I've been having this issue on the Tonga, where the BIOS doesn't know the difference
between media decoding
and 3d rendering
as far as clock selection goes.
A typical anomaly I witness upon media decode, is upon starting the video the gpu utilization goes to 90-99%
at which time the GPU ups the clocks to full 3d speed on the core, memory, and voltage.
Then it goes back to 0-8%
or so, but every so often spikes to full 3d speed... Causing Up-And-Down power consumption. I think AMD needs to correct this and remove "Power Efficiency" option.
They should Re-Tune & Re-Work the Power Efficiency Option & Drivers from now on to have it enabled by default yet work correctly. I think it's an experimental option, they aren't sure if it should stick around.
I think what Power Efficency should mean is like Governor Control, like Android. Just teach
the video card bios/ driver to tell the difference
between 3d rendering load
and dxva load
The reason I say this is I tested out a BIOS where it wasn't allowed to leave STATE 0
for the core and memory while at 665 millivolts is as low as I've tested so far which droops to 662 millivolts.In State 0, AMD Graphics Horsepower can man handle 3840x2160 @ 23.97fps With EASE.
It stutters for a nano second at first and just runs smooth as butter... All the while using like 1 freakin watt!
Mind you it is at 99% continuous but using between 0.6 and 0.9 watts maybe a bit more at 99%... As well as continuous 37C.
This kind of ideology and thought process is similar to all ways of this world for which power can be saved. Like for instance in a car, the fuel map dictates less consumption of fuel at less revolution and high throttle amount. So it saves gas to let the rpm's droop and give it more gas to save fuel rather than downshifting spinning the engine revolutions higher with less throttle actually burns more fuel.
AMD has it so if utilization gets to a certain point, it auto-hops clocks to maintain reduced utilization at the cost of higher power consumption. So it's best to let STATE 0, go to 99 to 100% utilization all the time while on the desktop or watching dxva 4k. If State 0 isn't enough for Internet Video & Games assign the driver to the specific "Internet Video & Games" State which also gives smooth operation while at the least power consumption.
Another thing to consider is there is no need to go higher than 300Mhz
for Media Decoding... 3840x2160 is 8,294,400 pixels
, that's 8 Million 294 Thousand pixels per frame... We need 23.97 of them per second
. That's around 248 Million Pixels per second to decode 4k
. The R9 380X has 32 ROP's, so 300Mhz x 32 = 9 Billion 600 Million Pixels per second...
So it's clear AMD is wasting energy, energy flying out the window for absolutely nothing to gain but a high power bill.At idle & Decode, no more than 1 Billion Pixels per second is logical
... That means for 32 ROP's
we need just an awesome 32 MEGA HERTZ
on hand to sizzle through over 1 Billion Pixels per second while using Ultra-Micron-Nano Power Consumption... Take the lead in power efficiency with ease.
Default BIOS hops all over typical consumption 20 watts
for 1080p dxva, and 4k dxva can go up to 40 or more watts
and the heat goes way up too...
At 665 millivolts the fan stays off and it simply isn't using enough power to get above 40C or no more than 5 watts... Setting the TDP Limits all of them to 1 Watt, the card uses less than 1 Watt all the time especially during 4k decode. I literally saw less than 1 Watt!
Anyway, if you guys understand what I mean and might have suggestions I'd appreciate it. I already notified AMD of this though so will hope to see improvements in the 16.9.3 and beyond. Edited by chris89 - 9/27/16 at 5:27am