Current state of Snapdragon-based CPUs in PPSSPP

[xsacha]

http://www.openssl.org/~appro/Snapdragon-S4.html <-- NEON is not good for Snapdragon :\

[vitality19]

(11-20-2013 01:50 PM)xsacha Wrote:  http://www.openssl.org/~appro/Snapdragon-S4.html <-- NEON is not good for Snapdragon :\

So that was with Snapdragon-S4 SoCs. Did nothing change at all with Snapdragon 200-800 series?

[Henrik]

"not good" is an exaggeration, NEON will probably still beat not using NEON in many many cases. It's not as fast as on other chips though.

[xsacha]

Explained here a bit better: https://plus.google.com/+nialldouglas/posts/YgbUb4mUXP2
Aside from the lower performance NEON, it has random latencies on the instructions.

[KingpinZero]

That would explain why exynos 4 based phones destroy the competition, their neon performance is unmatched. Sucks though that they are paired with scarce GPU power…
I wonder how does ppsspp performs with exynos 5?

[Henrik]

@xsacha, that one seems to imply that we should add THUMB-2 support to the JIT for optimal performance on Krait. That's so much work though that I'm really not sure I can be bothered...

[KingpinZero]

(11-21-2013 10:11 PM)Henrik Wrote:  @xsacha, that one seems to imply that we should add THUMB-2 support to the JIT for optimal performance on Krait. That's so much work though that I'm really not sure I can be bothered...

Depends only on what direction you and the team want PPSSPP to take. You thrown the emu on android platforms almost immediatly after the first public release, almost stating boldly that Android was one of the team target platform.

The success this wonderful piece of code on android proved you right

Fact is: Snapdragon CPUS are slowly begin to be "THE" hardware on androids (like Apple SGX ecosystem). S4,S600,S800 and S805 are basically being adopted from every brand, even chinese cheap ones such Lenovo, ZTE, Oppo and so on.

Which means that Snapdragon will be the baseline of Android devices in the future. Unfortunately afaik the NEON performance is something lacking even in S800, same will be with newer S805.
Same happens with S200 and S400.

This leads to me to think: is safe to not further optimize PPSSPP code because it will require a huge amount of work (like you said), by not implementing Thumb-2?

If that optimization isnt take into account, what will be the android version future, when snapdragons will be the largest machine base out there?

Questions questions....point is that Software Skinning proved that boosting performance is something that can be done without rewriting the whole code, which is awesome.

If is true that further optimizations can be done, i think we can stay with what we have right now. But as far as the optimization goes, decisions needs to be taken. In the future, which is approaching fast (as soon as Q1 2014 kicks in, we will see a flood of Snapdragon devices), what will be of ppsspp android?

[vitality19]

Then it seems that for now Snapdragon series will lag behind (if smth. doesn't change in their arm architecture), and it is useless (for now) to buy Snapdragons to play PPSSPP (and other emus as well) cause if not for emus, what these chips are good for? - to play some few decent games for Android? (imho) - although the market is flooded with these SoCs (rather powerful and cheap)

[Henrik]

Obviously ARM is a prime target. However I believe that THUMB-2 will only gain at most a few percent, that article seems to indicate so anyway.

I think I can get bigger gains through other optimizations that will benefit all ARM machines including Snapdragon, so while I will keep this one on the list, it's not top priority.

For example, NEON VFPU will benefit all ARMs that can do NEON. Just maybe a few percent less on Snapdragon than other platforms but I'm sure it will still help considerably in many games.

[vitality19]

Anyway, if I were a dev, I wouldn't bother with Snapdragons either, it's not our fault that their arm architecture is different (from a standardized one) and that it hurts performance.
I understand that it's really hard to optimize the emulator for every SoC, each requiring a special approach, and not to break things at the same time.

[25LEE]

I believe the only two games that I can play full speed without frameskip on my Z Ultra is Dragonball Z and Initial D..though I'm having a touch screen issue.. which ever button I hold becomes "unpressed" without even lifting my finger off the button

---

Also not sure if it's due to my tempered screen protector..

[Carter07]

(11-23-2013 04:35 AM)25LEE Wrote:  I believe the only two games that I can play full speed without frameskip on my Z Ultra is Dragonball Z and Initial D..though I'm having a touch screen issue.. which ever button I hold becomes "unpressed" without even lifting my finger off the button

---

Also not sure if it's due to my tempered screen protector..

Really?
I can play most games at 70-100% speed with a weak dual core A9 1ghz.

Please can you report the perf you are getting game per game with an s800?

[25LEE]

Lol that will take some time.. But a couple are very playable but need frame skip

[globe94]

@xsacha
its been a month ago, so sorry to bring this up again but..
u mention EGL config chooser here.


this morning i tried to read logs again & this is what i saw..
is this the EGL config u mentioned?

0.9.1-1661 page 1

page 2

page 3

this 1661 build has the auto rotate screen function & it works fine on mine. but its slow though.

0.9.1-1452 (the last fast build)

i tried many times but the result is always like this

and the latest 0.9.5-618 page 1

page 2


they have diffent results..
so i wonder..
does EGL Config makes big difference in speed?

& also can i ask to borrow a little of your precious time to make a build , with latest functions with also auto screen rotate function? ( i wanna try if still works pls )


and here are the complete logs..
if it can help.
0.9.1-1452

0.9.1-1661

0.9.5-618

[xsacha]

(11-25-2013 07:38 AM)globe94 Wrote:  they have diffent results..
so i wonder..
does EGL Config makes big difference in speed?

Yes, it can. Very interesting.

https://github.com/hrydgard/native/commi...c222b69a91
latest is using alpha 0/depth 24
16xx switched to alpha 8/depth 24
Slow build switched to alpha 8/depth 16
Before that it was using 'default'

I have an Adreno too but using Blackberry10 instead of Android and I have always used alpha 0/depth 24. I did try a few different settings but this is the one that seemed to work the best and recommended by Blackberry.