Question

ok i have a 250w power supply and i was wondering how many 80mm fans can i put on one 4 pin cable if i buy splitters.

Technically you can have several of them on one 4pin connector, as long as it is within spec of your power supply. Having 2 connectors or 50 connectors doesn't change the fact that your power supply only provides so many watts. As far as the fans, it depends greatly on how many fans, and the power consumption of the fans themselves. Some fans only draw .05 or .25 amps which would translate into about 1 to 3 watts. But there are some high powered fans like the Deltas that will draw over 2amps which would be about 24+watts. So it varies greatly on what you want and what you are going to use. If you have any ideas on the fans you want then maybe we can go from there.

Hope I helped...good luck

If you intend to run quite a few fans, I'd recommend you buy or build yourself a fan bus. You can control as many fans as you want from one source. Check here to see if its for you.