Asymmetric DRAM on Ivy Bridge and later?

[BElki]

I have seen a number of current generation (Ivy Bridge and later) laptops being sold with asymmetric memory configurations. In other words, the two memory channels are not populated identically with DRAM. For example:

• 4GB in one channel and none in the second channel
• 4GB in one channel and 2GB in the second channel
• 4GB in one channel and 8GB in the second channel

Will such asymmetric configurations result in some loss of system performance?

What are the memory configuration 'rules' for maximum performance?

Thank you!

[Kevin_M_Intel]

Hi eteam,

In fact there are different ways of configuring your system memory. There will be also a difference on performance (honestly, not visible) when using single mode or multi-channel configurations.

Here you have a link where you can check more information about the memory configurations:

http://www.intel.com/support/motherboards/desktop/sb/cs-011965.htm?wapkw=(Dual+memory) http://www.intel.com/support/motherboards/desktop/sb/cs-011965.htm?wapkw=(Dual+memory)

Here is also another one:

http://www.intel.com/support/motherboards/desktop/sb/CS-034258.htm http://www.intel.com/support/motherboards/desktop/sb/CS-034258.htm

[BElki · Accepted solution]

http://www.xbitlabs.com/articles/memory/display/ivy-bridge-ddr3_2.html Here is a better answer to my question. The salient information:

"Like its predecessor, the Ivy Bridge memory controller can work in symmetry mode (when the amount, clock rate and timings of memory modules in both channels coincide) as well as in compatibility mode which is referred to as Intel Flex Memory Technology. The latter's point is in dividing the whole memory array into two parts, basing on the modules' specs: one with symmetric access mode and another with asymmetric single-channel mode. As a result, LGA1155 systems can be equipped with different memory modules without a catastrophic performance hit."

-- Bob Elkind