Two weeks ago I upgraded my single GTX 680 Classified card to two GTX 970 4GB cards and the performance boost was amazing! And for about 1-1/2 weeks I played with EVERYTHING maxed out on Ultra @1080p 120Hz and DAI ran smooth as silk!
 
On Sunday I re-installed my OS (W8.1 64bit) and after fully updating my OS and installing Nvidia driver 344.75 I am experiencing consistent stuttering when playing DAI. My FPS stays around 120 for the most part, but every 15-20sec the game briefly, for like 2 seconds it dips to 40-50fps and visually stutters before resuming a smooth 120fps. DAI is up-to-date with the latest patch from Origin. I tried turning my V-sync off and my AA multi-sampling to X2 and off but it didn't make a difference.
 
The only thing that has changed since I re-installed my OS is my HDD setup. Before I had two 1TB Western Digital 7200rpm drives setup in Raid0, but before I re-installed my OS, I added a Seagate 1TB 7200rpm drive to my Raid0 array. And my seq read/write has actually gone down by a bit with three drives in my Raid0. Before I had 336MB/s seq read and 308MB/s seq write, now I have 299MB/s seq read and 253MB/s seq write.
 
System Specs:
i7-2600 (not oc'd)
16GB 2133Mhz Ram
Asus P8P67 Deluxe MB
x2 EVGA GTX 970 4GB in SLI mode
x3 1TB 7200rpm HDD in Raid0
BenQ XL2411Z 144Hz monitor (set to 120Hz and with V-Sync in DIA)
Windows 8.1 64bit

Sajin
Sounds like DAI was patched to a newer version and is now causing the issue for you. Do you notice the stutter anywhere else?

No, so far only on DAI.

Tropickz
Try using 347.09 beta driver. if no results you can always go back to earlier version.

I had a horrible experience when updating to 344.75, I have an older Asus MB that doesn't support built in SLI and my driver went crazy and refused to allow me to enable SLI mode, even though my cards were bridged properly. Now that it works I'm a bit scared to update.

Sajin

kryptonian8077

Tropickz
Try using 347.09 beta driver. if no results you can always go back to earlier version.

I had a horrible experience when updating to 344.75, I have an older Asus MB that doesn't support built in SLI and my driver went crazy and refused to allow me to enable SLI mode, even though my cards were bridged properly. Now that it works I'm a bit scared to update.

You must be using DifferentSLI correct?

 
Pardon my ignorance, but by DifferentSLI do you mean SLIing two different cards? Then no, I have two identical GTX 970 cards.


Also I think I have figured this issue out. EVGA cards apparently like to run at 80c and the default fan speed curve seems to capped at 50%, this causes my GPU to reach 80c. But when my GPU reaches 80c it clocks itself down dynamically to remain at 80c.

I verified this by using Open Hardware Monitor, FurMark and 3DMark, and I noticed my GPU Core clocked itself down by as much as 178Mhz on my core, and 400Mhz on my shader just to remain at 80c.

I installed EVGA's PrecisionX 16 and created a custom fan speed curve that said (if temp >= 70 then speed up to 75%) It's just a bit louder now, but my GPU temp never gets above 76c now, so it doesn't clock down anymore.

I actually tested Fire Strike with the default quiet fan curve and my custom and I scored 1050 higher on my graphics score with my custom fan profile.
 
Edit:
If I play DAI with my custom fan curve, I never see the stuttering, but if I change the curve back to the quiet default, it starts stuttering again.

Reading the recent driver release notes shows that NVIDIA knows of this but oddly enough shows classified as a single gpu issue.
 
http://us.download.nvidia.com/Windows/347.09/347.09-win8-win7-winvista-desktop-release-notes.pdf