Do all 1.6a clock throttling start at the same temp ?

[hobbit]

I have a 1.6a @ 169 Mhz/1.675V, Mem ratio 4:5 Samsung 2700 DTL @2.85 V on a ASUS P4b533-V. When the temp gets to 56C the mobo start crazy beeping. I guess it's a warning that clock throttling has kicked in (verified by a sharp drop in benchmark score). I have seen of you guys quoting temp as 58-59C. SO I wonder if all chip trigger clock throttling at the same temp ? Maybe Thugsrook will have an answer