PSU testing software?

Hey all. Are there any programs that can test if PSU is still providing stable power? I don't want to get a PSU tester as my unit is about 5 years old and I'd rather replace it. Just wondering if I'm coming to that point.

I feel like my gtx 760 does not hold the same overclocks as before and I'm wondering if it's PSU related. I do not think anything is wrong with my gtx 760 itself.

Thanks
 
Voltage reporting software is iffy at the best of times. I certainly don't trust it. You can get cheapo volt meters that will do what you want for about 20 bucks. Not saying they are very accurate but they work well enough.

What power supply is it? Honestly theres so many VRMs on pretty much everything that if your PSU isn't dead I doubt it will make a difference.
 
http://www.newegg.com/Product/Product.aspx?Item=N82E16817194021 This is my PSU - Enermax Infiniti 720w. I can't complain - it's been a great PSU. Crossfired my 5850s for a few years until I sold those and bought a GTX 760.

Although I could get a cheapo voltage meter, I'd rather put that $20 into another PSU. Maybe there is nothing wrong. I've noticed some driver crashing which caused me to start this post but maybe Nvidia is working out drivers for Shadow of Mordor (I mean, it did just come out).