Eurogamer put up an article today with a hands on look with an actual PS4 and some of its games
"No smoke or mirrors from Sony - everything we saw was running on PS4 hardware. But it's still early days and many of the games clearly require a lot of optimisation."
Here are some quotes about the games they tried below
When it comes to the tricky issue of control and response, Killzone: Shadow Fall currently delivers a largely 25-30FPS experience with v-sync engaged, where a long overview of the forest tests the hardware most. A strong trace of input lag is felt when turning the analogue sticks - a quirk that hangs over from the Killzone 2 days. It's a delay in response that is impossible to ignore after playing snappier low-latency shooters, and at the default 50 per cent sensitivity for the X and Y axis proved tricky to adapt to. Migrating to the new and more shooter-friendly Dual Shock 4 controller isn't the cause here, as this is the only game we test with such problems. Rather, the issue is likely to be the result of latency being built up over the course of a long and complex rendering pipeline.
When questioned, Evolution Studios confirms that it's pushed for a full-fat 1080p presentation, falling in line with all Sony's other leading PS4 titles. Unfortunately, this higher resolution only amplifies the low quality, blurry, flat-looking textures used across this level, which would easily look at home on current-gen hardware. It's also a shame that, while the scenery draw distance is broad, there's an incredible amount of pop-in for trees and waving NPCs as we approach at high speeds...With regards to performance, we're surprised to find DriveClub is running at 30fps with permanent v-sync - an unusual step for any modern-day racer putting heavy emphasis on shaving seconds from lap times. It is noted that 60fps is something the team strives for, but no promises can be made; in the interest of providing a smooth E3 experience it remains decidedly locked at 30fps for now. Alas, even this number isn't held convincingly during our play-testing, and the game dips noticeably below this point - a feeling of 20fps being achieved during doughnut-turns, where lots of tyre friction smoke is produced. Bearing in mind the PS4's next-gen tech (not to mention its 32 ROPs), we're somewhat surprised to see alpha transparency effects still having such an obvious impact on performance.
That's the next-gen hook, but little else is in place to enthrall. The Pixar aesthetic is let down by some muddy image quality, and heavily dithered shadows. We're promised 1080p native resolution here, but Knack doesn't look as crystal clear as we'd expect from such a pixel count - perhaps in part owing to the HDTV settings being used at the exhibition. It's a real disappointment on the grounds of image quality, and while the transparency effect on Knack and the big, beautiful ocean view during the first stage are visual treats, there isn't a whole lot to the rest of stages shown. Certainly, the physics are impressive and technically taxing. All the bits and pieces that whip around Knack indeed feel like individual objects, taking advantage of the game's per-object motion blur. The only problem here is that, despite being a 30fps game in target, we see dramatic frame-rate drops when too many of these pieces go zooming across the screen to form a shell around Knack. To achieve this bullet-point trick, the performance has to take a noticeable hit in the current build. Excluding this effect, the frame-rate isn't smooth for the current built in general, and it stutters even as Knack trots through empty streets unengaged. There's no evidence of tearing, but this choppy motion is surprising given its overtly simplistic visual style. Fortunately it evens out during the later interior stages based around the mansion and cave, but some optimisation is still clearly needed on the game before the PS4's launch.
When it comes to performance, the game is v-synced, but very jittery in the frame-rate stakes for transitions into new areas, and throughout an entire sequence where a bridge burns to cinders. It also appears to run at native 1080p, though there's little being achieved here visually which we haven't already seen before, likely showing its prior development history on weaker platforms. That is, with the exception of its impeccable lighting - a striking feature as lamp-light streams through the city's fogged archways, and one which feeds into a gameplay design predicated on hiding in shadows. A curious trend among other next-gen game we've seen - such as Killer Instinct - is the decision to ramp up the particle count to dazzling degrees for explosions. That's true here, where lighting on particles is truly striking as flaming debris crumbles down from a bridge during one later segment. It's only a shame that surrounding texture-work and alpha effects appear so mismatched with these more "next-gen" elements in this current build, and we hope to see everything ramped up to an even level for the final release.
We leave Sony's E3 booth undoubtedly impressed, with two key takeaways in light of the Xbox One's rivalling offerings. Firstly, though almost all launch titles on show appear to be running directly from PS4 hardware, it's a touch disappointing to discover the likes of Thief and Assassin's Creed IV: Black Flag are only currently being demonstrated by proxy of an on-hand developer. This was a very closely guarded event indeed, suggesting a lack of confidence in the progress of development for some of these titles. Even so, Knack, DriveClub and Warframe do give us absolute, no-holds barred freedom to toy with the most current builds as long as we please...When it comes to the state of software development on PS4, the situation as it stands is surprising. On the one hand, freely playable first-party titles such as Knack and DriveClub suffer from noticeable frame-rate stutters down from 30fps, while on the other, "hands off" demos for the new Infamous and Assassin's Creed games appear to run without a perceptible hitch. This is in stark contrast to the playable software confirmed to be running direct from Xbox One hardware, such as Forza Motorsport 5 and Killer Instinct, which benefit to no end for targeting the 1080p60 gold standard, and largely succeed in doing so.
Such a disparity in performance is far from the outcome we had expected going in to E3, but Sony's agenda with this initial wave of games is clearly hinging on visual fireworks rather than maximising frame-rates to the full 60Hz refresh.
So it seems some games run slightly poorer than expected with KZ:SF feeling like sub 30 fps at times but further optimisation before launch might iron that out. Sad part is it has the input lag of KZ 2 which means I'm avoiding it completely.
Driveclub is also sounding poor with dips feeling as low as 20 fps in a racer is just a joke TBH
TL;DR Sony are going for more flashy graphics at the expense of performance from these hands on