[CentOS] 4gb ram shows as 3.3gb

[Clint Dilks]

Martin Marques wrote:
> Nick wrote:
>> Hi,
>>
>> Running Centos 5 (32bit)... running a server with 4gb of RAM and it's 
>> shows up as:
>>
>> [root at ubercore1 ~]# free
>>             total       used       free     shared    buffers     cached
>> Mem:       3369544    2549668     819876          0      29008    
>> 2382360
>> -/+ buffers/cache:     138300    3231244
>> Swap:      6291448          0    6291448
>>
>> I know 4gb is the limit for a 32bit OS but i thought it would be able 
>> to use all of it? Is there another kernel i was supposed to install?
>
> The thing is, and I'm still trying to find a solution for one of our 
> servers, the the memory addresses from 4Gb down are used for PCI, VGA, 
> onboard stuff, and even though the memory isn't used, the addresses 
> are, and so they are not passed to the OS.
>
> Can you send some info on the motherboard you have?
>
Hi :)

Try passing agp=off to the kernel.  If AGP is not required.