Dell Alienware Aurora R2 (Early 2010) - Manual (Page 40)

40 CHAPTER 5: INSTALLING ADDITIONAL OR REPLACEMENT COMPONENTS
Aurora-R2
Recommended memory configuration:
Type Slots
1066 MHz and I333 MHz DDR3 Slots 1 and 2 or slots 1 — 4
To replace memory module(s):
Aurora/Aurora ALX
Recommended memory configuration:
Type Slots
1066 MHz and I333 MHz DDR3 Slots 1, 3, and 5 or slots 1 — 6
1600 MHz XMP Slots 1, 3, and 5