athlon X2 4600
motherboard : gigabyte GA-M55S-S3
2 X 2GB ram
nvidia 8500 PCI-E
I have just upgraded my desktop from 1GB to 4GB (2X2GB) and added a sata drive.
I am missing 64 MB
> free -m
total used free shared buffers cached
Mem: 3961 885 3075 0 26 583
-/+ buffers/cache: 275 3685
Swap: 4102 0 4102
In dmesg it shows:-
No AGP bridge found
Node 0: aperture @ 20000000 size 32 MB
Aperture pointing to e820 RAM. Ignoring.
Your BIOS doesn’t leave a aperture memory hole
Please enable the IOMMU option in the BIOS setup
This costs you 64 MB of RAM
Mapping aperture over 65536 KB of RAM @ 20000000
PCI: MCFG area at f0000000 reserved in E820
I have a pci express card so agp shouldn’t be used ?
There is no IOMMU option in my bios…
If i add to the kernel line in grub to limit memory to 2GB I do not get the 64MB loss
As an experiment I tried the 32bit distro, I compiled a kernel with pae (up to 64GB) and I do not get the errors, I also have all my ram - i.e no loss.
Also when I use 32bit or limit the memory to 2GB in 64 bit the nvidia diver seems faster ??
I’ve tried iommu=noaperture in grub - this stops the message but I still get the loss.
Anyone any ideas - I know it is only 64MB but would like to stop the errors.