How can I tell how much my 600W PSU has degraded?

[ChiTownSounds]

I put my current system together about 6 years ago. I have a 600W PSU in there now. I am in the process of building a NEW computer, starting with the Video Card. I'm gonna put it in my CURRENT system and move it to the new computer when it's completed. I went and did all the PSU calculators on the different sites and built my current computer to make sure it would work but each one has givin a different result... a couple flirt with that 600W number. The ASUS calculator said I was 100W UNDER! But ONE brought up the real issue of power degradation in PSU's. So I'm wondering just HOW MUCH power my PSU is putting and not just how much it is SUPPOSED to put out! Is there a way to figure it out or maybe a program that does a read out?

 

[smorizio]

with power supply's it depends on the caps and the temps the caps are rated at. cheap ones used 85 deg paste caps that last 3-4 years then start leaking the newer good brands use higher end soild caps. the other issue you have is older power supplys wont run with haswell cpu do to how low voltage haswells cpu are. most new units are digital units that can on sleep and standby give out the small voltage haswell uses. a lot of power supply vendors had to change over there units to run with haswell cpus. there are still a lot of units on the market that wont run with haswell cpus.

 

[ChiTownSounds]

Well it has lasted me this 6 years with no problems. It is a NspireGear NSP-600V2.2BF14PFC if you know anything about their quality. The ENTIRE build, in-case somebody asks is:
Card INSTALLED: GTS250
Card I'm buying: GTX 770
AMD Athlon 64 X2 6400+
2 SATA HDD's (No CD/DVD Drive)
An audio card (Doesn't need to stay but I used it when I was Dj'ing to get separate headphone audio)

I know it all works with the 250 (DUH) I just wanna make sure that when I get the 770 I can use it immediately!