So one the first videos showing the capabilities of the Pro PS4.

Game is rendering at 1800p, checkerboard-rendered to 4k and looks crisp but not as crisp in motion and performance target seems to be 60fps but drops to low 30's are also seen. Game should be locked to 30fps.

"A first *early* look at Killing Floor 2 running on PlayStation 4 Pro. The visual quality is a nice step up from what we've seen on the standard PlayStation 4 but what about frame-rate? Is this the kind of upgrade we can expect on average from the PS4 Pro?"

View on YouTube

source: https://www.youtube.com/watch?v=fSvYJD-vGhI

Transcript for people at work without yt-access:
0:00
tripwires killing floor has become quite
0:11
popular and with killing for to ps4
0:13
owners are finally getting in on the
0:15
action while the game has been available
0:18
in early access for quite some time now
0:20
on the pc side the upcoming playstation
0:22
4 version will be released this November
0:25
it's also one of the first games shown
0:28
and announced with full support for the
0:30
playstation 4 pro which is what you're
0:33
seeing in this video footage here to
0:35
start with killing floor 2 runs on a
0:37
modified unreal engine 3 and is aiming
0:40
for 60 frames per second on both ps4 pro
0:42
and the standard ps4
0:46
tripwire has also confirmed the game is
0:49
rendering it 3200 by 1800 while using
0:53
checkerboard rendering to deliver the
0:55
final 4k image I've seen this
0:57
checkerboard rendering technique in
0:59
person now at egx this year and I was
1:02
generally impressed with the quality it
1:04
really does deliver an effective 4k
1:07
experience you can really see the
1:09
individual pixels line up with the pixel
1:11
grid on a 4k screen and I think that's
1:13
very important here only when sitting
1:16
mere inches from the screen to the
1:18
limitations become evident and only then
1:20
only in motion but even still it does
1:23
look good
1:24
the pro version also makes use of the
1:26
games ultra textures thanks to the extra
1:29
memory available in the system and
1:31
initial impressions also suggest that
1:32
we're looking at a presentation
1:33
comparable with the higher settings
1:35
available on the pc and while it's not a
1:38
particularly stunning-looking game it
1:40
does at least look very crisp and clean
1:42
on the ps4 pro and it's a big step up
1:45
from the standard ps4 running the 1080p
1:52
now when we transition over to the
1:54
performance analysis we do begin to see
1:57
some problems the promised 60
1:59
frames-per-second update isn't really
2:01
happening here and instead we have a
2:03
completely unlocked frame rate that
2:05
averages more around 50 frames per
2:07
second instead and some of the busier
2:10
seems that actually dropped all the way
2:11
down below 40 frames per second while at
2:15
the other end of the spectrum we do see
2:16
occasional pockets of full 60 but it's
2:19
really never very consistent now for
2:22
comparison i've actually played killing
2:24
42 on a standard ps4 as well since it
2:27
was available this year both at e3 and
2:29
then later at VGX and it was actually
2:32
running rather similarly the frame rate
2:35
is still unlocked and generally under 60
2:38
frames-per-second leading to a wildly
2:40
inconsistent experience the stock ps4
2:44
version of course is rendered at a lower
2:45
resolution just as you'd expect
2:47
so you're still getting that big boost
2:49
in visual quality but no real
2:51
improvement to frame rate on the pro so
2:54
with just one month until the game ships
2:56
what can we honestly expect them while
2:59
the game is still in its pre-release
3:01
state we're so close to release at this
3:03
point that it seems likely that this
3:04
might be what we're getting to be honest
3:07
it's a tad disappointing overall and it
3:11
leaves the game and a slightly
3:12
troublesome state without knowing where
3:14
the game is actually bottlenecking it's
3:16
tough to say how things could be
3:17
improved could reducing visual quality
3:20
and key areas or dropping the resolution
3:23
or perhaps implementing a dynamic
3:24
resolution offer enough Headroom to hit
3:27
a proper 60 frames-per-second here and
3:29
if not it would at least be nice to
3:32
offer users the option to cap the frame
3:34
rate at 30 frames per second for those
3:36
of us that value a more consistent
3:38
experience while still allowing players
3:40
to play with them unlocked frame rate if
3:42
they preferred who knows maybe even
3:44
using the 30fps cap would allow them to
3:46
hit native 4k it's not really clear
3:49
either way a wildly unstable framerate
3:52
like this doesn't really leave a great
3:54
first impression but again this is still
3:55
unfinished so things could change by
3:57
launch will certainly
3:59
soon enough when the final game hits and
4:01
we're eager to see how it holds up in
4:03
the end maybe they'll even be able to
4:05
sneak in a high dynamic range mode but
4:08
that's all the video footage we really
4:09
have for now but if you enjoyed this
4:11
video be sure to like subscribe and
4:13
follow us on twitter and until next time
4:15
this is Jon signing off
4:18
and if you like shooters he might also
4:21
enjoy this video as well

You can't just choose an arbitrary resolution.

Killing Floor is a game with a massive amount of enemies. The game is most likely CPU limited when it drops

Yes, the CPU in PS4P is still very low, just clocked a bit higher. This is a huge bottleneck for games and I am eager to see how other games will perform in comparison to the standard PS4.

This is quite likely. They are barely more than an indie dev (started out doing mods out of their homes for Unreal Tournament), and are probably not the best indication of anything on PS4P (or competent/budgeted enough to deal with great optimization for the garbage AMD Jaguar compared to Intel PC CPUs).

It reminds me of when everyone was freaking out over how god-awful that Sniper game was on X1 back in the day. It had atrocious tearing and optimization, but at the end of the day with evidence like FH2/FH3/Gears 4 and even Ryse, the X1 was capable when matched with capable devs.

Tripwire Interactive is ... well, I will be nice and say they try hard with limited resources.

As with anything with these limited consoles (even PS4P or supposed Scorpio specs), it will be a mixed bag. They are hugely compromised even for today.

2715x1527 isn't exactly twice the pixels of 1080P and half of 4k.

It would be a waste of time to even render at that resolution.

If you so desire I can go into elaborate technical detail with basic math?
I would prefer not to untill there are more replies in this thread though so I can prove everyone who is incorrect, wrong, at the same time.

Because scalers have algorithms optimized for specific set resolutions, the Playstation 4 is upscaling it's games after the initial rendering is completed, checkerboard or not.

You would also be better using two 1080P frames (Checkerboard) or 2560x1440 and then throwing more Anti-Aliasing at the problem.
A higher-resolution isn't always better if it means you need to make compromises somewhere else.

suggesting all PS4 games that supporting Pro version should have at least 3 gameplay option

01- best resolution mode
02- best effect mode
03- best frame-rate mode

We will have to see how much effort 3rd party devs will put in the pro mode.