Other than to check and see whether Dell shipped that CPU with your system, there is no way to be sure.  It should work - the power requirements are similar to the slower CPUs supported by the system.

That said, CPU upgrades rarely make sense from an economic standpoint -- you won't gain much for your money as the speed difference between these two CPUs is incremental, not dramatic.

I looked Intel Processor list T8100 and T9300 both have same fsb, same socket pins&architecture ,same voltage. Differences:t8100=3mb L2 cache, t9300=6mb L2 cache, t8100=2100 Mhz frequency and t9300=2500 Mhz frequency. This upgrade will cost me average 20-25 $. t9300 has %25 more performance so iwant to upgrade.If it would be cost much for me, i wouldn't think to upgrade processor.

The CPU should work fine - but though the clock speed is 25% greater, everything else in the system will remain the same.  You may see about a 5% boost in CPU-intensive apps overall - barely perceptible except to a benchmarking utility.  If the price is that low and the supplier reliable, go for it.  DO NOT make the mistake of buying on EBay though - it is rife with remarked CPUs, engineering samples, and other non-authentic processors.

Tengo una de estas laptop y funciona con un procesador T8300 a 2,4 GHZ FSB800mhz velocidad del bus, vi en una pagina de usuarios de Dell que podria soportar 2.53GHZ FSB800mhz.   Dios le bendiga.