Full RAM is not getting recognized

Ask Fedora
1

Hey, I have recently switched to the Fedora 42 KDE plasma desktop, and honestly, I am loving it!

My PC have a total of 4GB RAM but in my system monitor app, it only shows 3.7 GB of RAM.

Tried solution (not fixed yet!)

  1. Checked fedora version - It’s 64-Bit
  2. Already updated system using sudo dnf upgrade
  3. BIOS shows available RAM as 4GB (4096MB)
  4. Tried this old solution from Fedora. It ACTUALLY reduced RAM from 3.7 GB to 1.7 GB😅 (10.4.7. Is Your RAM Not Being Recognized?)

Kindly tell me the solution for this problem, and remember I am new to the Linux world, so please tell your solution in a detailed way (step by step) :slightly_smiling_face::folded_hands:

2

Are you just reading the “free” (available) RAM? Some of it will be in use by the operating system.

You can find the memory total in /proc/meminfo.

head -n 1 /proc/meminfo 
MemTotal:       16137688 kB

Better yet, try using the free command:

$ free
               total        used        free      shared  buff/cache   available
Mem:        16137688    10466720     4439632      137900     1706340     5670968
Swap:        8388604     2146788     6241816
2 Likes
3

Maybe the igpu has reserved it if you have integrated graphics.

1 Like
4

Kernel and igpu usually reserves some

1 Like
5

4GB (Gigabytes) is 3.7 GiB (Gigibytes) - maybe the discrepancy is the units.

6

But the system should have a power-of-two quantity of RAM.

1 Like
7

I don’t have KDE installed, so can’t check, but screenshots on the internet show KDE System Guard expressing RAM in GiB, which could explain why 4,096 MB are shown as 3.7 GiB

IMG_5059
IMG_5059750×346 85 KB

Anyway, free -h, as suggested by @glb will tell us more…

1 Like
8

First thing first thank you everyone for replying! :slightly_smiling_face:

Here are the results -

$ free
               total        used        free      shared  buff/cache   available
Mem:         3894216     1425360     1340952      197084     1554400     2468856
Swap:        3893244           0     3893244

$ head -n 1 /proc/meminfo
MemTotal:        3894216 kB
9

Is there any way to check this?

10

A RAM module (or pair of modules) sold as “4 GB” actually is 4 GiB though - i.e. it’s 4096 MiB, not 4096 denary MB. So it’s not just a matter of unit conversion.

For example, on my system I have 32 GiB total RAM (i.e. 33,554,432 KiB). When I look at different Linux tools, what I see is:

  1. free shows me a smaller amount of total memory:
               total        used        free      shared  buff/cache   available
Mem:        32774428     6822480    19301560      188708     7304132    25951948
Swap:        8388604           0     8388604
  1. head -n 1 /proc/meminfo shows the the same “total” amount:
MemTotal:       32774428 kB
  1. KDE System Monitor shows my “Total Physical Memory” as 31.3 GiB, which is what you get when you take the 32,774,428 KiB shown by free and convert it to GiB (rounded to 1 decimal place).

I think what we’re seeing here is that " The total memory as listed by free does not include memory mapped by hardware devices … nor memory used by the kernel itself."

(I don’t have an iGPU, but I still see this difference between the physical RAM I have, and the “total memory” in free and in KDE System Monitor.) So as far as I can see this is normal.

1 Like
11

Use glxinfo

[leigh@mpd-pc ~]$ glxinfo | grep -E -i 'Video memory:'
    Video memory: 4096MB
    Dedicated video memory: 4096 MB
    Currently available dedicated video memory: 2995 MB
2 Likes
12

The real question here is if you @john101 have the option and budget to upgrade your RAM to maybe 8 GB.
4GB is really not enough in modern OS’ as browsers eat that much for breakfast.

13

Yeah, but my budget does not allow it :cry:

Actually, RAM was the main reason for me switching to Linux! Because in 4GB RAM, Windows lags a lot!

14

You might consider if a more lightweight desktop environment would perform better, for example LXQT or XFCE. Also, if you have too may apps open, the Linux system may lag as well. Same goes for too many tabs open in a browser. When I was limited to 4 GB, i would not run anything else if I have a browser open, for example.

1 Like
15

When looking at above 4G decode for Intel iGPU, there’s a memory range mentioned in dmesg that when converted to something, shows how much memory is taken.

I’m not sure what the specifics are on how memory is reserved. My Intel iGPU should be 128MB, Windows WDDM has it 3GB, and there’s an odd 205MB that’s reserved somewhere :stuck_out_tongue:

Capture
Capture657×564 18.4 KB

And for some reason I had 15.42 GB on openSUSE, with 15.8 GB Windows:

495107545_1223764682451084_6597559355053742059_n
495107545_1223764682451084_6597559355053742059_n1163×778 84.3 KB

And lost .1 (somewhere to the wind I guess :stuck_out_tongue:) on Fedora 42 Xfce Pre-release:

fedora-xfcepre42-fastfetch-flightgearcut
fedora-xfcepre42-fastfetch-flightgearcut613×647 67.3 KB

As long as I have at least 15GB visible I guess it’s fine :stuck_out_tongue:

1 Like
16

Thank you brother!

1 Like
17

Hi @john101
I have a laptop with 4gb of ram which is also the maximum supported. I purposely chose fedora 41 and now 42 mate. Compared to other de it is certainly very fluid and usable

1 Like