i did some research regarding the topic and want to share my finds/work with everyone.
the comparison shows all pvs of MSM8974AB 2.3ghz (one m8 - pro_rev1_2p3g) and MSM8974AC (gs5 - pro_rev1_2p5g).
all table data manually taken from latest one m8 kernel sources.
in addition i added one m7 (APQ8064) and lumia 930 (2p2g) chips (pvs0 and pvs6) for intresting comparison.
with this guide in combination with root access, custom kernel and trickster mod you can find out your cpu's pvs bin (compare default voltages).
alternative to find your pvs: adb shell from recovery (su) "cat /proc/last_kmsg | grep bin: -i".
also it serves as a template to try out higher pvs settings on your cpu.
as you see, qualcomm did some impressive work with binning and trying to get most out of each cpu.
however there is usually still some headroom for optimizations if you do some efforts.
same research i already did for the m7 (APQ8064 compared to APQ8064T of galaxy s4) if someone is intrested (let me know).
i take no responsibilities for potential harm you do to your device. all on your own risk.
please share your results of which pvs level works on your personal chip (also tell stock pvs value of course).
best max frequency (sweet performance/power spot):
MSM8974AB 2.3ghz - 1.34ghz
MSM8974AC 2.5ghz - 1.57ghz
MSM8974v2 2.2ghz - 1.34ghz
APQ8064 1.7ghz - 1.24ghz
APQ8064T 1.9ghz - 1.35ghz
best screen-off frequency (this varies if you try higher pvs settings):
Snapdragon 801 2.3ghz MSM8974AB - One M8
MSM8974AB 2.3ghz PVS 0 - 300mhz
MSM8974AB 2.3ghz PVS 1 - 346mhz
MSM8974AB 2.3ghz PVS 2 - 422mhz
MSM8974AB 2.3ghz PVS 3 - 499mhz
MSM8974AB 2.3ghz PVS 4 - 576mhz
MSM8974AB 2.3ghz PVS 5 - 652mhz
MSM8974AB 2.3ghz PVS 6 - 499mhz
MSM8974AB 2.3ghz PVS 7 - 576mhz
MSM8974AB 2.3ghz PVS 8 - 652mhz
MSM8974AB 2.3ghz PVS 9 - 729mhz
MSM8974AB 2.3ghz PVS 10 - 806mhz
MSM8974AB 2.3ghz PVS 11 - 883mhz
MSM8974AB 2.3ghz PVS 12 - 960mhz
MSM8974AB 2.3ghz PVS 13 - 1036mhz
MSM8974AB 2.3ghz PVS 14 - 960mhz
MSM8974AB 2.3ghz PVS 15 - 1036mhz
Snapdragon 801 2.5ghz MSM8974AC - Galaxy S5
MSM8974AC 2.5ghz PVS 0 - 422mhz
MSM8974AC 2.5ghz PVS 1 - 499mhz
MSM8974AC 2.5ghz PVS 2 - 576mhz
MSM8974AC 2.5ghz PVS 3 - 652mhz
MSM8974AC 2.5ghz PVS 4 - 729mhz
MSM8974AC 2.5ghz PVS 5 - 806mhz
MSM8974AC 2.5ghz PVS 6 - 652mhz
MSM8974AC 2.5ghz PVS 7 - 729mhz
MSM8974AC 2.5ghz PVS 8 - 806mhz
MSM8974AC 2.5ghz PVS 9 - 883mhz
MSM8974AC 2.5ghz PVS 10 - 960mhz
MSM8974AC 2.5ghz PVS 11 - 1036mhz
MSM8974AC 2.5ghz PVS 12 - 1113mhz
MSM8974AC 2.5ghz PVS 13 - 1190mhz
MSM8974AC 2.5ghz PVS 14 - 1113mhz
MSM8974AC 2.5ghz PVS 15 - 1190mhz
Snapdragon 800v2 2.2ghz MSM8974v2
MSM8974v2 2.2ghz PVS 0 - 345mhz
MSM8974v2 2.2ghz PVS 1 - 499mhz
MSM8974v2 2.2ghz PVS 2 - 422mhz
MSM8974v2 2.2ghz PVS 3 - 499mhz
MSM8974v2 2.2ghz PVS 4 - 576mhz
MSM8974v2 2.2ghz PVS 5 - 499mhz
MSM8974v2 2.2ghz PVS 6 - 576mhz
Snapdragon 600 1.7ghz APQ8064 - One M7
APQ8064 1.7ghz PVS 0 - 594mhz
APQ8064 1.7ghz PVS 1 - 594mhz
APQ8064 1.7ghz PVS 2 - 702mhz
APQ8064 1.7ghz PVS 3 - 810mhz
APQ8064 1.7ghz PVS 4 - 702mhz
APQ8064 1.7ghz PVS 5 - 810mhz
APQ8064 1.7ghz PVS 6 - 702mhz
Snapdragon 600 1.9ghz APQ8064T - Galaxy S4
APQ8064T 1.9ghz PVS 0 - 702mhz
APQ8064T 1.9ghz PVS 1 - 702mhz
APQ8064T 1.9ghz PVS 2 - 702mhz
APQ8064T 1.9ghz PVS 3 - 810mhz
APQ8064T 1.9ghz PVS 4 - 702mhz
APQ8064T 1.9ghz PVS 5 - 702mhz
APQ8064T 1.9ghz PVS 6 - 702mhz
best min frequency:
lowest possible setting (300mhz in case of MSM8974)
i highly recommend to run those values (exept if you are actually playing demanding 3d games).
use trickster mod frequency lock feature to do so. you will experience amazing battery life.
how to get the maximum battery life:
if you have a MSM8974AB pvs 6 for example, try the following steps:
try the next higher pvs levels (pvs7). don't try AC pvs values on AB chips.
AB chips are binned for lower frequencies while AC are binned for higher frequencies (duh).
so if you have a AB chip, work your way up the AB pvs values until you have freezes or similar and move back.
if you have a AC chip, work your way up the AC pvs values etc...
if you found highest setting that does not cause any problems after intensive testing and usage:
congratulations, you did it.
how to get the maximum frequency:
first try higher than stock maximum clock and see how it behaves.
if you don't reach your desired clockspeed, try the next lower pvs setting of your chip. yes, i said LOWER.
this gives the processor more voltage to reach higher overclocks.
i don't recommend it tho since we all want our phones to last as long as possible usually.
signs of too high overclock:
device lockups (not responding) or sudden reboots during heavy load.
signs of too low voltage:
problems with audio when screen off, long screen wakeup time, lockups and reboots even without cpu-load.
caused by not enough voltage for low frequency levels usually.
snapdragon 805 infos:
here you go. i digged in the kernel sources and found it.
2.7GHz RC1 - speed2-bin-v1 (PVS levels 0-15)
2.7GHz RC0 - speed2-bin-v0 (PVS levels 0-15)
2.5GHz RC1 - speed1-bin-v1 (PVS levels 0-15)
2.5GHz RC0 - speed1-bin-v0 (PVS levels 0-15)
2.3GHz RC1 - speed0-bin-v1 (PVS levels 0-15)
2.3GHz RC0 - speed0-bin-v0 (PVS levels 0-15)
there seem to be two different variants of the 805 (RC0 and RC1).
RC0 seems to use less voltage at higher frequencies.
RC1 seems to use less voltage at lower frequencies.
the voltage tables you can take from the attached txt.
i also attached a txt containing how the bus clocks behave in relation to the cpu-frequency.
snapdragon 805 pvs 2.7ghz RC0.txt
snapdragon 805 pvs 2.7ghz RC1.txt
snapdragon 805 pvs 2.5ghz RC0.txt
snapdragon 805 pvs 2.5ghz RC1.txt
snapdragon 805 pvs 2.3ghz RC0.txt
snapdragon 805 pvs 2.3ghz RC1.txt
snapdragon 805 bus ratios.txt
fixed some flaws (22 downloads of v1)