Some GARTs may have addressing limits which can't cover all of the physical addresses which may be available to the CPU. This is an attempt to categorize chipsets.

The maximum memory is how much you can slot in. The memory controller address limit is how much address space the northbridge is decoding. So, 4 GB of address space with 4 GB slotted in will result in less than 4 GB of RAM available to the OS because a chunk of address space gets reserved for the PCI and miscellaneous apertures. The GART address limit is how much of the MC address space the GART can map to. Status is whether we need to worry about GART addressing as a result.

manufacturer chipset name maximum memory MC address limit GART address limit status
AMD 751 768MB ?? ?? good
AMD 761 2GB ?? 4GB good
AMD 762 4GB 4GB 4GB good
AMD amd64 processor ?? ?? 1024GB good
Intel 830M/MG/MP 1GB 4GB good
Intel 845G/GL 2GB 4GB good
Intel 855GM/GME 2GB 4GB good
Intel 865G/GV 4GB 4GB 4GB good
Intel 915G/GV/GL/P/PL/GL 4GB 4GB 4GB good
Intel 915GM 2GB 4GB 4GB good
Intel 945GM 4GB 4GB 4GB good
Intel G33 8GB 64GB 64GB good
Intel G35 8GB 64GB 64GB good
Intel G965 ?? 64GB 64GB good
SiS 630/730 1.5GB ?? 4GB good
VIA PLE133 1.5GB ?? ?? good
VIA ?P4M400 2GB ?? ?? ??
VIA KM266 4GB ?? ?? ??

Note: VIA's specs webpages don't agree with their product comparisons on maximum memory sizes around the PM800 series.

manufacturer graphics chipset GART address limit
ATI Rage 128 4GB
ATI R100 4GB
ATI R200 4GB