GA-P55A-UD3 - Upgraded memory. BIOS settings incorrect.

[SJMaye]

I decided to upgrade my memory in my old GA-P55A-UD3 with i7-860 Intel processor.  I purchased:

Crucial Ballistix Tactical Low Profile 16GB Kit (8GBx2), DDR3-1600 PC3-12800 memory kit.  Mostly because of the low profile that I needed, but also because of the memory speeds. 

Specs: DDR3 PC3-12800 • 8-8-8-24 • Unbuffered • NON-ECC • DDR3-1600 • 1.35V • 1024Meg x 64

I know nothing about memory settings.  I normally leave it on auto.  I thought in this case I would check to make sure it was being set correctly.  It was not.

What I saw in the bios was:

Memory Frequency- 1333 MHz
CAS Latency - 9
tRCD- 9
tRP- 9
tRAS- 24

Can someone help me understand Memory 101?

[Tiger]

Serial presence detect (SPD) is a standardized way to automatically access information about a computer memory module. Memory generally comes with conservative timing recommendations in the SPD. So by leaving everything on AUTO you don't get rated memory specifications you get conservative SPD settings.

Extreme Memory Profile (XMP)

A similar, Intel-developed JEDEC SPD extension for DIMMs. This uses bytes which are unallocated by JEDEC to encode higher-performance memory timings. The higher-performance memory timings are the rated specs for the memory.

XMP automatically sets DRAM Timings, DRAM Voltage, and Memory Clock to rated specifications. You can also enter these settings manually. Please note that XMP settings are by default DISABLED.

BIOS settings:
MB Intelligent Tweaker(M.I.T.)

Extreme Memory Profile (X.M.P.)
Allows the BIOS to read the SPD data on XMP memory module(s) to enhance memory performance when enabled.
Disabled Disables this function. (Default)
Profile1 Uses Profile 1 settings.
Profile2 Uses Profile 2 settings