I have a CHIEFTEC CTG-500-80P, 500W ATX PSU and I just bought a Sapphire HD 7950 and i'm planning on getting a better psu some time soon, but what I'd like to know is if I can put the 7950 in my PC right now.
my current build:
CHIEFTEC CTG-500-80P, 500W ATX PSU
Intel Core I5 3570k@ 4.3 GHz with a cooler master hyper 212 EVO cooler
Asus P8 Z77 V motherboard
HD 5770(soon to be replaced with 7950)
2 x 2 GB DDR3 GEIL BLACK DRAGON 1600 MHz
2xHDD Western Digital 1TB
DVD-RW SAMSUNG 22X
So, can my current PSU handle this? And i'm just wondering, what would happen if i put the 7950 in and the psu couldn't handle it? Would the pc just keep restarting, would it even start and is there a chance that it may cause some damage to itself or any other component?
Your PSU unfortunately has two 12V rail, both capable of delivering 20A of current.
A 7950 draws about 140W while gaming. This means it needs about 13A.
Now, it depends on how the rails are distributed in this PSU. If one rail is entirely dedicated to power the GPU, you are good to go. This would give 13A/20A=65% of rail load. But if the rail is shared with something else, like CPU, then it won't be able to provide enough current. Furthermore, it has only one 6+2 PCI-E power connector. This means you will have to use molex->PCI-E adapters, which further complicates things.
Overloading the PSU can have many outcomes. Weak 3D performance, crashing while gaming, resets or shutdowns of the PC, freezing. In worst case PSU can explode and kill some other components.
I am guessing that it would work. Try it.
If the psu does not supply sufficient power under increased 3d gaming load, you would expect to see display artifacts. Or, a drop in fps, or possibly a shutdown. So long as the psu is not faulty, you should be ok.
I am uncertain about chieftec quality. A low quality psu can cause damage to other parts if it fails. A low quality psu will not deliver advertised power.
If you replace the psu, overprovision a bit with a 650w unit from a quality maker like Seasonic.
A stronger psu will run quieter and be more efficient. A 650w unit can support any single modern graphics card out there, including a R9-290X, or GTX780ti.