Uh oh... will 500W be enough?

[Oneiros42]

So I finally scrimped and saved enough money and bought the parts to make an (almost) entirely new computer, and only now that they arrive tomorrow have I thought about the power supply. My plan was to keep some parts from my original computer, and one of them was the Antec Phantom 500 psu, but now I'm wondering if it will handle the new load. Here's what the new setup will be:

Motherboard: Asus P8Z68 Deluxe/Gen3
GPU: Sapphire Radeon HD 7850 OC
CPU: Intel I5 2400
RAM: 2 x 4GB DDR3-1866

I'm keeping my two 320GB SATA hard drives and it's all going in my old Antec Nine Hundred enclosure. I will NOT be overclocking.

A couple of the power calculators online have told me I should be okay based on wattage, but it's my understanding that it's the amperage that counts. I'm not sure how to calculate that, and I'm afraid I don't even know how to tell exactly what numbers I should be looking at on the Phantom specs.

So, will my current PSU cut the mustard, or should I refrain from installing the parts for another two or three months (yes it WILL take that long) until I can afford a new PSU?

 

[sonexpc]

From experience ....it should be OK.... 7850 even use less power than 6850 .... and we try couple system of 6850 with i5-2500K use Coolermaster 500W ... and almost running for 9 months.... so far so good..

 

[ko888]

For a system using a single Radeon HD 7850 graphics card AMD specifies a minimum of a 500 Watt or greater power supply. The power supply should also have a combined +12 Volt continuous current rating of 28 Amps or greater and have at least one 6-pin PCI Express supplementary power connector.

Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Continuous Amperage Available on the +12V Rail(s) is the most important factor.

The Antec Phantom Series 500W (Phantom500), with its combined +12 Volt continuous current rating of 32.5 Amps and with two 6-pin PCI Express supplementary power connectors, is sufficient to power your system configuration with a single Radeon HD 7850.

 

[Oneiros42]

Best answer selected by Oneiros42.

 

[jonwarlock]

can my vantec ion 2 520 watt handle a single 7850 with i5 3570k without overclocking?