Replicated the efficiency, this is a full stock 3870K with minimal OS tuning kicking the crap out of every other 3870K score on the board
System is using an A75-UD4H, 4x1GB SS D9JN sticks, Intel X25-M SSD and HD 6450.
Steps taken to reproduce:
Place motherboard on OBT
Install CPU, RAM and GPU
Connect all cables and peripherals
Install Windows 7 SP1 (in my case from a disc image that includes .net 4.5)
Set visual elements to max performance, power plan to max performance, disable UAC (this really shouldn't matter much...)
Install HD 6450 series GPU drivers (15.7.1 WHQL)
Download GPUPI 3.2 (NOT legacy version) from https://www.overclockers.at/news/gpupi-international-support-thread
There are slower scores out there with a UD4H so I seriously doubt it's related to the board but I have an asrock A55 board I can try if people want, more likely it's the openCL version though. This is my first time running GPUPI on this platform and I didn't do anything I wouldn't have done anyway so from this first test I'm not sure how other people are so slow.
EDIT: For my own satisfaction I threw the asrock board on the bench with the X4 631 and random ram it happened to have in it, hooked up the same OS and... 2m42s. Probably shouldn't have opened that can of worms at nearly 1am, I'll have to look into it tomorrow.
EDIT2: Speedup is on bios versions F2-F4 on the A75-UD4H. F5, which updates AGESA to 184.108.40.206, loses the speedup (1m20s to 2m16s full stock 3870K). I'm not sure what the mechanism behind it is but it's not timer, and I'd hope the work is getting done because if it's not then GPUPI 3.2 is badly broken.
EDIT3: Similar speedups happen on GPUPI 3.0.1 and 3.3.2 legacy. Screenshots in an imgur album because this post is long enough already: https://imgur.com/a/lUQee6G (by the by, what's with the hwinfo regression?)