This is yet another missing RAM post, I've tried many of the ideas on the forum without success. So I've decided for some specific guidance.
What I have done:

1. Reseated RAM
2. Installed RAM in different slot
3. reseated processor 3x
4. checked for bent pins
5. checked for good contact on bottom of processor (little dimples on LGA pads)
6. loosened heatsink
7. replaced intel twist locks with tensioning springs and backplate for heat sink
8. What seems like every BIOS combination of speed and voltages
9. Several different BIOS versions

What I get is 4 GB on boot (BIOS shows 4 GB and Memtest will try to test 6 and fail). If I let it boot to windows, I will get 6GB(3.99GB usable) anything demanding will blue screen (mixture of codes)

Any one stick/two stick combination works fine (2 GB single or 4GB dual channel). Reseating RAM will have the typical limited success for a few days, sometimes.

The only thing that will detect 6GB is when two cold boots are performed close together. Even a cold boot after accidently clicking shutdown will detect 4GB, so it doesn't seem to be temperature related. When I get 6GB in BIOS, all is good until the next restart.


Mother Board ( EVGA X58 3X SLi E-758 )
Drivers ( 1025 )
Bios ( SZ2Z )
CPU ( 920 DO ) ( 3919B012 )
CPU Cooler ( Stock )
Memory ( Corsair XMS3 TR3X6G1600C7 1600 7 7 7 20 )
PSU ( Corsair HX850W )
GPU ( XFX 5770 )
Drivers ( 10.4 )
Operating System ( Windows 7 x64 Home Premium )
Frequency Control
CPU Clock Ratio ( 20X )
CPU Host Frequency (Mhz) ( 133 )
MCH Strap ( Auto )
CPU Uncore Frequency (Mhz) ( Auto )
CPU Clock Skew ( 0 ps )
Spread Spectrum ( Disabled )
PCIE Frequency (Mhz) ( 100 )
Memory Feature
Memory Speed ( XMP )
Memory Control Setting ( Enabled )
Memory Frequency ( 2:16 )
Channel Interleave Setting ( 6 Way )
Rank Interleave Setting ( 4 Way )
Memory Low Gap ( Auto )
tCL Setting ( 7 )
tRCD Setting ( 7 )
tRP Setting ( 7 )
tRAS Setting ( 20 )
tRFC Setting ( 88 )
Command Rate ( 1t )
Voltage Control
EVGA VDroop Control ( With VDroop )
CPU VCore ( Auto - 1.2875 )
CPU VTT Voltage ( +150 )
CPU PLL VCore ( Auto – 1.8 )
DIMM Voltage ( 1.65 )
DIMM DQ Vref ( +0mV )
QPI PLL VCore ( Auto – 1.100 )
IOH VCore ( Auto - 1.1 )
IOH/ICH I/O Voltage ( Auto – 1.5 )
ICH VCore ( 1.1 )
*PWM Frequency ( 800 KHZ )
CPU Feature
Intel SpeedStep ( Enabled )
Turbo Mode Function ( Enabled )
CxE Function ( Auto )
Execute Disable Bit ( Enabled )
Virtualization Technology ( Disabled )
Intel HT Technology ( Enabled )
Active Processor Cores ( All )
QPI Control Settings ( Enabled )
QPI Link Fast Mode ( Enabled )
QPI Frequency Selection ( 4.800 GT/s )
OC Recovery ( Disabled )
PnP/PCI PCI Express
Maximum Payload Size ( 2048 )
Power Management Setup
ACPI Suspend Type ( S1 )
HPET Support ( Enabled )
HPET Mode ( 64-bit )

I hadn't seen the alcohol cleaning step before, I'll try that later. Otherwise, I have seen and done the rest of those suggestions.

Doesn't seem to be slot or module related, alcohol and a cotton swab on the RAM contacts has helped immensely, I was amazed how much crud was there.

Well my way of solving this problem is,buy different MB had all the fun Im going to trying to get this solved have been evaga for some time but this might be the end sorry to say 24 seen in boot 6.99 usable now was 16 usable.