Question what cpu does support my bios, laptop

[revious]

Hi guys! i have an pretty old asus u3sg laptop and i want to upgrade the cpu (current cpu is intel core 2 duo t8300 2.4ghz)
while ago i tried to put t9600 2.80 ghz , but my bios didnt recognize it. i have tried to test it with single ram , reset bios etc. but it didnt work
Bios version: Amibios 308 (latest version)
Socket: socket pga478
Ive tried to email the asus support but i didnt understand how to write the serial number of my laptop (it was so hard lol)

 

[BFG-9000]

GM965 chipset only supports up to 800MHz FSB CPUs, so 2.6GHz T9500 is the fastest that will work, and was actually a factory option on that model ASUS.

T9600 shouldn't work because it is a 1066MHz FSB processor for GM45/PM45 chipset laptops. This is why the T9500 is way more expensive used than a T9600--because it was the fastest of all for the 800MHz laptops, while a 1066MHz laptop owner could choose the faster 3.07GHz T9900 or Extreme X9100 instead of a lowly T9600