Not all of my RAM is shown as usable

oneeyedman · 12 Oct 2016

I have a Lenovo running Windows 10 Pro. System - About said that I had 4GB of RAM installed, but only 1.88 GB usable. So I ran a Crucial.com scan and bought a compatible 8GB RAM chip. Now it says I have 8GB of RAM installed, but still only 1.88GB usable.

Following advice in the forum, I went to System Configuration - Boot - Advanced Options, and verified that Maximum Memory is not checked.

Any advice would be much appreciated.

EdTittel · 12 Oct 2016

You don't say whether you're running 32- or 64-bit Win10. You might try filling out your System Specs more completely so we can get that info without having to ask for it. The only way I can see this happening is if
(a) you're running 32-bit Win10
(b) the onboard graphics (and perhaps other stuff, like a RAM Disk?) are chewing up substantial memory overhead
What make and model of Lenovo do you have? What's your OS bittedness (32 or 64)?
If you tell us more, we'll return in kind.

I, for example, have two Lenovo laptops: an X220 Tablet with 16 GB RAM, and a T420 laptop with 16 GB RAM. Each shows 15.9 GB RAM usable, because I lose 128MB to various system overhead elements. If you like, you can grab and run CPU-Z to see how much RAM is allocated to video on your system. CPU-Z tells me that 2108 MB of that RAM is allocated to the Intel HD3000 graphics circuitry on the mobo.

Not all of my RAM is shown as usable-x220t-vram.jpg

You could do likewise, and report back!
--Ed--

oneeyedman · 13 Oct 2016

Sorry. It's Windows 10 Pro 64 bit. Part of the CPU-Z report is below; the full report is attached.

Code:

Processors Information
-------------------------------------------------------------------------


Processor 1            ID = 0
    Number of cores        4 (max 4)
    Number of threads    4 (max 4)
    Name            Intel Pentium J3710
    Codename        Braswell
    Specification        Intel(R) Pentium(R) CPU  J3710  @ 1.60GHz
    Package (platform ID)    Socket 1170 BGA (0x0)
    CPUID            6.C.4
    Extended CPUID        6.4C
    Core Stepping        
    Technology        14 nm
    Tjmax            90.0 °C
    Core Speed        1599.3 MHz
    Multiplier x Bus Speed    20.0 x 80.0 MHz
    Stock frequency        1600 MHz
    Instructions sets    MMX, SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, EM64T, VT-x, AES
    L1 Data cache        4 x 24 KBytes, 6-way set associative, 64-byte line size
    L1 Instruction cache    4 x 32 KBytes, 8-way set associative, 64-byte line size
    L2 cache        2 x 1024 KBytes, 16-way set associative, 64-byte line size
    FID/VID Control        yes




    


Chipset
-------------------------------------------------------------------------


Northbridge            Intel Braswell Host Bridge rev. 35
Southbridge            Intel Braswell LPC Bridge rev. 35
Memory Type            DDR3
Memory Size            8 GBytes
Memory Frequency        1599.3 MHz (1:20)
CAS# latency (CL)        11.0
RAS# to CAS# delay (tRCD)    11
RAS# Precharge (tRP)        11
Cycle Time (tRAS)        28
Command Rate (CR)        1T
Host Bridge            0x2280
    SBR[1:1]        0x1344C630
    SBR[1:2]        0x65C70A05
    SBR[1:3]        0x60B28205




Memory SPD
-------------------------------------------------------------------------


DIMM #                1
    SMBus address        0x50
    Memory type        DDR3
    Module format        SO-DIMM
    Manufacturer (ID)    Crucial Technology (7F7F7F7F7F9B00000000)
    Size            8192 MBytes
    Max bandwidth        PC3-12800 (800 MHz)
    Part number        CT102464BF160B.M16
    Serial number        E021D8DF
    Manufacturing date    Week 37/Year 16
    Number of banks        8
    Nominal Voltage        1.35 Volts
    EPP            no
    XMP            no
    AMP            no


DMI Physical Memory Array        
    location        Motherboard
    usage            System Memory
    correction        None
    max capacity        8192 MBytes
    max# of devices        1


DMI Memory Device        
    designation        ChannelA-DIMM0
    format            SODIMM
    type            unknown
    total width        8 bits
    data width        8 bits
    size            8192 MBytes




Graphic APIs
-------------------------------------------------------------------------


API                Intel I/O


Display Adapters
-------------------------------------------------------------------------


Display adapter 0    
    Display name        \\.\DISPLAY1
    Name            Intel(R) HD Graphics
    Board Manufacturer    Lenovo
    Memory size        1024 MB
    PCI device        bus 0 (0x0), device 2 (0x2), function 0 (0x0)
    Vendor ID        0x8086 (0x17AA)
    Model ID        0x22B1 (0x361A)
    Performance Level    0


Software
-------------------------------------------------------------------------


Windows Version            Microsoft Windows 10 (10.0) Professional 64-bit   (Build 14393) 
DirectX Version            12.0

EdTittel · 13 Oct 2016

OK, so you're losing 1 GB of RAM to the Intel HD graphics. That still leaves 5.2 GB unaccounted for. It's also fascinating that the number didn't change when upping RAM from 4 to 8 GB. Something weird is truly up. This Feb 2016 thread says that the OP opened the PC (laptop), removed the memory module, then reseated same and was then able to use all of his memory. You might want to try this, too. Others went into BIOS and made changes to make sure it sees all 8 GB. Here;'s a Tom's Hardware thread that mentions reducing memory speed as a way to get things working, along with other helpful hints.

Hope you find something helpful or useful amidst all these possible corrective strategies. If none of this works, you may want to consider taking your PC into a shop for diagnosis and repair. They might be able to find and fix something we've missed completely in these discussions.

HTH,
--Ed--