DX9 vs DX11

[KokonoeAiyoko]

So I was curious about performance among the two and used the Heavensward Benchmark to test both. The scores ended up being in favor of DX9.

-Specs-
CPU: i7 4770k OC to 4.3 GHZ
GPU: GTX 980 Ti Classified (Stock)
RAM: 16GB DDR
Resolution: 1920x1080

DX9

Score: 19207
Average Frame Rate: 159.239
Performance: Extremely High
 -Easily capable of running the game on the highest settings.
Loading Times by Scene
  Scene #1	2.026 sec
  Scene #2	4.888 sec
  Scene #3	3.246 sec
  Scene #4	2.977 sec
  Scene #5	2.898 sec
  Scene #6	1.766 sec
Total Loading Time	17.804 sec

DX11

Score: 18018
Average Frame Rate: 137.386
Performance: Extremely High
 -Easily capable of running the game on the highest settings.
Loading Times by Scene
  Scene #1	1.205 sec
  Scene #2	4.987 sec
  Scene #3	3.650 sec
  Scene #4	3.575 sec
  Scene #5	3.417 sec
  Scene #6	1.345 sec
Total Loading Time	18.180 sec

So DX9 is the clear winner here, although I noticed in the final scene where there are tons of PC's and NPC's, DX11 wins for load times. (Which is understandable as DX11 has better CPU usage so is better for being in towns crowded with players than DX9 is).

But wait! I realized something. DX11 has new graphical features, which in turn make it more taxing when enabled. So I ran the benchmark one last time with the graphical settings matched to the DX9 client and these are the results.

Score: 21233
Average Frame Rate: 170.012
Performance: Extremely High
 -Easily capable of running the game on the highest settings.
Loading Times by Scene
  Scene #1	1.172 sec
  Scene #2	4.883 sec
  Scene #3	3.645 sec
  Scene #4	3.377 sec
  Scene #5	3.256 sec
  Scene #6	1.386 sec
Total Loading Time	17.721 sec

A dramatic increase! Essentially I put Ambient Occlusion to "High" since that is the max on the DX9 client. Set Tessellation to Standard and Real Time Reflections to "High" as that is the max in the DX9 client as well. I didn't see Parallax Occlusion in the benchmark though surprisingly, so we'll just ignore that DX11 feature for now.

TL;DR
DX11 seems to be superior in performance overall. DX9 has it beat on certain instances, but being as this is an MMO and other players will be around including enemies and NPCs, you should theoretically have better performance overall with DX11.

[KarstenS]

But wait! I realized something. DX11 has new graphical features, which in turn make it more taxing when enabled. So I ran the benchmark one last time with the graphical settings matched to the DX9 client and these are the results.

There is also a profile to match the DX9 maximum settings while using DX11 benchmark.

The big advantage of the DX11 client is a better multi GPU handling. DX11 performs alot better than DX9 with more than one GPU.

Similar increase with DX12, where multi GPU and multi CPU got optimized alot compared to DX11.

[Hyperia]

I expect DX9 to be phased out in 5.0 and as much as I would love to see DX12, I don't expect to see another major overhaul in this game.

[KokonoeAiyoko]

I expect DX9 to be phased out in 5.0 and as much as I would love to see DX12, I don't expect to see another major overhaul in this game.

I hope we do get DX12 so we could potentially get anti aliasing options.

[basketofseals]

I expect DX9 to be phased out in 5.0 and as much as I would love to see DX12, I don't expect to see another major overhaul in this game.

I sure hope not. DX11 crashes extremely often with FFXIV. It would pretty much make me unable to do any group content.

[Selova]

I sure hope not. DX11 crashes extremely often with FFXIV. It would pretty much make me unable to do any group content.

Sounds like a problem on your end. I've never had the game crash because of DX11.

[Senliten]

Sounds like a problem on your end. I've never had the game crash because of DX11.

Tech Support Issues says 'hi to all of us having the issue since post HW'

[Nitblade]

I'm on Nvidia Gtx 1060 on DX11 and never had a crash related to video.
Are you using AMD? or maybe driver version issue?

[Nightroad]

Running two Nvidia Gtx 1080 ti in sli on a I7-7700k @5.0GHz without any crashes.
Win 10 64bit Home
Driver version 382.33

[basketofseals]

I'm on Nvidia Gtx 1060 on DX11 and never had a crash related to video.
Are you using AMD? or maybe driver version issue?

Nvidia GTX 750, and uninstalling and reinstalling drivers hasn't helped. DX11 also runs noticeably worse for some reason that I cannot fathom. I can lose anywhere between 5 and 12 frames per second.