Porkey

Monero benefits WAY more from CPU threads now. After it switched algos back in November, it seems like it's mostly a CPU-based coin now.
From my poking around, it looks like it wasn't a "small" comeback. Each thread on my 8370 is able to match or exceed the hashrate of my 980 Ti.

(woo, first post)
I, too, have suffered from this dreadful PC defect for a year now. Unfortunately, I've found that it's likely just my motherboard (specifically the chipset I'm on).
But, I have done more than plenty of Googling to find a solution. Although I've not found a solution that works for me due to my garbage motherboard,
I've heard of many people solving their troubles by trying the following:
 
Solution 1: Check if your PSU is powerful enough to run all of your hardware. It's not a very helpful
suggestion, but if your PSU's 12v rail doesn't have enough amperage to run all of your
hardware, this can lead to a large number of issues. High DPC latency included.
 
You mentioned that you're running a 680; whenever I need a rough estimate of how much amperage
I need on my 12v, I normally go to MSI's list of graphics cards and power requirements:
http://forum-en.msi.com/faq/article/power-requirements-for-graphics-cards
 
The 680 is listed as consuming 38A of power on the 12v rails.
This in mind, I'd say you need a PSU with somewhere along the lines of
60A, just to be completely safe. Everyone knows, you have to
over-compensate just a little bit when it comes to power supplies.
 
Solution 2: Disabling HPET (High Precision Event Timer) in the BIOS
HPET was supposed to be a super-accurate hardware timer for programs to use
to synchronize with real time. At first I thought it would be a bad idea to disable a
high-precision system timer, but I've never heard of disabling it having negative
side effects for people who can disable it. Apparently Windows 8 doesn't even
make use of it. People who have had DPC latency issues often see big improvements
after disabling HPET, but I've also read that if it doesn't do anything after disabling it,
then it's probably better to leave it on, which makes sense to me.
 
Solution 3: Disable power saving features of your CPU in the BIOS. Things like SpeedStep, or even TurboBoost.
From what I've read this is one of the big reasons why people have advised
disabling Intel power saving features in the past. I haven't heard of newer Intel CPUs doing this
(or perhaps not until now?), but many older Intel CPUs tend to cause large DPC latency
spikes when switching between power states/frequencies. Some people have found that
disabling these features helps, some haven't.
 
Solution 4: Disable power saving functions of your GPU.
I've read that NVidia GPUs, integrated and dedicated, have caused DPC latency issues
in the past, in the same way that Intel processors have been known to cause issues.
Some people have found that they get large DPC latency spikes when their card/chip
goes from "fast/3D" clocks to "power savng/idle" clocks. I haven't done as much reading
on this as I have the other solutions, but apparently, far into the past, this was due to
PowerMizer, which managed your GPU's power states. Disabling PowerMizer would
keep your GPU at full clock speeds all the time, but it solved some peoples' DPC problems.
 
Solution 5: Disabling Hardware in Device Manager
Multiple times, I remember reading about people disabling this or that device
in Device Manager, and finding their DPC issues resolved. The most popular thing
I can remember people disabling to cure this disease is their network adapters.
Other times, I've heard that USB devices, or even USB controllers themselves
have caused DPC latency issues.
 
Solution 6: TimerResolution
As an absolute last resort, there is a little application called TimerResolution for Windows.
It's a little quite a bit complicated to explain how this program works, but what it does, is it's a tiny
program that you can set to run as frequently as your HPET timer will allow it.
Every half-millisecond, 1.5 milliseconds, or whatever your HPET limits you to, this program
will run a small execution on your CPU that keeps your CPU "awake." The execution
consumes literally no resources, and running this program seems to be the solution
that works most frequently, or so I've read.
 
All you have to do is download the appropriate version of TimerResolution for your
operating system, open it, click "Maximum" and minimize the program. Do not close
it; it has to run in the background (every X milliseconds) to keep your CPU from
"sleeping" when it's not needed. TimerResolution probably won't reduce your
DPC latency to "normal" numbers, but it a lot of people seem to report it
reducing DPC latency, sometimes by extremely large numbers.
 
 
 
 
 
Also, some links from my "notes" that may help you, or anyone who finds this thread through Google.
I would highly suggest following these links, as they will certainly contain
possible solutions that I haven't mentioned here. Some of these solutions
are regarded as taboo because they're rumored to do bad things, but
you should read about them anyway:
http://www.lucashale.com/timer-resolution/
http://www.gearbytes.com/2012/08/dpc-tweaking-guide-for-av-gaming/
https://forums.geforce.com/default/topic/743202/geforce-drivers/dpc-latency-stuttering-high-gpu-usage-the-search-for-usable-older-drivers-or-a-fix-/
http://forums.guru3d.com/showthread.php?t=384398
http://forums.guru3d.com/showthread.php?t=374210 - Read this, (I think this thread has a bunch of interesting fixes)
http://forums.guru3d.com/showthread.php?t=374210&page=17 - then read this. "disabledynamictick" tweak is apparently ill advised.
http://www.msfn.org/board/topic/140263-how-to-get-the-cause-of-high-cpu-usage-by-dpc-interrupt/
http://hardforum.com/showthread.php?t=1600122
https://forums.geforce.com/default/topic/606941/nvidia-driver-dpc-latency-input-lag/ - This, and the below link, are related to DPC issues with NV 600 series.
http://www.overclock.net/t/1388836/input-lag-in-nvidia-drivers
http://www.sevenforums.com/network-sharing/52935-network-usage-causes-high-dpc-latency.html
 
For those of you who don't know what living with high DPC latency is like, please watch these videos.


 
 
Edit - WOW this post ended up a lot longer than I thought it would be!

Remember HighLANder?
I would happily trek up a mountain with a fully decked out version of this machine if it meant I could own it.

I only like it when its a copy of one of my games without the DRM BS (or Uplay). That and when I want to try before I buy (shame demos went out of fashion-we'd have a lot less broken/shit games).