I recently started playing Skyrim again after about a year hiatus. Since I last played I built a new machine:

GPU- EVGA Nvidia 770 4GB

RAM- Corsair Vengence 16 GB

MOBO- ASUS Z87-C LGA 1150 ATX

Processor- i7-4770 Haswell 3.4ghz

HD- Samsung 250GB SSD

I played for a few weeks with no problems with only about a dozen mods installed.

About a week ago I tried an ENB (Real Vision) and didn't like the frame rate drop so I followed the uninstall instructions and no problems until I decided to start a new PC that did not use any fast travel. I then started having CTD while riding a horse and only while riding a horse. It would happen about 1-2 minutes into riding the horse. Before trying the ENB I had been running several graphics and texture mods with no problems. I have never installed any kind of horse mod before. In total I had 63 mods running before trying the ENB.

I tried to trouble shoot by stressing the game and my hardware. I deleted the skyrim.ini files and pref.ini files and let the game create new ones. I enter the game and used console player.setav speedmult 1500 and tcl. I flew around the map and CTD in about 60 sec. I then deactivated every graphics and texture mod and repeated still CTD.

I use the LOOT and TES5Edit utilities as well.

Any trouble shooting help would be appreciated.

I decided to start a new PC that did not use any fast travel.

What you mean with that ???

They mean that they aren't using Fast Travel (e.g. using Map to Auto-Travel to cities, or using the Caravan). So they will be use a horse a lot, or walking. PC = Player (Playable) Character.

@OP. I doubt its directly related to horses, as its not crashing immediately. Maybe one or multiple mods are causing too much to be loaded into memory. Quick-traveling may prevent some stuff from loading. It may be scripting/loot related versus a purely graphical/texture issue.

To troubleshoot the issue, you'll probably have to disable all mods and start a new game, then slowly add mods until you start crashing. You could post your Mod List, maybe someone knows of a mod conflict or other known issues.

I figured it out finally, I had too many outside environment textures/graphics mods competing with each other and it was eating up my vram.