My PSU enough for 660ti SLI?

Hello, as of this moment I run a EVGA GTX 660ti FTW 3GB gpu. With my Coolermaster Silent Pro gold 600w can I run two of these cards in SLI.

Here's my spec:

4770k (OC'd 4.2GHz)

MSI Z87 GD65

Noctua NH U14S

120GB Corsair SSD

1TB HDD

Anything else just ask or visit my profile.

 

Here's the AC Input/ DC output

AC input/ DC output

And the PSU itself:

TDP is the power required to cool the component, not power it.

600W is cutting it really close, even on Haswell. I would look into a 700W unit, assuming you have an overclock on both GPUs, which would pull roughly 230W per on +12V, so around 20 Amps per, *2, that is 40 Amps at +12V for both GPUs, overestimating to 500W, with room for the CPU (80W on Haswell, ish), with some headroom for HDDs, ODDs, OCing, and such, that puts you right at 600W, which is not good for component longevity. 700W unit or 750W unit would be ideal.

Thanks for replying. Yeah was thinking I'd need a new PSU. I've been looking at the Corsair AX 760 or the 860 anyway. It wouldn't be for a while but is there any major difference between the 860i and 860? Also would it be better to get a single 780 or 780ti than get another 660ti and a PSU? Also if I were to get a 780 or 780ti then would I need more than a 600w PSU.

I would keep this PSU, it should do just fine.

Just check out the wattage that your current setup is already using and then add another graphics card wattage to the equation. 

Is there any way you can check software wise?

GPU-Z? I think. Not sure how accurate it is, never tested it.