I'd really like to know what kind of logic your friend uses.
Third fan for the NH-D15 while using a silent case with only 2 fans. Effect -> Louder, same temps because even with only 2 fans on it the NH-D15 doesn't get enough air. If you want lower idle/low load temps get an NH-D14. If you want lower high load temps get better/more case fans and/or delid it.
Mini-ITX motherboard in a full-size ATX mid tower. Please explain.
RM650. No. Just no. There are so many things wrong with it, I'd hit the character limit listing them.
A few question:
How far do you want to overclock?
Are you willing/able to flash the BIOS without a CPU (Z87 mobos tend to have better VRMs).
Are low noise levels a priority?
Do you want to go SLI in the future?
Are there any other reasons why you'd want a mid tower?
Do you want a semi or fully modular PSU?
PCPartPicker part list / Price breakdown by merchant
CPU: Intel Core i5-4690K 3.5GHz Quad-Core Processor (£167.50 @ Amazon UK)
CPU Cooler: Noctua NH-D15 82.5 CFM CPU Cooler (£74.72 @ CCL Computers)
Motherboard: Gigabyte GA-Z87X-UD4H ATX LGA1150 Motherboard (£107.26 @ Amazon UK)
Memory: Kingston Savage 8GB (2 x 4GB) DDR3-2400 Memory (£62.99 @ CCL Computers)
Case: Fractal Design Define R5 ATX Mid Tower Case (£80.39 @ CCL Computers)
Power Supply: Corsair CSM 450W 80+ Gold Certified Semi-Modular ATX Power Supply (£43.00 @ CCL Computers)
Total: £535.86
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-12-02 08:38 GMT+0000