v18 Some observations playing HEVC on RPi using popcornmix/newclock5 18.0b2
#1
I build the latest git of popcornmix/newclock5 tried a few 10-bit HEVC clips on different RPi hardware: RPi2, RPi3, and RPi3B+.  What I found is that playback was unwatchable on the RPi2.  Decent but not perfect on the RPi3, and good to excellent on the RPi3B+.  I'm thinking there is some minimum clockrate needed to get smooth playback but am wondering what others are experiencing.  Is that trend about right?
Need help programming a Streamzap remote?
Reply
#2
(2018-09-27, 22:17)graysky Wrote: I build the latest git of popcornmix/newclock5 tried a few 10-bit HEVC clips on different RPi hardware: RPi2, RPi3, and RPi3B+.  What I found is that playback was unwatchable on the RPi2.  Decent but not perfect on the RPi3, and good to excellent on the RPi3B+.  I'm thinking there is some minimum clockrate needed to get smooth playback but am wondering what others are experiencing.  Is that trend about right?
 HEVC needs quite a bit of CPU and GPU power and SDRAM bandwidth, applying a bit of overclock can help - especially on the lower performance RPi2 and RPi3, but also on the 3B+.

I'm using these settings on my 3B+, without these German DVB-T (1080p50 HEVC) stutters
Code:
temp_soft_limit=70
gpu_freq=500
over_voltage=2
sdram_freq=580
over_voltage_sdram=5
sdram_schmoo=0x02000020

so long,

Hias
Reply
#3
(2018-09-27, 22:17)graysky Wrote: What I found is that playback was unwatchable on the RPi2.
 RPi2 has 2x less QPU units inside the GPU compared to RPi3/3B+. It will not be as fast as RPi3 even at identical clock rate.
Reply
#4
I'd add to the above:
I would (and do) use active cooling while watching HEVC content to avoid CPU throttling.
I have a 5v fan + a transistor to control it via gpio with simple script when the temperature reaches the threshold which I set to 60C.
Reply
#5
(2018-09-27, 22:53)smp1 Wrote: RPi2 has 2x less QPU units inside the GPU compared to RPi3/3B+. It will not be as fast as RPi3 even at identical clock rate. 

Not quite - GPU (including QPU) is identical on Pi1/Pi2/Pi3/Pi3+ (default clock frequency varies across products, but you can usually get the same behaviour with a a manual overclock).
The arm on Pi2 has half the Neon SIMD width compared to Pi3.
There are also architectural improvements and a higher clock frequency which gives about 50% more arm performance which helps somewhat
(not as much as you might imagine as with the QPU and VPU offload, the arm isn't always the bottleneck).
Reply

Logout Mark Read Team Forum Stats Members Help
Some observations playing HEVC on RPi using popcornmix/newclock5 18.0b20