PSU enogh for the system?

[Matthew555]

I have this system:
CPU: Phenom x4 965 BE (125w)
GPU: Sapphire Radeon HD 7870 2gb (175w)
RAM: 2x2gb DDR3 1600mhz
MOBO: Asus m5a97 R2.0
PSU: HKC USP 5550 (550w psu)
SSD: 128gb kingston..(not realy a powe needer)
will the system crash at full load because my psu has 75% efficiency at full load (my brother use another hkc usp5550 for more than 6 years daily so this is a very good psu but will it be enough for the system? )

the gpu recommends min 500w psu. i already use that system and it works perfectly but im afraid of gaming yet. what if my psu is too weak and the pc burns shut down anything like that.

 

[N3rdR4ge]

There's a very low chance anything will happen to your computer other than a blue screen or shut down from insufficient power. I wouldn't be worried. Try it out. Should be enough, but depending on the rest of your system, you may be close to 550. 75 efficiency just means that the psu will create 75w per 100w pulled from the wall. It doesn't mean the psu is not outputting 550w, just that it eats more power to do it.