12GB RAM only 8GB usable

I'm a newbie to posting in a forum, so I hope I give all the needed information.

Last weekend I transferred all my "parts" from one case to a new one. When I checked "System"... I noticed under Installed Memory (RAM) 12.0 GB (8.00 GB usable). I found and tried a couple ideas on the internet to try and fix this issue. I reseated the memory (no change). I tried only 6 GB at a time (all memory worked, but only with 6 GB at a time). I removed CPU and inspected pins on motherboard. As far as I could tell, none were bent. I found a little thermal paste on the edge/bottom of the CPU, so I cleaned it and the motherboard pins and reinstalled everything. I now had 12 GB of usable RAM.

I tried my first overclock yesterday and ran LinX (stable at 3.66 GHz). This morning when I was about to run Prime95, I went to "System" and again noticed under Installed Memory (RAM) 12.0 GB (8.00 GB usable). I went back into BIOS and switched back to Optimize Settings, but still only had 8 GB usable RAM.

I am quite frustrated right now. Any ideas on what I could possible do to get this working right would be greatly appreciated.
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OK... this is a little strange, but I wanted to post it because SOMEONE has to know what's going on. I read in a forum about an issue like mine to go into msconfig and make sure under Boot tab and Advanced Options that Maximum Memory WAS NOT checked. WELL...mine was not checked, but I checked it to see what affect it would have on my issue. After a restart it changed to 12 GB (11.5 GB usable). I went back in and unchecked Maximum Memory and restarted and I now have 12 Gb of memory showing and able to be used. I'm going to reset the setting in BIOS for the overclock and see what happens. Anyone know why I'm having this issue??
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I overclocked the computer back to 3.66GHz and experienced the loss of memory. I did exactly like I did in my previous post and am back to 12GB of usable RAM. I'm "assuming" it has to do with a bad setting... probably voltage, but I am stumped. Below are my overclocked settings. I am hoping someone will see this, find the problem, and help me out. If you look down on Channel C Standard and Advanced Timings... there are none.

Thanks everyone!


CPU Clock Ratio [19x]
CPU Frequency: 3.66GHz (193x19)


Advanced CPU Features [Press Enter]:
CPU Clock Ratio [19x]
CPU Frequency: 3.66GHz (193x19)
Intel(R) Turbo Boost Tech [Enabled]
CPU Cores Enabled [All]
CPU Multi-Threading [Enabled]
CPU Enhanced Halt (C1E) [Enabled]
C3/C6/C7 State Support [Disabled]
CPU Thermal Monitor [Enabled]
CPU EIST Function [Enabled]
Virtualization Technology [Enabled]
Bi-Directional PROCHOT [Enabled]
Virtualization Technology [Enabled]

QPI Link Ratio [Auto]
QPI Link Speed [6.94ghz]

Uncore & QPI Features [Press Enter]:
QPI Clock Ratio [Auto]
QPI Link Speed: 6.94ghz
Uncore Clock Ratio [x18]
Uncore Frequency 3474MHz
Isonchronous Frequency [Enabled]

Base Clock (BCLK) Control [Enabled]
BCLK Frequency (MHz) [193]

Advanced Clock Control [Press Enter]:
>>>>> Standard Clock Control
Base Clock (BCLK) Control [Enabled]
BCLK Frequency (MHz) [193]
PCI Express Frequency (MHz) [auto]
C.I.A.2 [Disabled]
>>>>> Advanced Clock Control
CPU Clock Drive [ 800mV]
PCI Express Clock Drive [ 900mV]
CPU Clock Skew [ 0ps]
IOH Clock Skew [ 0ps]

Performance Enhance [Standard]
Extreme Memory Profile (X.M.P.) [Profile1]
System Memory Multiplier (SPD) [8.0]
Memory Frequency (MHz) 1600 1544
DRAM Timing Selectable (SPD) [Auto]
Profile DDR Voltage 1.6V
Profile QPI Voltage 1.35V

Channel A
CAS Latency Time 9 [Auto]
tRCD 9 [Auto]
tRP 9 [Auto]
tRAS 24 [Auto]
Command Rate (CMD) 2 [Auto]

Channel B
CAS Latency Time 9 [Auto]
tRCD 9 [Auto]
tRP 9 [Auto]
tRAS 24 [Auto]
Command Rate (CMD) 2 [Auto]

Channel C
CAS Latency Time 9 [Auto]
tRCD - [Auto]
tRP - [Auto]
tRAS - [Auto]
Command Rate (CMD) - [Auto]

Advanced DRAM Features [Press Enter]:
Performance Enhance [Standard]
Extreme Memory Profile (X.M.P.) [Profile1]
System Memory Multiplier (SPD) [8.0]
Memory Frequency (MHz) 1600 1544
DRAM Timing Selectable (SPD) [Auto]
Profile DDR Voltage 1.6V
Profile QPI Voltage 1.35V
x Channel Interleaving 6 Auto
x Rank Interleaving 4 Auto

>>>>> Channel A
Channel A Timing Settings [Press Enter]:

>>>>> Channel A Standard Timing Control
x CAS Latency Time 9 Auto
tRCD 9 Auto
tRP 9 Auto
tRAS 24 Auto

>>>>> Channel A Advanced Timing Control
x tRC 41 Auto
x tRRD 6 Auto
x tWTR 6 Auto
x tWR 12 Auto
x tWTP 24 Auto
x tWL 8 Auto
x tRFC 88 Auto
x tRTP 6 Auto
x tFAW 30 Auto
x Command Rate (CMD) 2 Auto

>>>>> Channel A Misc Timing Control
x B2B CAS Delay - Auto
x Round Trip Latency 67 Auto

>>>>> Channel A
Channel A Turnaround Settings [Press Enter]:

>>>>> Channel A Writes Followed by Reads
x Different DIMMs 6 Auto
x Different Ranks 6 Auto
x On The Same Rank 9 Auto

>>>>> Channel A Reads Followed by Writes
x Different DIMMs 9 Auto
x Different Ranks 9 Auto
x On The Same Rank 9 Auto

>>>>> Channel A Reads Followed by Reads
x Different DIMMs 6 Auto
x Different Ranks 5 Auto
x On The Same Rank 1 Auto

>>>>> Channel A Writes Followed by Writes
x Different DIMMs 6 Auto
x Different Ranks 6 Auto
x On The Same Rank 1 Auto

>>>>> Channel B
Channel B Timing Settings [Press Enter]:

>>>>> Channel B Standard Timing Control
x CAS Latency Time 9 Auto
tRCD 9 Auto
tRP 9 Auto
tRAS 24 Auto

>>>>> Channel B Advanced Timing Control
x tRC 41 Auto
x tRRD 6 Auto
x tWTR 6 Auto
x tWR 12 Auto
x tWTP 24 Auto
x tWL 8 Auto
x tRFC 88 Auto
x tRTP 6 Auto
x tFAW 30 Auto
x Command Rate (CMD) 2 Auto

>>>>> Channel B Misc Timing Control
x B2B CAS Delay - Auto
x Round Trip Latency 70 Auto

>>>>> Channel B
Channel B Turnaround Settings [Press Enter]:

>>>>> Channel B Writes Followed by Reads
x Different DIMMs 6 Auto
x Different Ranks 6 Auto
x On The Same Rank 9 Auto

>>>>> Channel B Reads Followed by Writes
x Different DIMMs 9 Auto
x Different Ranks 9 Auto
x On The Same Rank 9 Auto

>>>>> Channel B Reads Followed by Reads
x Different DIMMs 6 Auto
x Different Ranks 5 Auto
x On The Same Rank 1 Auto

>>>>> Channel B Writes Followed by Writes
x Different DIMMs 6 Auto
x Different Ranks 6 Auto
x On The Same Rank 1 Auto

>>>>> Channel C
Channel C Timing Settings [Press Enter]:

>>>>> Channel C Standard Timing Control
x CAS Latency Time 9 Auto
tRCD - Auto
tRP - Auto
tRAS - Auto

>>>>> Channel C Advanced Timing Control
x tRC - Auto
x tRRD - Auto
x tWTR - Auto
x tWR - Auto
x tWTP - Auto
x tWL - Auto
x tRFC - Auto
x tRTP - Auto
x tFAW - Auto
x Command Rate (CMD) - Auto

>>>>> Channel C Misc Timing Control
x B2B CAS Delay - Auto
x Round Trip Latency 70 Auto

>>>>> Channel C
Channel C Turnaround Settings [Press Enter]:

>>>>> Channel C Writes Followed by Reads
x Different DIMMs 6 Auto
x Different Ranks 6 Auto
x On The Same Rank 9 Auto

>>>>> Channel C Reads Followed by Writes
x Different DIMMs 9 Auto
x Different Ranks 9 Auto
x On The Same Rank 9 Auto

>>>>> Channel B Reads Followed by Reads
x Different DIMMs 6 Auto
x Different Ranks 5 Auto
x On The Same Rank 1 Auto

>>>>> Channel B Writes Followed by Writes
x Different DIMMs 6 Auto
x Different Ranks 6 Auto
x On The Same Rank 1 Auto

Load Line Calibration [Disabled]
CPU Vcore 1.13125v [1.25000v]
QPI/VTT Voltage 1.175v [1.235v]
IOH Core 1.100v [1.240V]
DRAM Voltage 1.500v [1.600V]

Advanced Voltage Control [Press Enter]:
Load Line Calibration [Disabled]
CPU Vcore 1.13125v [1.25000v]
x Dynamic Vcore
QPI/VTT Voltage 1.175v [1.235v]
CPU PLL 1.800v [Auto]

>>> MCH/ICH
PCIE 1.500v [Auto]
QPI PLL 1.100v [Auto]
IOH Core 1.100v [1.240V]
ICH I/O 1.500v [Auto]
ICH Core 1.100v [Auto]

>>> DRAM
DRAM Voltage 1.500v [1.600V]
DRAM Termination 0.750v [Auto]
Ch-A Data VRef. 0.750v [Auto]
Ch-B Data VRef. 0.750v [Auto]
Ch-C Data VRef. 0.750v [Auto]
Ch-A Address VRef. 0.750v [Auto]
Ch-B Address VRef. 0.750v [Auto]
Ch-C Address VRef. 0.750v [Auto]


Here are the settings from CPU-Z when computer was overclocked.

Hi, JFC15

i see you ask the same Question on OC forum's
stormy13 gave you a great link with alot of info.
so i will just add my 2 cents is all..

i did some searches for you of old posts for when i was in the 12GB/OC house.. and i remember that 12GB is kind of hard to get working with a OC @ it's rated speed. but it can been done..

there is a some stuff to keep in mind though. like windows versions can limit the amount of memory you have installed. (windows Home x64 ect limit is 8GB)
like 12gb(8gb usable) its reserving 4gb for hardware, you could test each stick one at a time first in all three white slots one at a time,it should boot with just one stick in any of the white slots. if not then that slot or module is faulty.

Memtest86+ ? give that a test...

Bent CPU pin, is some times the cause, & some Gigabyte bios have also been a issue with 12GB reading correct.. also XMP ain't the best option always to use with memory. try doing all manual.

this is my bios settings as a template/guide. i have 3 bios templates i use, so this is my 3.8Ghz 12GB Rock Solid. my 4.2 is just for bragging /bench but still 29hr prime95 pass. ect haha. my ram is at 1440 with 3.8ghz. but still i see it all and am happy with what i use it for..

These are BSOD codes...
0X00000050 << Incorrect Memory Timing/Freq or Uncore Multi
0X00000124 << Incorrect QPI/Vtt Voltage (To Much/Not Enough)
0X00000101 << Not enough Vcore Voltage

CPU = Model Intel Core i7 920 D0 2.66GHz (Nehalem)
Motherboard = Gigabyte GA-EX58-UD5
BIOS Version = F9m
Ram = Corsair XMS3 12GB (6x2GB) (TR3X6G1600C8)

My MAX Prime95 Temps
3.4Ghz - 58c
3.8Ghz - 68c
4.2Ghz - 76c

Advanced CPU Features:
CPU Clock Ratio ................................ [20x]
Intel(R) Turbo Boost Tech .................. [Enabled]
CPU Cores Enabled ............................ [All]
CPU Multi Threading .......................... [Enabled]
CPU Enhanced Halt (C1E) ................... [Disabled]
C3/C6/C7 State Support .................... [Disabled]
CPU Thermal Monitor ......................... [Enabled]
CPU EIST Function ............................ [Enabled]
Virtualization Technology ................... [Enabled]
Bi-Directional PROCHOT ..................... [Enabled]


Uncore & QPI Features:
QPI Link Speed .............................. x36
Uncore Frequency .......................... [AUTO]
Isonchronous Frequency ..................[Enabled]


Standard Clock Control:
Base Clock (BCLK) Control ................ [Enabled]
BCLK Frequency (MHz) ..................... [181]
PCI Express Frequency (MHz) ........... [100]
C.I.A.2 [Disabled]

Advanced Clock Control:
CPU Clock Drive ..............................[800mV]
PCI Express Clock Drive ................... [900mV]
CPU Clock Skew ............................. [0ps]
IOH Clock Skew ............................. [0ps]


Advanced DRAM Features:
Performance Enhance ...................... [Standard]
Extreme Memory Profile (X.M.P) ......... [Disabled]
System Memory Multiplier (SPD) ........ [AUTO]
DRAM Timing Selectable (SPD) .......... [Manual]
##Channel A Standard Timing Control##
CAS Latency Time ......................9 - 9
tRCD .......................................9 - 9
tRP .........................................9 - 9
tRAS .......................................24 - 24
Command Rate (CMD) ................2

Advanced Voltage Control:

CPU
Load Line Calibration ................. [Disabled]
CPU Vcore ............................... 1.1150v - [1.2125] - ........
QPI/VTT Voltage 1.150v ............1.155v - 1.275 - ........
DRAM Voltage 1.500v .............. 1.5v - 1.55 - .......


CPU PLL 1.800v ....................... [AUTO]
MCH/ICH.............................. [AUTO]
PCIE 1.500v ...........................[AUTO]
QPI PLL 1.100v .......................[AUTO]
IOH Core 1.100v .....................[AUTO]
ICH I/O 1.500v .......................[AUTO]
ICH Core 1.1v ........................[AUTO]


here is some links..

http://forums.tweaktown.com/gigabyte...y-1333mhz.html

http://forums.tweaktown.com/gigabyte...te-64-bit.html

http://www.techpowerup.com/forums/sh...d.php?t=101832

Yea Starter & Home basic..

Here are the upper RAM limits for the different editions of Windows 7:

• Starter: 8GB
• Home Basic: 8GB
• Home Premium: 16GB
• Professional: 192GB
• Enterprise: 192GB
• Ultimate: 192GB

Remember not all computers are the same even if it's the same hardware. so it is more of a guide then anything ;/

but if you ain't done so yet check the Task manager > Resource > Memory. see if there is Ram set aside for Hardware.. like this guy had. http://www.techpowerup.com/forums/at...3&d=1250594509

Have you got a 12GB Kit or is it two 6GB kits? are they all the same model matched sticks? as that can sometimes have a effect on Ram to.

i think i got lucky as i got 2x 6GB kits none matched. 3 sticks are version 1.2 and other 3 are version1.3 but are the same make/model ect.

This issue is usually cause by a faulty dimm slot on the motherboard, or by a bent pin in the CPU socket. so i would check each stick in each slot (i know a pain) but to rule it out it could be worth the time. also have you run memtest86+? is the memory free of errors?

First- take 3 sticks of ram out, and just boot up with 6GB in tri-channel mode. See if you get all 6GB showing on boot and all 6gb usable in windows. If all 6GB works, then you know atleast those 3 slots are fine, and that will leave either 1 of the other 3 slots or a bent pin in the cpu socket.

Second- If you only get 4GB usable out of 6GB, then take all your sticks of memory out and try 1 stick, in Slot 1, Then move that stick to slot3, then slot 5. If it will boot with just 1 stick in any of those 3 slots, but when all 3 are in it is only 4GB usable, then your problem is the cpu socket. If it wont boot with one of those 3 sockets, but the will with the other 2, then you know that Dimm slot is faulty.

Third- Pull your CPU out and inspect the socket for any bent or missing pins, remount the CPU and try again. While there are no pins on the CPU, there are 1366 pins on the CPU socket side. The issue with missing system memory is a very common issue and is often resolved by simply removing and reinstalling the CPU. If one of those 1366 pins doesn't make quite the correct contact with the CPU, memory could be "missing". While the CPU is removed, check the socket for pins which are obviously damaged, dust, and foreign material. It is possible that you could get some Thermal Paste on the electrical contact side of the CPU which can also cause this issue. Having an aftermarket CPU heatsink or waterblock screwed down too tight can also cause this issue. there are many possible causes of this issue. Most causes relate to the CPU or the contact between the CPU and the motherboard.

just a Quote from some guy who posted this same problem.

"I am Seeing 12GB Ram and only 8GB usable in Windows 7 "Computer Properties"! (intermitent that BIOS would detect 8GB or 12GB).

In my case the problem was voltage / power supply output to all devices, I added a USB multi 2.5" reader to the system a couple days ago and after unpluging it PLUS tweaking BIOS, on reboot all 12 GB RAM is now usable."

"While I wasn't going to reply to this, I guess my response might help anybody else. I'd already looked around the threads provided but nothing really helped. Overall, the problem was that my CPU cooler heatsink was far too tight. Remounting the CPU cooler a few times to get the balance right fixed everything up. I wasn't aware that the CPU had such control over the RAM (again, demonstrating my lack of experience in this field)."

if i can find any more info for you i will post back later.