes after 10 minutes if i set memory to 5-5-5-15 800mhz
- tried Kingmax 2x2gb, no help from them

Tried:
- Memory at 2.3v
- mch and fsb +0.1v
- loadline calibration settings
- cpu at 1.3v (more is not needed, set top of the post)

Thanks for any help.