reparing memory
 

when I look in the system information my computer is only running on 2.8GB ram, but there are 4GB, how do I fix this?

Thanks

ps. I am a beginner at linux, and just started learning

Ole

Most likely you are running a 32 bit version of Linux, I would recommend to go for a 64 bit version.
Alternatively you can install a PAE kernel, but newer Mint versions should use such a kernel by default.

How did you check the RAM? Can you post output of:

I use Linux Mint 13 64 bit

I looked in system information under ram

Ole

Post output of:

MemTotal: 2824044 kB
MemFree: 1352644 kB
Buffers: 32132 kB
Cached: 738448 kB
SwapCached: 27940 kB
Active: 802112 kB
Inactive: 492888 kB
Active(anon): 458112 kB
Inactive(anon): 75944 kB
Active(file): 344000 kB
Inactive(file): 416944 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 7811068 kB
SwapFree: 7639524 kB
Dirty: 52 kB
Writeback: 0 kB
AnonPages: 501676 kB
Mapped: 102600 kB
Shmem: 9636 kB
Slab: 76132 kB
SReclaimable: 51468 kB
SUnreclaim: 24664 kB
KernelStack: 2640 kB
PageTables: 21384 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 9223088 kB
Committed_AS: 2053380 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 324176 kB
VmallocChunk: 34359411708 kB
HardwareCorrupted: 0 kB
AnonHugePages: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
DirectMap4k: 197184 kB
DirectMap2M: 2684928 kB

the other I cant copy

MemTotal is total "usable" RAM which is 2824044 KB i.e. around 2.7 GB.
MemFree is the amount of physical RAM, left unused by the system, which is 1352644 KB i.e. 1.29 GB.
Total: MemTotal + MemFree = 4176688 KB i.e. around 3.98 GB.

So in your case, the MemFree i.e. 1.29 GB is not in use, that is why you see only 2.7 or 2.8 GB of physical memory.

To find out how system calculates the free memory (see here).

Hope this helps.

thanks for your help

Ole

Not quite true. The amount that is subtracted from physical memory to give MemTotal is reserved by the kernel. I have 24 GB RAM in my system:

Some computer can't actually support 4GB, even if they have a 64 bit CPU and often even though the manufacturer claims 4GB support.

Usually that means installing 4GB gives you 3 and fraction GB usable, but it can be as low as the 2.8GB usable reported in this thread.

But some systems have a BIOS option for memory "remap" (often called other things, so it may be hard to identify). With that BIOS option enabled you can use almost all of your 4GB, but with it disabled you have much less usable.

Try to find that BIOS option on your system.

That is mostly nonsense. MemFree is included in MemTotal. Adding it in again is just wrong.

The OP have either a hardware restriction or an incorrectly set BIOS option.

Saying this is not just enough, please explain!

Read any of the similar threads. This is a common issue that has been discussed in many previous threads.

@johnsfine:
As per explaination of /proc/meminfo (on various websites):
So I don't think that MemFree is already included in MemTotal. Please read those descriptions again. (Let's say here)

Wrong, Wrong, Wrong. Total memory available is exactly what it says, total memory available. Free memory is part of that total. He has ~2.8 gig available because he has a 32-bit system board that reserves memory above that boundary for hardware addresses. This is a well-known limitation of 32-bit architecture. The fact he has a 64-bit CPU is irrelevant, in the transitional period between 32-bit and 64-bit, there were many boards with 32-bit chipsets that supported 64-bit CPUs. Yes, it sounds stupid, but it's true. The amount reserved varies, but usable memory can vary from 2.8 to 3.5 depending on how the board is configured. A lot of these boards were designed when most people didn't have more than 256 or 512, so it was never an issue.

The other possibility of defective RAM is possible, but unlikely, since when that happens you usually have an even increment, like 1024, 2048, etc, that works, while the rest doesn't.

This is what I get on a 64 bit system with 16GB of RAM:According to your explanation I would have about 25GB of RAM and that is definitely not the case.
MemTotal shows the total amount of memory available to the system.