My experiment machines are Note 3 and Note 4.
I have a free edition of DS-5 Version-20
I have couple of questions with regards to GPU BandWidth stats reported by Streamline -
- On T628 (Note3) Read and Write BEATs reported on a simple app seem to be 66% of expected value. Is this a known bug on bandwidth PMs on T6xx?
My test app reads in randomly generated texture and draws it on the screen - since every frame is a new/random texture there is no Transaction elimination in play.
- I tried the same experiment on Note 4 - but Rd/Wr BEATs and many other stats stay blank (report Zero) on this T7xx system. Is this a known issue? are these stats not available on T7xx Mali arch OR is this something to do with using free version of DS-5?
Thanks !
> On T628 (Note3) Read and Write BEATs reported on a simple app seem to be 66% of expected value.
There is a known issue in that version of DS-5 in handling counters for GPUs with more than 4 cores; you are seeing the bandwidth for 4 of the 6 cores, hence the 66% of expected score.
> I tried the same experiment on Note 4 - but Rd/Wr BEATs and many other stats stay blank (report Zero) on this T7xx system.
Mali-T760 performance counters are not supported in the version of the driver shipping in the Note 4, sorry.
Thanks Peter.
Regarding 'Mali-T760 performance counters are not supported in the version of the driver shipping in the Note 4, sorry.'
Pls note that for Note-4 I did follow the procedure of re-building an open-source kernel with counter support + rebuilding gatord/gator.ko for T7xx arch as explained in Using DS-5 Streamline with Mali on Samsung Galaxy Note 3 & 10.1
Could you clarify if you meant that T7xx PMs are not supported on this custom built kernel? Is there any plan to release an open-source driver with PM support in future?
> Could you clarify if you meant that T7xx PMs are not supported on this custom built kernel?
Correct - the gator/mali driver integration in the current Note 4 kernel does not support Mali-T760 counters.
Both of the issues you have hit - support for more than 4 cores and support for the Mali-T700 family - are supported in our final r5p0 driver release.
> Is there any plan to release an open-source driver with PM support in future?
The stock r5p0 kernel drivers for the Mali-T700 series GPUs is available at the link below, but are not much use without the matching user-space drivers:
Mali Drivers
The full kernel tree linked in the guide is provided via Samsung, not directly from ARM, so this is a question best aimed in their direction (we do provide driver binaries for a couple of developer-friendly platforms, but the Note 4 is not one of these). Note you will need both the r5p0 kernel and the r5p0 user-space drivers.
HTH,
Pete
Thanks for the reply Peter - that answers my question.
A side query - are there any developer friendly platforms for purchase that have T7xx GPU in it?
The only Mali-T760 developer board I am aware of at the moment is this one, but I'm not used it personally so not sure availability, software support, etc (It's not one of the boards we are providing binary drivers for).
There will no doubt be more boards available as chipsets containing the Mali-T760 become more widely available.
HTH, Pete