Redneck5439 :
If you already own the i5 2400 and are looking for an upgrade by going AMD you really should go for the FX 8350 or FX 8370E over the FX 6300. The FX 6300 in gaming won't seem like much of an upgrade, rendering will be better though. I would highly recommend the FX 8370E (and you can also get a quality 970 tier 1 motherboard for around $65 now that would be killer). I have seen the FX 8370E around for $150 (all prices in US dollars, don't know exchange rater for Euros) and would offer better performance than the FX 6300, especially in rendering and is only 95W. The FX 8370E is also very overclockable (most I have worked with can hit 4.9 - 5Ghz with little problem) and would be a really good fit on one of the new 970 tier 1 motherboards (unless you are getting a much better deal on a different motherboard). At 95W the FX 8370E is also much more compatible with a larger list of motherboards than the FX 8350 or FX 8370.
while id partly agree on the 8 core comment it really all depends on what motherboard is on offer.
something with a 4+1 phase is better suited to to the 6 core fx 6300 as there is still room for overclocking,there wouldnt be with any of the 8 core chips because as soon as you hit them with voltage & clock increases the power draw increases dramatically.
If its a solid 6+2 or 8+1 phase like the 970 gaming or gigabyte ud3p then thats largely irrelevant as they'll do the job with either option,
the 6300 is though imo still a decent increase over that old low wattage i5s once pushed past the 4ghz mark .
the bonus really coming from sandy/ivy is most of those old baords are sata 2/usb2/ 1333mhz max ram speed so coming to even the relaitvely old am3+ chipset you do also gain a few more modern standards with sata 3/usb3/1866mhz ram.