ASUS Z97-A User Manual

1-8

Chapter 1: Product introduction

You may install 1 GB, 2 GB, 4 GB, and 8 GB unbuffered non-ECC DDR3 DIMMs into the 

DIMM sockets. You can refer to the recommended memory population below.

• 

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 configuration. Any 

excess memory from the higher-sized channel is then mapped for single-channel 

operation.

• 

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. 

• 

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:

 

- 

Use a maximum of 3 GB system memory if you are using a 32-bit Windows

®

 OS.

 

- 

 Install a 64-bit Windows

®

 OS if you want to install 4GB or more on the 

motherboard.

• 

This motherboard does not support DIMMs made up of 512 Mb (64 MB) chips or less.

• 

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 2.5 Ai Tweaker menu for manual memory 

frequency adjustment.

 •  Memory modules with memory frequency higher than 2133MHz and their 

corresponding timing or the loaded XMP profile is not the JEDEC memory standard. 

The stability and compatibility of the memory modules depend on the CPU’s 

capabilities and other installed devices.

• 

For system stability, use a more efficient memory cooling system to support a full 

memory load (4 DIMMs).

• 

Visit the ASUS website at: www.asus.com for the latest QVL.