FreeBSD 6.0, amd64, A8N-SLI and 4gb ram

Robert Leftwich freebsd at rtl.fmailbox.com
Wed Feb 15 04:14:51 PST 2006


Steve Kargl wrote:
> 
> You don't need "option PAE" on FreeBSD-amd64.  If you have 4+GB,
> then FreeBSD-amd64 should have access to the memory. 
> 
> We need to see the top portion of your dmesg concerning the 3 GB
> versus 4 GB question.  This is a FAQ in that a small amount of
> memory is reserved for the hardware/kernel. 
> 

Here is the output of dmesg when both the s/w and h/w PAE options are disabled 
in the bios (the bios is only reporting 3gb available):

FreeBSD 6.0-RELEASE #0: Mon Jan 30 17:49:29 EST 2006
     root at black-betty:/usr/src/sys/amd64/compile/BLACKBETTY
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 4800+ (2472.16-MHz K8-class CPU)
   Origin = "AuthenticAMD"  Id = 0x20f32  Stepping = 2
 
Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT>
   Features2=0x1<SSE3>
   AMD Features=0xe2500800<SYSCALL,NX,MMX+,<b25>,LM,3DNow+,3DNow>
   Hyperthreading: 2 logical CPUs
real memory  = 3221159936 (3071 MB)
avail memory = 3106529280 (2962 MB)
ACPI APIC Table: <Nvidia AWRDACPI>
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
  cpu0 (BSP): APIC ID:  0
  cpu1 (AP): APIC ID:  1

Is this enough of the dmesg output?


Now if I enable the h/w PAE option in the bios, it reports 4gb available and 
dmesg is:

FreeBSD 6.0-RELEASE #0: Mon Jan 30 17:49:29 EST 2006
     root at black-betty:/usr/src/sys/amd64/compile/BLACKBETTY
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: AMD Athlon(tm) 64 X2 Dual Core Processor 4800+ (2472.16-MHz K8-class CPU)
   Origin = "AuthenticAMD"  Id = 0x20f32  Stepping = 2
 
Features=0x178bfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,MMX,FXSR,SSE,SSE2,HTT>
   Features2=0x1<SSE3>
   AMD Features=0xe2500800<SYSCALL,NX,MMX+,<b25>,LM,3DNow+,3DNow>
   Hyperthreading: 2 logical CPUs
real memory  = 5100273664 (4864 MB)
avail memory = 4125216768 (3934 MB)
ACPI APIC Table: <Nvidia AWRDACPI>
FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
  cpu0 (BSP): APIC ID:  0
  cpu1 (AP): APIC ID:  1

However during bootup it runs visibly slower, the DHCP lookup never completes 
and it is generally very flaky. I compared the 2 full dmesg outputs and they are 
identical apart from the real/avail memory sizes.

If I disable the h/w PAE and enable the s/w PAE, the bios again reports 4gb 
available but FreeBSD fails during startup, printing continually, 'entry of 
nVidia Mediashield metadata is NOT supported'.

Robert


More information about the freebsd-amd64 mailing list