We have Mikrotik on x86 server. There are also 3 BGPv4 full views and approximately 2k users behind the router.

Periodiaclly server either hangs or gets rebooted itself because out of RAM. Is it any specific way to make it see more than 2Gb of RAM?

RouterOS 6 x86 is 32-bit only.

Use CHR on KVM/VMware/HyperV for running 64-bit.

RouterOS 6 x86 is 32-bit only.

Use CHR on KVM/VMware/HyperV for running 64-bit.

32bit can handle up to 4gb of ram. why the silly recommendation of going virtual? A 32bit machine can not visualize a 64bit machine.

@OP, why leave the most important piece of information out... how much RAM is on the system

CHR supports more RAM and also will work faster in any case. The recommendation is not silly at all.

CHR supports more RAM and also will work faster in any case. The recommendation is not silly at all.

It's silly because the OP came here asking to get his current setup to work better, not asking for recommendations on upgrades. The "upgrading to a better system then it will work better" answer is kind of obvious. That's like going around and telling people the sky is blue.

Then again after dealing with your tech support, the obvious isn't so obvious to you folks.

Now that we have 64 Bit systems we have forgotten how it use to be
The 2 GB limit is a real limit for systems running 32 Bit as is a limitation from the 32 Bit address space.
https://en.wikipedia.org/wiki/2_GB_limit

So my assumption here is that PAE is not used thus limiting the memory to 2 GB
https://en.wikipedia.org/wiki/Physical_ ... _Extension

It states that Linux enables this by default if the hardware supports it. Do not have any experience x86 ROS but perhaps there is something do be done in the hardware to enable PAE support or ROS does not support PAE.

Now that we have 64 Bit systems we have forgotten how it use to be
The 2 GB limit is a real limit for systems running 32 Bit as is a limitation from the 32 Bit address space.
https://en.wikipedia.org/wiki/2_GB_limit

So my assumption here is that PAE is not used thus limiting the memory to 2 GB
https://en.wikipedia.org/wiki/Physical_ ... _Extension

It states that Linux enables this by default if the hardware supports it. Do not have any experience x86 ROS but perhaps there is something do be done in the hardware to enable PAE support or ROS does not support PAE.

PAE first came out in 1995, I find it hard to believe he is running a 20+ year old system. But since the OP doesn't know how to add pertinent information I guess we will never know.

Fits the model of only seeing 2 GB perfect and I'm not sure modern systems activate or support this.
Have seen this before, on Linux, where have had appliances where we cannot see the full 4 GB but that have always been done to PAE not enabled in the Linux as part of the appliance software.

If the hardware is more modern I would still say OP should look at CHR as much more memory can be assigned but as you say we know very little. Backup / Restore + migration becomes much more efficient as well.

And you are correct, not only did I forget I did not know of that limitation. My first pc ran Windows 3.1, and I had no knowledge what RAM even was / or how it mattered back then. I guess nibble and minesweeper just wasn't that worried about it. I don't even remember when RAM became a issue, but it was obviously after PAE.

Using CHR has other advantages, MikroTik does not need to maintain all kinds of drivers and various x86 systems. CHR Is fast, look at this here
https://stubarea51.net/2021/12/13/mikro ... g-barrier/

It's silly because the OP came here asking to get his current setup to work better, not asking for recommendations on upgrades. The "upgrading to a better system then it will work better" answer is kind of obvious. That's like going around and telling people the sky is blue.

This is not silly at all. Many do not now that you have various version that can run on x86. "I do have an x86 system" -> x86 seems to be the correct choice.
So it may be that OP did not know, and see now that he can use CHR router and get a big performance boost and become an even more happy MikroTik user