User Guide

ASUS MAXIMUS VIII EXTREME
1-11
Chapter 1
Memory configurations
You may install 1 GB, 2 GB, 4 GB and 8 GB unbuffered and non-ECC DDR4 DIMMs into the
DIMM sockets.
• Memory module with memory frequency higher than 2133 MHz and its corresponding
timing or the loaded XMP prole is not the JEDEC memory standard. The stability and
compatibility of these memory modules depend on the CPU’s capabilities and other
installed devices.
• You may install varying memory sizes in Channel A and Channel B. The system
maps the total size of the lower-sized channel for the dual-channel conguration. Any
excess memory from the higher-sized channel is then mapped for single-channel
operation.
• Due to the memory address limitation on 32-bit Windows OS, when you install 4GB
or more memory on the motherboard, the actual usable memory for the OS can be
about 3GB or less. For effective use of memory, we recommend that you do any of the
following:
a) Use a maximum of 3GB system memory if you are using a 32-bit Windows OS.
b) Install a 64-bit Windows OS when you want to install 4GB or more on the
motherboard.
c) For more details, refer to the Microsoft
®
support site at http://support.microsoft.
com/kb/929605/en-us.
• Always install DIMMs with the same CAS latency. For optimal compatibility, we
recommend that you install memory modules of the same version or date code (D/C)
from the same vendor. Check with the retailer to get the correct memory modules.
• The default memory operation frequency is dependent on its Serial Presence Detect
(SPD), which is the standard way of accessing information from a memory module.
Under the default state, some memory modules for overclocking may operate at a
lower frequency than the vendor-marked value. To operate at the vendor-marked or at
a higher frequency, refer to section 3.5 Extreme Tweaker menu for manual memory
frequency adjustment.
• For system stability, use a more efcient memory cooling system to support a full
memory load (4 DIMMs) or overclocking condition.