MikroTik

Posted: **Wed Sep 28, 2022 1:42 pm**

Hello,

I have bought a second hand RB850Gx2 to play with and have as a backup device. One thing I noticed it only shows 352 MiB for total memory versus 512 MB in the spec sheet: https://mikrotik.com/product/RB850Gx2#f ... ifications

I can live with it if this is normal behavior as I will never use this much memory, but I'm worried something is faulty and may cause problems later on.

What other RB850Gx2 owners are seeing?

Thanks,
Adrian

Posted: **Mon Oct 03, 2022 3:55 am**

If it's actually showing that much memory (and it's not the amount of free memory), then there is possibly something wrong with it. If it's under warranty I would contact the seller.

Posted: **Mon Oct 03, 2022 4:10 am**

I don't know how popular these were. They were discontinued in 2018 I believe.

For ram it should show the correct amount. For disk, It could have been partitioned.

Posted: **Mon Oct 03, 2022 11:56 pm**

Mine shows 480MiB.

I could have sworn that it was 512MiB when I bought it. But I am not sure now...

It works perfectly fine nonetheless.

Posted: **Wed Jun 12, 2024 8:53 pm**

Mine shows 480MiB.

I've got two of them running 6.49.13 long-term and both of them are showing 480MiB. I was able to find screenshots of of RB850Gx2 on 6.33.3 showing 469.8MiB RAM available so it doesn't always disappear in MiB quantities divisible by two. Maybe it's just a Linux kernel quirk? On amd64 PCs running fairly modern Linux distros you're never going to see exact amount of ram to the last byte.

It works perfectly fine nonetheless.

So far my pair works fine too. I bought them used and sadly didn't take screenshots to perpetuate how much RAM was available when I booted them first time.

Posted: **Wed Jun 12, 2024 11:20 pm**

Are we talking about RAM or storage size? Both are 512MB on this model.

Consider this print from one RB5009:

/system/resource/print 
                   uptime: 6w4d7h18s
                  version: 7.14.3 (stable)
               build-time: 2024-04-17 12:47:58
         factory-software: 7.0.5
              free-memory: 857.3MiB
             total-memory: 1024.0MiB
                      cpu: ARM64
                cpu-count: 4
            cpu-frequency: 350MHz
                 cpu-load: 0%
           free-hdd-space: 482.6MiB
          total-hdd-space: 512.0MiB
  write-sect-since-reboot: 357337
         write-sect-total: 393386
               bad-blocks: 0%
        architecture-name: arm64
               board-name: RB5009UG+S+
                 platform: MikroTik

"free-memory" is how much free RAM we have
"total-memory" is how much total RAM we have
"free-hdd-space" is how much free storage space we have
"total-hdd-space" is how much total storage space we have. This one is partitioned, this is why it shows 512MiB instead of 1024MiB

Posted: **Wed Jun 12, 2024 11:55 pm**

Are we talking about RAM or storage size?

We're talking explicitely about RAM. Here's output from one of my 850s:

[ksx4system@orion] > sys reso pr
             uptime: 4h14m59s
            version: 6.49.13 (long-term)
         build-time: Apr/04/2024 09:57:52
        free-memory: 447.3MiB
       total-memory: 480.0MiB
                cpu: e500v2
          cpu-count: 2
      cpu-frequency: 533MHz
           cpu-load: 0%
     free-hdd-space: 432.9MiB
    total-hdd-space: 512.0MiB
  architecture-name: powerpc
         board-name: RB850Gx2
           platform: MikroTik

The other one reports exactly the same amout of RAM.

Posted: **Thu Jun 13, 2024 5:08 am**

We're talking explicitely about RAM. Here's output from one of my 850s:
The other one reports exactly the same amout of RAM.

It's weird this 480 MiB. The only thing that occurs me is thar some firmware/driver/BIOS uses some RAM, and keeps it from the SO. So, the router has 512MiB physically installed, but the OS can only use 480MiB. Because I can't get a reasonably combination of RAM chips that could give 480MiB. Based on the site pictures, looks like it has 4 (or 8, if using both sides of the board) memory chips. If one of them failed, we would lose either 128MiB or 64MiB - and this is assuming the router would keep working.

It would leave us with either 448MiB or 384MiB of RAM.

Wait.
OP says the router reports 352MiB of RAM. You say it reports 480MiB.

512 - 480MiB = 32MiB missing memory
512 - 128MiB (one bad chip of four?) = 384MiB.
384MiB - 32MiB (the same "missing" from yours) = 352MiB.

So. How about this? The system uses 32MiB form some hardware or firmware. This leaves the SO with 480MiB.
Looking at the pictures, looks like it has 4 memory chips. So, 128MiB each, giving us the 512MiB total.

His router lost one of the chips. Completely. And it kept working with 3 of them - just like our computers sometimes do, when we get one loose RAM module, for example.
So, his router has (3 x 128MiB) - 32MiB = 352MiB. The math works.

How about it?

Posted: **Fri Jun 14, 2024 6:24 am**

So. How about this? The system uses 32MiB form some hardware or firmware. This leaves the SO with 480MiB.
Looking at the pictures, looks like it has 4 memory chips. So, 128MiB each, giving us the 512MiB total.

This seems to be true on fully functional hardware running relatively recent version of RouterOS v6.

His router lost one of the chips. Completely. And it kept working with 3 of them - just like our computers sometimes do, when we get one loose RAM module, for example.
So, his router has (3 x 128MiB) - 32MiB = 352MiB. The math works.

I did some more research. More people reported only 352MiB of RAM available on other forums, all of them were using RouterOS v7. Is it just a weird coincidence (eg. one of four RAM chips failed for those people) or did we find a bug occuring only on this hardware? I'm probably going to try to source the third RB850Gx2 and netinstall it to 7.15.1 (or whatever will be the latest stable) to investigate further.

edit few days later:

RouterBOOT reports correct amount of RAM.

Board Info:

        Board type: 850Gx2
     Serial number: (censored)
  Firmware version: 6.49.13
     CPU frequency: 533 MHz
       Memory size: 512 MiB
         NAND size: 512 MiB
        Build time: 2024-04-04 10:00:54

MikroTik

RB850Gx2 less ram than in spec?

RB850Gx2 less ram than in spec?

Re: RB850Gx2 less ram than in spec?

Re: RB850Gx2 less ram than in spec?

Re: RB850Gx2 less ram than in spec?

Re: RB850Gx2 less ram than in spec?

Re: RB850Gx2 less ram than in spec?

Re: RB850Gx2 less ram than in spec?

Re: RB850Gx2 less ram than in spec?

Re: RB850Gx2 less ram than in spec?