How strong of a power supply do I need?

Solution
For a single GPU machine a quailty 550w or 650w PSU is plenty.

The thermaltake tr2 600w, however, is NOT a high-quailty unit. Here are two good choices of PSU's in that wattage range. The Corsair CXM is a perfectly fine mid-range PSU made with quailty components. The EVGA 650 G2 is one of the best PSU's in its class.

Power Supply: Corsair CXM 550W 80+ Bronze Certified Semi-Modular ATX Power Supply ($49.99 @ Newegg)
Total: $49.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-10-22 21:35 EDT-0400

Power Supply: EVGA SuperNOVA G2 650W 80+ Gold Certified Fully-Modular ATX Power Supply ($94.99 @ SuperBiiz)
Total: $94.99
Prices...

Luminary

Admirable
For a single GPU machine a quailty 550w or 650w PSU is plenty.

The thermaltake tr2 600w, however, is NOT a high-quailty unit. Here are two good choices of PSU's in that wattage range. The Corsair CXM is a perfectly fine mid-range PSU made with quailty components. The EVGA 650 G2 is one of the best PSU's in its class.

Power Supply: Corsair CXM 550W 80+ Bronze Certified Semi-Modular ATX Power Supply ($49.99 @ Newegg)
Total: $49.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-10-22 21:35 EDT-0400

Power Supply: EVGA SuperNOVA G2 650W 80+ Gold Certified Fully-Modular ATX Power Supply ($94.99 @ SuperBiiz)
Total: $94.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-10-22 21:36 EDT-0400
 
Solution