How much power is necessary for this build?

[astralsolace]

I'm trying to put together a new PC, and trying to save as much of my old equipment as possible. How much power would you say is necessary for this build?:

CPU:Intel Core i7-3770K Ivy Bridge 3.5GHz (3.9GHz Turbo) LGA 1155 77W Quad-Core Desktop Processor Intel HD Graphics 4000 BX80637I73770K
MOBO: ASRock Z77 OC Formula LGA 1155 Intel Z77 HDMI SATA 6Gb/s USB 3.0 Extended ATX Intel Motherboard
RAM: Kingston HyperX XMP 10th Anniversary Series 16GB (4 x 4GB) 240-Pin DDR3 SDRAM DDR3 2400 (PC3 19200) Desktop Memory Model KHX24C11X3K4/16X
Case: Antec P280 Black ATX Mid Tower Computer Case
Cooling Cooler Master Hyper 212 EVO - CPU Cooler with 120mm PWM Fan (RR-212E-20PK-R2)
GPU (re-used from old PC) XFX ATI Radeon HD 5870 1 GB DDR5 PCI-Express Card HD587AZNF9
SSD (re-used from old PC) Intel 2.5-Inch 160 GB X25-M Mainstream SATA II MLC Solid-State Drive - Retail Package SSDSA2MH160G2R5
Sound (re-used from old PC) HT | OMEGA STRIKER 7.1 Channels PCI Interface Sound Card

My old PSU is a Corsair VX-550W unit. I'm guessing that wouldn't be enough, especially if I want to overclock the CPU. Any advice would be greatly appreciated--Thanks!

 

[Lonyo]

It should be more than enough, assuming it's not massively old, even with overclocking.
It's unlikely to pull more than 400w typical load even when overclocked, assuming you aren't going for extreme overclocking with exotic cooling.

 

[astralsolace]

Awesome. Thanks--much appreciated.

 

[lehtv]

3770K = 70W at stock, 90-100W OC'd
5870 = 160W at stock, up to 200W OC'd
The rest = maybe 70W

You're going to use about 300 watts peak at full system load, 350W overclocked. When gaming, 250 watts is more like it.