HAHAHA. thanks for the reply, no Proline for me then!
The IP-S500AQ3 Proline 500W Power Supply is actually made by IN WIN known more for their cheap computer cases.
It has two +12 Volt rails with each rail rated at 17 Amps individually or 28.3 Amps combined.
This power supply has only one 6-Pin PCI-E Power Connector.
Your Radeon HD 6870 graphics card will draw a maximum of 14.1 Amps under full load. This graphics card also has two 75 Watt 6-pin PCI Express power connectors that must be used to evenly distribute the DC current draw.
That Proline 500W Power Supply doesn't even meet AMD's recommendation of a power supply with two 75W 6-pin PCI Express power connectors for your HD 6870 graphics card.