I too plan to keep my current game rig as a future retro Win7 rig. I just upgraded the main HDD the other day and installed Windows 10. Its ok for a gaming OS, but I do miss Windows 7 on it. I have to admit that 10 is a fair bit "snappier" though, so its gonna stay on there. At the end of the year, I will build a new rig and this one will become my primary work rig / backup box. I'm just gonna copy paste my Steam profile to list the hardware.
Operating System: Windows 10 Home
Motherboard: Gigabyte Technology Co., Ltd. G1.Sniper 2 (Socket 1155)
CPU: Intel Core i7 2600K @ 3.40GHz
RAM: 8.00GB Dual-Channel DDR3 @ 802MHz (11-11-11-28)
Audio: Creative X-Fi Audio Processor (WDM)
Optical Drives: ATAPI iHAS124 B
Mouse: Corsair M40
Keyboard: Razer Blackwidow
Monitor: LG 27EA33 IPS LED
Graphics: Intel HD Graphics 3000 (Gigabyte)
NVIDIA GeForce GTX 970 4GB (EVGA FTW)
Hard Drives: 1st HDD 3TB Toshiba cached with M4 64GB SSD using Intel Rapid Storage Technology
2nd HDD 1TB Hitachi
The rig is currently housed in a Cooler Master HAF-XB with 200mm top in as an intake and top 120mm rear fan also as an intake. The front is filled with a Corsair H100i with both fans exhausting. There are two 92mm fans acting as exhaust fans in the lower half of the case. Idle temps of both the CPU, Motherboard, and GPU at stock speeds are in the mid to upper 30's. At full tilt the CPU at stock hits the high 40's and lower 50's range, while the GPU hits about mid 60's. The motherboard doesn't change much.
I've OC'ed it to 4GHz with Prime running 24 hours, without issue. I keep it at its default 3.4 and use the included Gigabyte Bay Device with an honest to goodness "Turbo" button set to bump it up to 4.0GHz when I feel I need it. So far, I have only used that button for fun, as it plays everything at 1080p pretty much maxed out and when it cant, its not a CPU bottleneck, its the GPU. I consider it to have the last great oldschool motherboard that was made. None of this UEFI crap. Just old school BIOS with all white text on a beautiful blue background. This board with all of its features came from the time that 99% of all MOBO's had moved onto UEFI and Gigabyte was bound by contract to continue using the older Award BIOS. This is a feature as navigation with arrow keys is faster in a BIOS than with a mouse, IMHO. It also looks awesome with its M4 / AR-15 themed chipset cooling solution. 😄