On Tue August 26 2008 10:52:21 am Roger Heflin wrote:
Don't count on that, the 4GB thing is a very very rough and often wrong *SIMPLE* rule.
Just because a machine has under 4GB of ram does not mean that the PAE kernel won't give you more memory. The bios *CAN* (some do, some don't) remap something that is covered by a video card, or otherwise reserved for something to above 4GB requiring a PAE kernel to use it. And this can start happening at around 3GB of ram or more, the only way to know if PAE is correct for a given setup is to either know exactly what the bios is doing or to test it.
It all depends on exactly what the bios is doing, he would need to boot a PAE and a non-PAE kernel and check how much memory is being seen by each, if they are the same or really close (within 100MB) I would avoid the PAE kernel.
Interesting... I'll make this a keeper and test soon. I build most of my machines with 4GB of ram now, but that's in Windows land at work - they tend to filter my way as older ones are superceded or retired - my current Linux machines all top out at 3GB