What power supply is this?

Solution
Though a GTX 970 will hardly stress something like that, should be alright I'd think. Though if you've been using it for a long long time I'd be concerned about the caps starting to die. I still don't know how close the 750W one is to the 600W one which was reviewed and did decent.

Fortunately his system won't overload it. The 600W one gets 840mv of ripple when overloaded, talk about frying hardware.
Its little brother the 8600EPS didn't get terrible reviews (http://www.hardwaresecrets.com/rosewill-rd600n-2sb-sl-bk-power-supply-review/). But given that design is pretty old I think the limits of what we are willing to accept in power supply quality have changed. For example the ripple on the 600w unit was almost 80mV. I would get a better unit for a brand new build.
 
Though a GTX 970 will hardly stress something like that, should be alright I'd think. Though if you've been using it for a long long time I'd be concerned about the caps starting to die. I still don't know how close the 750W one is to the 600W one which was reviewed and did decent.

Fortunately his system won't overload it. The 600W one gets 840mv of ripple when overloaded, talk about frying hardware.
 
Solution
With your system a 650W unit is overkill. A Corsair RM550x is a great unit. So is the EVGA 550 G2. But if you insist on a "650W" unit the FSP Hydro G 650 is a good option. Or the Corsair RM650x.

Units like the RM550x should be capable of handling 650W easily. The RM650x is capable of 800+W. WIth no overclocking on your system a 450W unit is ideal. With overclocking a 550W unit is more ideal for efficiency.