I just bought a new computer. I've got a Gigabyte P55A-UD4 motherboard, an Intel i5 750 CPU and Kingston HyperX 4G memory which can run at 1600 MHz with XMP enabled but runs at 1333 MHz otherwise. If I try to enable XMP by setting it to Profile 1 in the BIOS, the computer freezes during POST and won't boot. I've updated my BIOS to the latest version but that didn't help. Here are my RAM settings before and after enabling XMP:

Code:
XMP Disabled:
System Memory Multiplier (SPD):  Auto
Frequency: 1333 1333
Performance Enhance: Turbo
DRAM timing selectable (SPD): Auto
Profile DDR Voltage: 1.5 V
Profile QPI Voltage: 1.1 V
x Channel Interleaving: 6 Auto
x Rank Interleaving: 4 Auto

XMP Enabled:
System Memory Multiplier (SPD):  Auto
Frequency: 1600 1600
Performance Enhance: Turbo
DRAM timing selectable (SPD): Auto
Profile DDR Voltage: 1.65 V
Profile QPI Voltage: 1.3 V
x Channel Interleaving: 6 Auto
x Rank Interleaving: 4 Auto

Channel A Timings:
          XMP Disabled    XMP Enabled
CAS Latency Time:    9              8
tRCD:                9              8
tRP:                 9              8
tRAS:               24             20

tRC:                33             36
tRRD:                4              5
tWTR:                5              6
tWR:                10             12
tWTP:               21             24
tWL:                 7              8
tRFC:               74             88
tRTP:                5              6
tFAW:               20             24
Command Rate (CMD):  1              1

B2B CAS Delay:       -              -
Round Trip Latency: 46              46

Channel B is the same but round trip latency is 48.

System Memory Multipler Options:
6.0, 8.0, 10.0
Performance Enhance Options:
Standard, Turbo, Extreme
Thanks,
Adam