First, between SATA, 4-pin molex, and 6-pin PCIe power, SATA connectors are rated for the lowest power. (The rating for 4-pin molex connectors is only slightly higher, but they tend to handle being pushed over-spec better than SATA.)
Connecting 2 risers and a drive on the same line of SATA connectors is pushing your luck, especially since some graphics cards are known to pull more power through the PCIe slot (rather than through the onboard power connectors) than the specification allows for.
That Seasonic PSU you ordered is probably going to be much better than your current one. (Corsair's CX PSUs are one of the low-end lines by CWT.) However, using that unit alone with your current rig, plus another 580 will be cutting it close for 24/7 operation, unless you underclock them by quite a bit.
i believe that something going on with power.
I read an article about pcie riser and that they should suck power from extra 6pin of the gpu.
Can you explain what you think is going on with the power?