Memory Configurations - Asus X99-A II User Manual

Memory configurations

You may install 2 GB, 4 GB and 8 GB unbuffered and non-ECC DDR4 DIMMs into the DIMM
sockets.
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1-6
You may install varying memory sizes in Channel A, Channel B, Channel C, and
Channel D. The system maps the total size of the lower-sized channel for the dual-
channel configuration. Any excess memory from the higher-sized channel is then
mapped for single-channel operation.
According to Intel CPU spec, DIMM voltage below 1.65 V is recommended to protect
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the CPU.
Due to the memory address limitation on 32-bit Windows
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
b) Install a 64-bit Windows
motherboard.
c) For more details, refer to the Microsoft
com/kb/929605/en-us.
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 Ai Tweaker menu for manual memory
frequency adjustment.
For system stability, use a more efficient memory cooling system to support a full
memory load (8 DIMMs) or overclocking condition.
Always install the DIMMS with the same CAS Latency. For an optimum compatibility,
we recommend that you install memory modules of the same version or data code
(D/C) from the same vendor. Check with the vendor to get the correct memory
modules.
The design of the DIMM fan may vary. Ensure that the DIMM fan fits to the
motherboard.
OS when you want to install 4 GB or more on the
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support site at http://support.microsoft.
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Chapter 1: Product Introduction
OS, when you install 4GB
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OS.
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