As far as i know ACPI-support only depends on your motherboard/BIOS...older processors may not support certain power-states, but this does not apply to modern AMD processors.
Any modern motherboard will support ACPI...if your motherboard supports 333MHz FSB parts like the Sempron 2200+/2300+/2400+/2500+/2600+/2800+ it will support ACPI for sure.
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