Is This GPU Compatible?

[AFKNinja]

So my build is a Vostro 230 I am trying to upgrade the PC. Only problem is wether the
Gigabyte R9 270X GDDR5-2GB 2xDVI/HDMI/DP OC Graphics Card (GV-R927XOC-2GD) will fit on my Motherboard. The motherboard is a "Dell Inc 07N90W.

Link to the GPU:http://www.amazon.com/Gigabyte-GDDR5-2GB-2xDVI-Graphics-GV-R927XOC-2GD/dp/B00FONITCE/ref=sr_1_1?ie=UTF8&qid=1430704510&sr=8-1&keywords=Gigabyte+R9+270X+GDDR5-2GB+2xDVI%2FHDMI%2FDP+OC+Graphics+Card+%28GV-R927XOC-2GD%29

 

[AFKNinja]

Again, the Dell forums will have a better answer to this; (people will have tried various cards on various boards with the latest bios updates) but the dell power supply is not big enough for a 270X. You need a 500 watt power supply. Beware the 460 Dell O'E'M units.
http://www.tomshardware.co.uk/forum/id-2547993/psu-tier-list.html

I have already upgraded the PSU with a Antec 450 W would that be enough for the GPU?