Según dicen por aquí, hay que mirar el "Build Number" en Settings / About Phone.
http://www.needrom.com/mobile/jiayu-g3-26/
How can we check if i have S501 Chip:
You can check if you have the s501 or s500 by looking at the Builld number in Settings>About Phone.
The s501 has a stock Build number of G3N 20130223-071508
The s500 may have various other build numbers… eg G3 20121115-084708, which is stock ICS.
The way I found out was by attempting to install s500 ROMs on my s501 phone. everything works fine, except Bluetooth, Wi-fi, GPS and FM radio. Jiayu will only be manafacturing s501's from now on as the s500 has been discontinued. Having an s501 is not all bad however, as this does mean that you can be sure that you have the improved display from Taiwan and none of the early build quality issues. If Jiayu release a Jelly bean upgrade I will try porting the Cyanogenmod ROM over onto it and improving on that.