Notebook Hardware and Upgrade Questions

Product- Notebook 15-g002ax (HP 15 notebook laptop) 64bit

OS- Ubuntu 20.04.2 LTS

Memory shows- 3.3 GiB

amd processor, REV: 22CE-100

New ram added: Hynix HMT41GS6BFR8A-PB, 8192 MB @ 800MHz (SODIMM DDR3)

I used to have 4gb of default ram in bank0 [bank1 is non customer usable]

therefore i have bought 8gb of single ram. removed 4gb of default ram & connected new 8gb ram in bank0.

but if i check in system it only show 3.3gb of ram just like before. And if i check in BIOS it shows 8gb ram.

1. Can i utilize 8 gb of ram on my system ?

2. Should i go back to my old 4gb ram since they both are delivering same ram space?

command outputs:

free -h output:

Mem: 3.3Gi  used:2.3Gi   free:149Mi   shared:49Mi buff/cache:916Mi   available:781Mi

lshw -c memory output:

*-memory
description: System Memory
physical id: 10
slot: System board or motherboard
size: 8GiB
*-bank:0
description: SODIMM DDR3 Synchronous Unbuffered (Unregistered) 800 MHz (1.2 ns)
product: HMT41GS6BFR8A-PB
vendor: Hynix
physical id: 0
serial: [Personal Information Removed]
slot: Bottom
size: 8GiB
width: 64 bits
clock: 800MHz (1.2ns)
*-bank:1
description: SODIMM [empty]
product: Empty
vendor: Empty
physical id: 1
serial: Empty
slot: Top

dmidecode -t memory output:

Handle 0x0010, DMI type 16, 23 bytes
Physical Memory Array
Location: System Board Or Motherboard
Use: System Memory
Error Correction Type: None
Maximum Capacity: 8 GB
Error Information Handle: Not Provided
Number Of Devices: 2

Handle 0x0011, DMI type 17, 34 bytes
Memory Device
Array Handle: 0x0010
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 8192 MB
Form Factor: SODIMM
Set: None
Locator: Bottom
Bank Locator: CHANNEL A
Type: DDR3
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 800 MT/s
Manufacturer: Hynix
Serial Number: [Personal Information Removed]
Asset Tag: Asset Tag:
Part Number: HMT41GS6BFR8A-PB
Rank: 2
Configured Memory Speed: 800 MT/s