Usable Memory Triggered by Reboot

I have a Intel Core i7 920 with 12GB (6x2GB) of Corsair Triple Channel RAM mounted on an EVGA X58 motherboard. I recently noticed that my usable memory was not always synonymous with the amount installed i.e. 12.0 GB (7.99 usable), 12.0 GB (3.99 usable) etc. I've read a lot about this issue and there seem to be several different causes and solutions.

I found after dozens of boots when my computer has been powered down for an extended period of time the usable memory is always lower than the actual installed. However, if I power down and reboot after the computer has had a bit of warmup time the actual memory and usable are the same.

NOTE: Restarting will not cause this effect. Only a complete shutdown and reboot does this.

To date 11/4/2012 I have:

1.) Removed the memory and installed individually to test for bad rail or bad memory stick

2.) Cleaned each stick of memory three times with alcohol solution

3.) Updated all Hardware and BIOS

4.) Slammed my head against the desk once or twice

Any suggestions would be appreciated. I can provide more information as needed.
4 answers Last reply
More about usable memory triggered reboot
  1. What's the memory model?
  2. I see CM3X2G1333C9 on CPU-Z as a part number.

    DIMM # 1
    SMBus address 0x50
    Memory type DDR3
    Module format UDIMM
    Manufacturer (ID) Corsair (7F7F9E0000000000)
    Size 2048 MBytes
    Max bandwidth PC3-10700H (667 MHz)
    Part number CM3X2G1333C9
    Number of banks 8
    Nominal Voltage 1.50 Volts
    EPP no
    XMP no
    AMP no
    JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
    JEDEC #1 6.0-6-6-16-23 @ 444 MHz
    JEDEC #2 7.0-7-7-19-27 @ 518 MHz
    JEDEC #3 8.0-8-8-22-30 @ 592 MHz
    JEDEC #4 9.0-9-9-24-34 @ 666 MHz

    DIMM # 2
    SMBus address 0x51
    Memory type DDR3
    Module format UDIMM
    Manufacturer (ID) Corsair (7F7F9E0000000000)
    Size 2048 MBytes
    Max bandwidth PC3-10700H (667 MHz)
    Part number CM3X2G1333C9
    Number of banks 8
    Nominal Voltage 1.50 Volts
    EPP no
    XMP no
    AMP no
    JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
    JEDEC #1 6.0-6-6-16-23 @ 444 MHz
    JEDEC #2 7.0-7-7-19-27 @ 518 MHz
    JEDEC #3 8.0-8-8-22-30 @ 592 MHz
    JEDEC #4 9.0-9-9-24-34 @ 666 MHz

    DIMM # 3
    SMBus address 0x52
    Memory type DDR3
    Module format UDIMM
    Manufacturer (ID) Corsair (7F7F9E0000000000)
    Size 2048 MBytes
    Max bandwidth PC3-10700H (667 MHz)
    Part number CM3X2G1333C9
    Number of banks 8
    Nominal Voltage 1.50 Volts
    EPP no
    XMP no
    AMP no
    JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
    JEDEC #1 6.0-6-6-16-23 @ 444 MHz
    JEDEC #2 7.0-7-7-19-27 @ 518 MHz
    JEDEC #3 8.0-8-8-22-30 @ 592 MHz
    JEDEC #4 9.0-9-9-24-34 @ 666 MHz

    DIMM # 4
    SMBus address 0x53
    Memory type DDR3
    Module format UDIMM
    Manufacturer (ID) Corsair (7F7F9E0000000000)
    Size 2048 MBytes
    Max bandwidth PC3-10700H (667 MHz)
    Part number CM3X2G1333C9
    Number of banks 8
    Nominal Voltage 1.50 Volts
    EPP no
    XMP no
    AMP no
    JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
    JEDEC #1 6.0-6-6-16-23 @ 444 MHz
    JEDEC #2 7.0-7-7-19-27 @ 518 MHz
    JEDEC #3 8.0-8-8-22-30 @ 592 MHz
    JEDEC #4 9.0-9-9-24-34 @ 666 MHz

    DIMM # 5
    SMBus address 0x54
    Memory type DDR3
    Module format UDIMM
    Manufacturer (ID) Corsair (7F7F9E0000000000)
    Size 2048 MBytes
    Max bandwidth PC3-10700H (667 MHz)
    Part number CM3X2G1333C9
    Number of banks 8
    Nominal Voltage 1.50 Volts
    EPP no
    XMP no
    AMP no
    JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
    JEDEC #1 6.0-6-6-16-23 @ 444 MHz
    JEDEC #2 7.0-7-7-19-27 @ 518 MHz
    JEDEC #3 8.0-8-8-22-30 @ 592 MHz
    JEDEC #4 9.0-9-9-24-34 @ 666 MHz

    DIMM # 6
    SMBus address 0x55
    Memory type DDR3
    Module format UDIMM
    Manufacturer (ID) Corsair (7F7F9E0000000000)
    Size 2048 MBytes
    Max bandwidth PC3-10700H (667 MHz)
    Part number CM3X2G1333C9
    Number of banks 8
    Nominal Voltage 1.50 Volts
    EPP no
    XMP no
    AMP no
    JEDEC timings table CL-tRCD-tRP-tRAS-tRC @ frequency
    JEDEC #1 6.0-6-6-16-23 @ 444 MHz
    JEDEC #2 7.0-7-7-19-27 @ 518 MHz
    JEDEC #3 8.0-8-8-22-30 @ 592 MHz
    JEDEC #4 9.0-9-9-24-34 @ 666 MHz
  3. A simple solution would be buying a compatible 3 RAMs kit of 12 GB.
    You can also try manually lowering the speed in BIOS ( use JEDEC 3 settings for example).
  4. Care to elaborate for the less than technically inclined?
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