No not really, depending on the overclock I doubt you're pulling much over 300w at load
The vast majority of your current is the graphics card and cpu, eg the 7950 uses around 180watts under full burn in load, and around 145watts under most games
Hard drives generally top out around 20watts under heavy load (constant read/write&seek, a defrag is generally the heaviest load they come under)
An SSD in contrast uses about 2.8 to 3watts under full load.
For that setup a good 550w to 600w psu would be plenty
how about the corsair TX550M £76
http://www.scan.co.uk/products/550w-...-eps-12v-quiet
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