Will my core i5 750 bottleneck a GTX680?

But if you already have the Thermaltake TR2 RX 850W TRX-850M (W0319RU) ...

For a system using a single GeForce GTX 680 graphics card NVIDIA specifies a minimum of a 550 Watt or greater power supply that has a combined +12 Volt continuous current rating of 38 Amps or greater and that has at least two 6-pin PCI Express supplementary power connectors.

For a system using two GeForce GTX 680 graphics cards in 2-way SLI mode NVIDIA specifies a minimum of a 750 Watt or greater power supply that has a combined +12 Volt continuous current rating of 53 Amps or greater and that has at least four 6-pin PCI Express supplementary power connectors.

Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Total Continuous Amperage Available on the +12V Rail(s) is the most important factor.

The Thermaltake TR2 RX 850W TRX-850M (W0319RU), with its combined +12 Volt continuous current rating of 69 Amps and with two 6-pin and two (6+2)-pin PCI Express supplementary power connectors, is more than sufficient to power your system configuration with a single GeForce GTX 680. It is also sufficient to power your system configuration with two GeForce GTX 680 in 2-way SLI mode.

The problems with the Thermaltake TR2 RX 850W TRX-850M (W0319RU) arise when you draw 78% or more of its labelled power. Those cheap PSUs made by hec/compucase will exceed the electrical ripple and noise levels allowed by the ATX12V Power Supply Design specifications. Excess ripple will rapidly degrade the electrolytic capacitors on your motherboard, graphics card, PSU itself, controller locic board on disk drives, ..., etc. rendering them useless.