Max ram supported by FreeBSD and boot "to-ram" option

[vince66]

Hello guys !

Please, can you tell me maximum ram FreeBSD handle ?

Furthermore, I've seen that FreeBSD supports the boot live option. Can you tell me if is there a way to load it in RAM ?

Thanks in advance.

Regards.

Vincenzo.

 

[SirDice]

Please, can you tell me maximum ram FreeBSD handle ?

The maximum a CPU can handle, which today is around 16 EB.

 

[balanga]

The maximum a CPU can handle, which today is around 16 EB.

Has that been tested? ...

 

[SirDice]

I wish I could

A memtest is going to take ridiculously long though

 

[vince66]

SirDice, your reply generates another one ... sometimes, speaking of Windows systems, I heard that they can support few GB of RAM ... maximum 64 GB, and this depends on the Windows memory manager. Is it so ?
So, doesn't FreeBSD suffer of this limitation ?

Thanks in advance.

Vincenzo.

 

[SirDice]

sometimes, speaking of Windows systems, I heard that they can support few GB of RAM ... maximum 64 GB, and this depends on the Windows memory manager. Is it so ?

It depends on the (server) license.

So, doesn't FreeBSD suffer of this limitation ?

We don't have to make money selling licenses.

 

[Beastie]

Physical memory support, just like processor support, differs between editions and is only due to licensing reasons not software limitation, as mentioned by SirDice.

And it's actually 24TB for Windows Server 2016 and 2TB for Windows 10.

https://msdn.microsoft.com/en-us/library/windows/desktop/aa366778(v=vs.85).aspx

 

[Snurg]

What's funny, from your link I notice that Windows users can downgrade from 10 to 8.1 if they find 2TB too small.
With 8.1, a whopping 128 TB are permitted.
Maybe in 20 years 8.1 will be a sought-for retro WOS?

 

[vince66]

Beastie,
I've read the SirDice's reply and you confirm it. Sincerely I was thinking of a software limitation.

Thanks very much guys !

Vincenzo.

 

[reddy]

The maximum a CPU can handle, which today is around 16 EB.

Apparently the FAQ states that it is about 4To which seems relatively low to me (for example for database instances having very large datasets):

FreeBSD as an operating system generally supports as much physical memory (RAM) as the platform it is running on does.Keep in mind that different platforms have different limits for memory.
For example, amd64 platforms support up to 4TB of physical memory.

While I am nowhere near needing that much RAM in the short-term, out of curiosity I am wondering what prevents FreeBSD from supporting more RAM when windows server can support 24TB and Linux supports up to 64TB.

 

[sko]

Apparently the FAQ states that it is about 4To

No, it doesn't.

I am wondering what prevents FreeBSD from supporting more RAM

Nothing. It does support as much RAM as the platform can handle.
As is written in the FAQ you linked.

 

[reddy]

No, it doesn't.


Nothing. It does support as much RAM as the platform can handle.
As is written in the FAQ you linked.

This is a bit pedantic but fair enough, I meant for the platform amd64. Other OSes seem to be able to support more RAM on the same platform.

 

[sko]

It was probably the maximum supported amount of ram on any available amd64 system/CPU at the time that FAQ entry was written. Again: FreeBSD has *no* limitations in this regard, especially not artificial ones.