I get hangs every ~15 minutes. Disk activity goes to 100% as reported in Win 8.1 TaskManager ("Active time") but without any apparent data transfer ("Disk transfer rate"). Usually lasts for 2-3 minutes.

Happens when exploring (perhaps on new cell load??), when speaking to an NPC, when accessing PipBoy, basically anything.

Perhaps related to an audio synch issue? - audio stops working, then a hang soon afterwards, with the audio catching up when the hang finishes.

I'm running on lowest settings, with borderless window.

Think I'm a bit below spec on CPU - i7 2.4G - but doubt that's the reason. FPS is fine outside of the hangs.

GT740M with clean install of latest drivers.

16G RAM, 24G page file. Multo free disk space.

This usually happens when you have a bottleneck which stops the data from reaching its destination.

In most situations where i have encouterd this, it is because of overheating on Either CPU, RAM, or Chipset.

And/or you will need to either override fan control with software to increase cooling..

Clean fans, and/or air intakes.

Lower room temperatures to allow more efficient cooling (blowing hot air at something hot does not cool it as effective).

Replace Fan which can produce more cooling capacity.

This is what i personally belive might be your problem.

The game is not optimized yet, for utilizing your GPU potencial, because its built for consoles with very spesific hardware in the first place.

So i'm guessing your CPU is over worked.

If you dont have a RAM cooler i'd get me one of those, they can be bought for like $12.

And general airflow through the computer should be free of dust.

The hotter your CPU becomes, the less information will it be able to proccess.

If it gets too hot, it will nearly stop completely proccessing information.

This is why i always buy a cooler which is almost twice what i need for the CPU i use.

Then i can also run it at high load with out worrying about it going stale.

But if your cooling is fine on the CPU, i'd have a look at RAM temperatures, and Chipset temperatures.

Hope this helps.

Thanks for that - I'll check it out.

Think I've fixed this, via updating BIOS, audio firmware and disk firmware.