Alright. Having a modular PSU is definitely helpful.
My motherboard is the Asus Z87-A. It looks like your CPU power is slightly closer to the top of the motherboard than on mine, so you should have better luck routing it through the lower rubber grommet, around the back and through the hole on the top right (when you look on the back side).
Front side / Back side (sorry, ugly pictures)
I bought this extension from amazon and you'll see in the back I have plenty of "slack length". I guess it's ~550mm + 250mm extension total length.
If not, you'll have to run the cable across the front over your GPU, which should also reach fine. I had it that way for a while, and your CPU power isn't more than 100mm away.
An AMD Radeon 7970.
Here's my full spec list if that matters.
PCPartPicker part list / Price breakdown by merchant / Benchmarks
| Type | Item | Price |
|---|---|---|
| CPU | AMD FX-8350 4.0GHz 8-Core Processor | $194.67 @ Amazon |
| CPU Cooler | Cooler Master Hyper 212 Plus 76.8 CFM Sleeve Bearing CPU Cooler | $33.99 @ Newegg |
| Motherboard | MSI 990FXA-GD80V2 ATX AM3+ Motherboard | $171.13 @ Newegg |
| Memory | Crucial Ballistix Sport 8GB (1 x 8GB) DDR3-1600 Memory | Free @ Newegg |
| Memory | Crucial Ballistix Sport 8GB (1 x 8GB) DDR3-1600 Memory | $58.99 @ Newegg |
| Storage | Seagate Barracuda 2TB 3.5" 7200RPM Internal Hard Drive | $94.32 @ Amazon |
| Video Card | Sapphire Radeon HD 7970 3GB Video Card | $289.99 @ Newegg |
| Case | Rosewill THOR V2-W ATX Full Tower Case | $155.98 @ Newegg |
| Power Supply | SeaSonic X Series 850W 80 PLUS Gold Certified ATX12V / EPS12V Power Supply | $176.98 @ Newegg |
| Optical Drive | Asus DRW-24B1ST/BLK/B/AS DVD/CD Writer | $23.98 @ Newegg |
| Other | NZXT CB-8P 250mm Individually Sleeved 8-Pin Motherboard Power Extension Premium Cable | $8.65 @ Amazon |
| Prices include shipping, taxes, and discounts when available. | ||
| Generated by PCPartPicker 2013-08-16 13:20 EDT-0400 |