Originally Posted by BeacoN
Any ideas to what's wrong?
Either you are not using a PAE kernel, or you have a BIOS setting wrong.
If you aren't using a PAE kernel, the easiest solution is to switch to one. Reinstalling the 64-bit build of your distribution might
be better, but it is certainly harder.
If you have a BIOS setting wrong, a 64 bit Linux would make no difference. For either PAE or 64 bit to see the memory, you need the BIOS to map the memory correctly.
So first find out if it is a BIOS problem. If it hasn't been so long since the last boot that the dmesg log has overflowed, you can find the physical RAM map by
On one of my systems, it looks like this.
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 00000000000a0000 (usable)
BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000bfe8ac00 (usable)
BIOS-e820: 00000000bfe8ac00 - 00000000bfe8cc00 (ACPI NVS)
BIOS-e820: 00000000bfe8cc00 - 00000000bfe8ec00 (ACPI data)
BIOS-e820: 00000000bfe8ec00 - 00000000c0000000 (reserved)
BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved)
BIOS-e820: 00000000fec00000 - 00000000fed00400 (reserved)
BIOS-e820: 00000000fed20000 - 00000000feda0000 (reserved)
BIOS-e820: 00000000fee00000 - 00000000fef00000 (reserved)
BIOS-e820: 00000000ffb00000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 00000001fc000000 (usable)
Notice the last line of mine. It shows the ram mapped above 4GB (0000000100000000 represents 4GB). If you have no ram mapped above 4GB, the BIOS has some setting incorrect and no OS can use more than 3 point something GB of ram.
Originally Posted by BeacoN
A guy at the Micro Center told me 32bit operating systems can have up to 32 or 64 gigs of RAM, apparently he was wrong. (it's okay, I still love you Micro Center!).
The guy at Micro Center got that right (very impressive. That's way beyond the knowledge you would expect for someone working in a computer store.)
I expect your existing distribution has a package for a PAE kernel you can download and install. Doing so would be much simpler than reinstalling the whole distribution.
I am downloading 64 bit debian and centos as I type, what 64 bit version would you suggest?
In your other thread, someone said Mint has 64 bit (it's been long enough since I tried Mint, I wasn't sure, but I think the Mint I tried was 64 bit). So why are you switching from Mint?
Anyway, Centos would be a poor choice. Stick with some Debian based distribution (Mint, or Mepis, or Ubuntu or Debian itself).
Originally Posted by lazlow
It all depends on how it fits you. That being said, I use Centos 64bit (32bit on older machines). There is certainly nothing wrong with Debian either.
Once a beginner is used to Mint, switching to a distribution in the Red Hat family would have lots of confusing differences for no benefit.
Even more significant, Centos is a server distribution. I've installed Centos a few times and I use it at work. Its install process very much assumes you are setting up an enterprise server rather than a home system.
An experience Linux user can blast right past the Debian vs. Red Hat differences and past any assumptions made by the installer, and configure almost any Linux distribution into whatever he wants.
But a beginner is just going to follow the flow laid out by whoever put together the distribution and would get totally lost trying to reach a Home Linux system from the Centos installer.