Windows 10: Installed Memory in 8GB in Bios but shows as 4.9 or 5.1/5GB as Usable

Hello, this is a weird issue that I couldn't find anyone else having. Sometimes it shows as 4.9GB, other times as 5GB or 5.1GB. 6GB. Here are my specs:Inspiron 15 5570Windows 10 22H2 latest versionIntel Core i78GB RAM4GB AMD Radeon 530Intel 650 UHDI checked my BIOS, and it showed 8GB as the installed memory. After that, I loaded into Windows and checked dxdiag to see the size of my dedicated graphics card. It showed as 8GB for some reason, but on Task Manager, dedicated graphics card size showed as 4GB I don't know if that is the issue.also sometimes processor speed also gets capped to 0.39

:)

 

Windows 7 SP 1 32-bit shows installed memory: 8GB (3.78 usable). Why is it showing so?

Windows 7 SP 1 32bit shows installed memory: 8GB(3.78 usable). why is it showing so?

* Moved from Garage

* Original title: usable memory

 

Installed memory: 8GB (6GB usable) - 2 GB is Hardware Reserved

I have a 64-bit windows 10 desktop with 4GB (2x2GB) of memory that I built about nine years ago. A week ago I purchased more memory (2x2GB) of the same brand/model/specs to bring the total up to 8GB but when I installed it, windows said 8GB is installed but only 4GB is usable. Furthermore, bios only recognized the 4GB. I removed the two new ones memory sticks that I purchased and went back to 4GB I originally had and Windows then said 4GB installed and only 2GB usable. The bios also recognized only 2GB. I tried reseating the DIMMS with several combinations and it now says 8GB installed with 6GB usable (again, BIOS only recognizes 6GB). So each time BIOS is only recognizing what Windows says is usable, not what Windows says is installed. I have a dedicated GPU. Resource Monitor shows 2GB is "hardware reserved". I'd for all 8GB to be usable, not just the 6GB.

Heres what I've tried so far:
1. msconfig memory limits is unchecked.
2. a fresh install of Windows
3. reflashed BIOS (I was already on the latest version)
4. Ran "Speccy" software and it reads all four DIMMS
5. Checked for any RAM management settings in BIOS but there are none. Motherboard manual URL below http://download1.gigabyte.us/Files/M...x58-ud3r_e.pdf
6. All DIMMS have been tested individually and work fine.
7. Ran Memtest86 for 23 hours and it produced zero errors.
8. Tried both fail-safe and opimized default settings in BIOS.
There are other things I tried that I can't think of off the top of my head. Any thoughts/input would be great.

Components:
https://www.newegg.com/Product/Produ...82E16813128375
https://www.newegg.com/Product/Produ...0666CL9D-4GBNQ

Specs:
Operating System
Windows 10 Pro 64-bit
CPU
Intel Core i7 920 @ 2.67GHz 65 °C
Bloomfield 45nm Technology
RAM
8.00GB Dual-Channel DDR3 @ 532MHz (8-8-8-20)
Motherboard
Gigabyte Technology Co. Ltd. EX58-UD3R (Socket 1366) 35 °C
Graphics
SyncMaster (L: [email protected])
512MB NVIDIA GeForce 9500 GT (EVGA) 60 °C
Storage
111GB Crucial_CT120M500SSD1 (SSD)
298GB Western Digital WDC WD3200AAKS-00L9A0 (SATA) 33 °C
Optical Drives
HL-DT-ST CDRW/DVD GCC4482 ATA Device
Audio
Realtek High Definition Audio

 

Installed memory: 8GB (6GB usable) - 2 GB is Hardware Reserved

This configuration just indicates slot to be used, if running dual or 3 channel. Single stick run as single. At the bottom it's saying one stick goes into 1st slot.

Motherboard could be a problem. Load optimized defaults again, or even reflash the latest BIOS. Check CPU again (I know you did) - some of CPU's pins are controlling the memory.

Edit: take care, that slot 3 and 4 are populated with same memory sticks. You said you bought same type, but they are different. No chance you're gonna get the same chips after 4 or 5 years.