Question 16GB RAM (7.89) usable

tharat

Prominent
Apr 22, 2020
8
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Hi all,

I have been trying to fix the usable RAM issue for some time now and Iv'e hit a brick wall.

I currently have 16GB of DDR3 RAM but windows is only saying that 7.98GB is usable.

I have tried changing the slots and taken them all out and adding one by one and it's saying that I have half the amount in reserve.

Iv'e tried the msconfig/boot/advanced options/maximum memory. I have also updated my bios.

I booted up in safe mode and it said the exact same thing (7.89GB usable).

Motherboard: Asus M5A78L-M/USB3

Windows 64 bit

RAM:

x 1 Kingston
x1 Corsair
x2 G Skill

I have tired adding only x2 Corsair RAM and it's giving me the same problem.

nyq3mpe.jpg
 
Last edited:

Lutfij

Titan
Moderator
RAM:
x 1 Kingston
x1 Corsair
x2 G Skill


Your first mistake is mixing and matching rams. List the exact specs of each stick of ram. Second, which BIOS version are you at the moment? Which version of Windows 10 are you currently on?
 

tharat

Prominent
Apr 22, 2020
8
1
515
@Lutfij

OS: Windows 10 Home

Bios Update: Version 2101 2015/08/05

I have tried the RAM with matching sticks x 2 4GB Corsair sticks and I have the same problem.

All RAM sticks are 1600 Mhz, and the BIOS was updated to the latest version.

RAM Specs:


General Information :
DIMM0 (BANK0 ) : 4096 M
DIMM2 (BANK2 ) : 4096 M
DIMM3 (BANK3 ) : 4096 M


Information SPD EEPROM
Manufacturer : Kingston
Part Number : 99U5403-03
Serial Number : F662269E
Type : DDR3-SDRAM PC3-10
Format : UDIMM (133.35 x
Size : 4096 MB (2 ranks
Module Buffered : No
Module Registered : No
Module SLi Ready (EPP) :
Module XMP : No
Module XMP 2.0 : No
Width : 64-bit
Error Correction Capabil
Voltage : 1.50v

Prefetch Buffer : 8-bit
Manufacture : Week 29 of
Thermal Sensor : No

Heat Spreader : No

Supported Frequencies :
CAS Latency (tCL) : 6 clocks @ 45
RAS to CAS (tRCD) : 6 clocks @ 45
RAS Precharge (tRP) : 6 clocks @
Cycle Time (tRAS) : 17 clocks @ 4
Min TRC : 23 clocks @ 457.6429 MH


Information SPD EEPROM (DIMM2) :
Manufacturer : G Skill

Part Number : F3-12800CL9-4GBXL
Serial Number : 0019E5440019E374
Type : DDR3-SDRAM PC3-12800 (800
Format : UDIMM (133.35 x 15)
Size : 4096 MB (1 ranks, 8 banks
Module Buffered : No
Module Registered : No
Module SLi Ready (EPP) : No
Module XMP : Yes
Module XMP 2.0 : No
Width : 64-bit
Error Correction Capability (EC..
Voltage : 1.50v
Prefetch Buffer : 8-bit
Manufacture : 2000
Thermal Sensor : No
Heat Spreader : No

Supported Frequencies : 457.6429
CAS Latency (tCL) : 6 clocks @ 45
RAS to CAS (tRCD) : 6 clocks @ 45
RAS Precharge (tRP) : 6 clocks @
Cycle Time (tRAS) : 16 clocks @ 4
Min TRC : 22 clocks @ 457.6429 MH


XMP Profile : XMP-1600

Version : 1.2

Specification : PC3-12800

Voltage : 1.50V

Cycle Time : 1.25ns @800 MHz

RAS Precharge (tRP) : 10.88 ns

RAS to CAS (tRCD) : 10.88 ns

tWR : 15 ns

Cycle Time (tRAS) : 29.62 ns

tRC : 40.88 ns

Command Rate : 2T

Supported Frequencies : 827 MHz

CAS Latency (tCL) : 9 clocks @ 82
RAS to CAS (tRCD) : 5 clocks @ 45
RAS Precharge (tRP) : 5 clocks @
Cycle Time (tRAS) : 14 clocks @ 4
tTRC : 19 clocks @ 457.6429 MHz,


Information SPD EEPROM (DIMM3) :
Manufacturer : G Skill
Part Number : F3-12800CL9-4GBXL
Serial Number : 0019E5440019E374
Type : DDR3-SDRAM PC3-12800 (800
Format : UDIMM (133.35 x 15)
Size : 4096 MB (1 ranks, 8 banks
Module Buffered : No
Module Registered : No
Module SLi Ready (EPP) : No
Module XMP : Yes
Module XMP 2.0 : No
Width : 64-bit

Error Correction Capability (EC..
Voltage : 1.50v

Prefetch Buffer : 8-bit

Manufacture : 2000

Thermal Sensor : No

Heat Spreader : No

Supported Frequencies : 457.6429
CAS Latency (tCL) : 6 clocks @ 45
RAS to CAS (tRCD) : 6 clocks @ 45
RAS Precharge (tRP) : 6 clocks @
Cycle Time (tRAS) : 16 clocks @ 4
Min TRC : 22 clocks @ 457.6429 MH


XMP Profile : XMP-1600

Version : 1.2

Specification : PC3-12800

Voltage : 1.50V

Cycle Time : 1.25ns @800 MHz

RAS Precharge (tRP) : 10.88 ns

RAS to CAS (tRCD) : 10.88 ns

tWR : 15 ns

Cycle Time (tRAS) : 29.62 ns

tRC : 40.88 ns

Command Rate : 2T

Supported Frequencies : 827 MHz

CAS Latency (tCL) : 9 clocks @ 82
RAS to CAS (tRCD) : 5 clocks @ 45
RAS Precharge (tRP) : 5 clocks @
Cycle Time (tRAS) : 14 clocks @ 4
tTRC : 19 clocks @ 457.6429 MHz,


Memory Controller Information :
Memory Controller : System Memory
Location : Mainboard

Error Correction Capability : No
Number of connectors : 4

Max. Module Size : 16384 MB
 
Last edited:

tharat

Prominent
Apr 22, 2020
8
1
515
I have reinstalled windows and the same problem is still occurring.

I currently have x2 4GB G Skill sticks in A1 A2 and I'm getting the full 8GB. As soon as I add ANY ram into B1 B2 I get the (7.98 usable) in windows.
ZL40NKR.jpg
 
Last edited:
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