Dolphin on the pi 4?

[WODAK]

(01-28-2020, 03:10 AM)raspbyan Wrote: Check the video's comments. The Pi 4's CPU is overclocked to 2147 MHz, GPU at 750 MHz.

https://www.tomshardware.com/news/raspberry-pi-higher-overclock,40559.html
https://www.electronicsweekly.com/news/business/clocking-raspberry-pi-4-2019-10/

Withe the latest firmware u can't overcllock the GPU anymore...

link:


https://github.com/raspberrypi/firmware/issues/1290


Quoted from RP GitHub:

"Overclocking core and gpu frequencies has never been supported on pi4 (even before dvfs changes). It just happened that 600 was a magic number that had an integer divider from the channel frequency of the PLL. Even on older firmware, 610 would never have worked (however fast your Pi4 was).

The PLL/clock configuration is subject to change if we find settings that improve power consumption, performance or stability. And settings used may affect whether an overclock still works.
As @JamesH65 says, switching off dvfs is not feasible as the clocking strategy is now substantially different.
Currently v3d clock comes from PLLA=3GHz with a channel divisor of 6, and a clock divider of 2.
Requesting v3d_freq=600 will result in a fractional divider of 1.666 which means some clock pulses are effectively at 1GHz - no Pi4 will work like that. Rounding up the fractional divider should make this safe again, but you'd only have a v3d_freq of 500MHz.
The difficulty is that each PLL and channel divisor is shared by multiple clocks (e.g. v3d, isp, h264, hevc share PLLA, and many clocks share PLLC with core).
I'll try to have a look if we can do anything better. It should be possible to detect if an overclock requested has a non-integer divider that effectively exceeds the requested frequency and reduce the overclock so it doesn't. That will stop the crashing/failing to boot when things change.
I'll see if some limited gpu overclock could be supported. e.g. if v3d, isp, h264, hevc are all overclocked the same then increasing PLLA but leaving the dividers the same may be possible (no guarantees it will work on any specific Pi4, but it's something that can be tried).
Overclocking core is probably not possible - things like wifi, sdcard, composite, hdmi rely on PLLC and tend to fail when run with clocks that aren't as expected."