User avatar
bleep42
Posts: 156
Joined: Wed Mar 07, 2012 12:43 pm
Location: Sussex

Re: Pi 4 - full specification of VideoCore 6

Tue Sep 10, 2019 12:10 pm

Akane wrote:
Tue Sep 10, 2019 6:23 am
No, nope. The correct theoretical performance of the GPUs is as follows:

VideoCore IV @ 250MHz: 250 [MHz] x 3 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 24 Gflop/s
VideoCore IV @ 300MHz: 300 [MHz] x 3 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 28.8 Gflop/s
VideoCore VI @ 500MHz: 500 [MHz] x 2 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 32 Gflop/s

That then begs the question, is the 3rd slice still present on the silicon, but not currently enabled in the hardware metal layer, thus allowing for an easy future Pi4+ with 48Gflop/s? ;-)
I know, "no comment"... :-)

User avatar
Akane
Posts: 50
Joined: Tue May 27, 2014 1:20 pm
Location: Tsukuba, Japan

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 5:03 am

bleep42 wrote:
Tue Sep 10, 2019 12:10 pm
Akane wrote:
Tue Sep 10, 2019 6:23 am
No, nope. The correct theoretical performance of the GPUs is as follows:

VideoCore IV @ 250MHz: 250 [MHz] x 3 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 24 Gflop/s
VideoCore IV @ 300MHz: 300 [MHz] x 3 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 28.8 Gflop/s
VideoCore VI @ 500MHz: 500 [MHz] x 2 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 32 Gflop/s

That then begs the question, is the 3rd slice still present on the silicon, but not currently enabled in the hardware metal layer, thus allowing for an easy future Pi4+ with 48Gflop/s? ;-)
I know, "no comment"... :-)
As for VC4, there are four slices in the reference manual https://docs.broadcom.com/docs/12358545 p.13, so IMO there actually are four slices on VC4, and one of them is disabled due to yields.
As for VC6, there are two slices per a V3D core https://gist.github.com/phire/6542d2769 ... a0470f45cd , but I have "no comment" how many slices are actually there. However, VC6 can have multiple V3D cores (each core consists of two or so slices). There are relevant register definitions ("Per-V3D-core registers") in https://git.kernel.org/pub/scm/linux/ke ... v3d_regs.h , and the open-source DRM driver states that it only supports single core https://git.kernel.org/pub/scm/linux/ke ... drv.c#n272 . So IMO there may be multiple cores in VC6, and only one of them is enabled due to yields or difficulties in the graphics software stack.

Technocolour
Posts: 55
Joined: Thu Jul 04, 2019 6:23 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 5:43 am

Akane wrote:
Fri Sep 27, 2019 5:03 am
As for VC4, there are four slices in the reference manual https://docs.broadcom.com/docs/12358545 p.13, so IMO there actually are four slices on VC4, and one of them is disabled due to yields.
As for VC6, there are two slices per a V3D core https://gist.github.com/phire/6542d2769 ... a0470f45cd , but I have "no comment" how many slices are actually there. However, VC6 can have multiple V3D cores (each core consists of two or so slices). There are relevant register definitions ("Per-V3D-core registers") in https://git.kernel.org/pub/scm/linux/ke ... v3d_regs.h , and the open-source DRM driver states that it only supports single core https://git.kernel.org/pub/scm/linux/ke ... drv.c#n272 . So IMO there may be multiple cores in VC6, and only one of them is enabled due to yields or difficulties in the graphics software stack.
The architecture supporting four slices seems like a reasonable thing, even if this implementation was chosen to be 2 and no redundancy or 4 minus 2, or any of the other permutations. For context a Turing core is iirc "512 bit" (it does 16 FP32 MUL operations + 16 FP32 ADD in one clock). One VC6 slice is doing 4 MUL or 4 ADD, and 4 of them would be doing 4x4 = 16, or 32 FP16.

https://www.nvidia.com/content/dam/en-z ... epaper.pdf

IIRC, the GPU is vastly smaller than the CPU complex and given that the process is old and stable, I speculate that it is likely that the RPi4 GPU only has two slices on the die, and that it doesn't have any yield improvements in terms of shut off slices.

ejolson
Posts: 3823
Joined: Tue Mar 18, 2014 11:47 am

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 6:17 am

bleep42 wrote:
Tue Sep 10, 2019 12:10 pm
Akane wrote:
Tue Sep 10, 2019 6:23 am
No, nope. The correct theoretical performance of the GPUs is as follows:

VideoCore IV @ 250MHz: 250 [MHz] x 3 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 24 Gflop/s
VideoCore IV @ 300MHz: 300 [MHz] x 3 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 28.8 Gflop/s
VideoCore VI @ 500MHz: 500 [MHz] x 2 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 32 Gflop/s

That then begs the question, is the 3rd slice still present on the silicon, but not currently enabled in the hardware metal layer, thus allowing for an easy future Pi4+ with 48Gflop/s? ;-)
I know, "no comment"... :-)
To put VideoCore floating-point timings in perspective, here are the numbers for a few PC graphics cards:

Code: Select all

Model               Year   Launch Price   Single Precision
GeForce 8800GTS640  2006       $449          228 GFLOPS
GeForce 8600GT      2007       $159           76 GFLOPS
GeForce 1060Ti      2016       $139         2138 GFLOPS
Titan V             2017      $2999        14900 GFLOPS
GeForce GTX1650     2019       $149         2984 GFLOPS
Radeon VII          2019       $699        13440 GFLOPS
It's very difficult to figure price/performance, because the theoretical numbers can be very different than what one is actually able to achieve on any specific calculation.

In practice, besides speed it's quite important to have easy to use software tools for offloading computations onto the GPU. Therefore, even though the GPU on the Raspberry Pi is not super fast, it would still be useful from an educational point of view to have something like CUDA to program it.

User avatar
Gavinmc42
Posts: 4049
Joined: Wed Aug 28, 2013 3:31 am

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 7:43 am

Therefore, even though the GPU on the Raspberry Pi is not super fast, it would still be useful from an educational point of view to have something like CUDA to program it.
CUDA is Nvidia specific?
We have OpenCL on Pi4's now.
It's in the mesa source and mesa demos.
There is OpenCL on earlier Pi's based on doe300's work, not sure if it is full implementation yet.

Arm's Compute Library should be able to use OpenCL now?

With OpenGLES3.1 now releasing that brings in Compute Shaders.
No idea how to use them yet.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24162
Joined: Sat Jul 30, 2011 7:41 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 8:53 am

Gavinmc42 wrote:
Fri Sep 27, 2019 7:43 am
We have OpenCL on Pi4's now.
We do? News to me.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I think it’s wrong that only one company makes the game Monopoly.” – Steven Wright

User avatar
Gavinmc42
Posts: 4049
Joined: Wed Aug 28, 2013 3:31 am

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 12:01 pm

Maybe we don't :(
The mesa demo slang apps are reporting errors.
Install CLinfo and check.
Rats, it's masked in Gentoo64, er what does that mean?

https://www.mesa3d.org/intro.html
Mesa includes OpenCL.
Just assumed because we had Mesa we got OpenCL too.

Getting hard to keep track of this alphabet soup.
So where is OpenCL hiding?
In mesa/src/compiler?

Running Khronos' OpenCL-CTS :(

Code: Select all

-- OpenCL hasn't been found!
More stuff to learn, SPIR-V and NIR?
What else is in the Mesa src?
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

User avatar
Akane
Posts: 50
Joined: Tue May 27, 2014 1:20 pm
Location: Tsukuba, Japan

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 12:11 pm

@jamesh We are trying to create py-videocore6, an easy programming environment for VideoCore VI QPU, like the one for VideoCore IV QPU https://github.com/nineties/py-videocore . For now, we have difficulty in using VPM and its DMA. Do you know what values to be fed to the vpmsetup instruction for DMA operations, and how to use stvpm{v,d,p}, vpmwt and vdwwt instructions?

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24162
Joined: Sat Jul 30, 2011 7:41 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 1:26 pm

Akane wrote:
Fri Sep 27, 2019 12:11 pm
@jamesh We are trying to create py-videocore6, an easy programming environment for VideoCore VI QPU, like the one for VideoCore IV QPU https://github.com/nineties/py-videocore . For now, we have difficulty in using VPM and its DMA. Do you know what values to be fed to the vpmsetup instruction for DMA operations, and how to use stvpm{v,d,p}, vpmwt and vdwwt instructions?
I haven't the faintest idea - well outside my knowledge base. I'll pass on to someone who might know.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I think it’s wrong that only one company makes the game Monopoly.” – Steven Wright

User avatar
Akane
Posts: 50
Joined: Tue May 27, 2014 1:20 pm
Location: Tsukuba, Japan

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 2:19 pm

Thanks. I see.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24162
Joined: Sat Jul 30, 2011 7:41 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 2:52 pm

OK, so it appears that the VideoCore6 specifications are not publicly available, so I am afraid I cannot comment on your question with regard to the instructions. You may be able to glean something from the publicly available Mesa driver.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I think it’s wrong that only one company makes the game Monopoly.” – Steven Wright

graphicw
Posts: 91
Joined: Mon Sep 09, 2019 5:04 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 9:20 pm

Might be time for a Chipworks bounty. Lol. A die photo can reveal a lot.

graphicw
Posts: 91
Joined: Mon Sep 09, 2019 5:04 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 9:29 pm

Akane wrote:
Fri Sep 27, 2019 5:03 am
bleep42 wrote:
Tue Sep 10, 2019 12:10 pm
Akane wrote:
Tue Sep 10, 2019 6:23 am
No, nope. The correct theoretical performance of the GPUs is as follows:

VideoCore IV @ 250MHz: 250 [MHz] x 3 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 24 Gflop/s
VideoCore IV @ 300MHz: 300 [MHz] x 3 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 28.8 Gflop/s
VideoCore VI @ 500MHz: 500 [MHz] x 2 [slice] x 4 [qpu/slice] x 4 [processor] x 2 [op/clock] = 32 Gflop/s

That then begs the question, is the 3rd slice still present on the silicon, but not currently enabled in the hardware metal layer, thus allowing for an easy future Pi4+ with 48Gflop/s? ;-)
I know, "no comment"... :-)
As for VC4, there are four slices in the reference manual https://docs.broadcom.com/docs/12358545 p.13, so IMO there actually are four slices on VC4, and one of them is disabled due to yields.
As for VC6, there are two slices per a V3D core https://gist.github.com/phire/6542d2769 ... a0470f45cd , but I have "no comment" how many slices are actually there. However, VC6 can have multiple V3D cores (each core consists of two or so slices). There are relevant register definitions ("Per-V3D-core registers") in https://git.kernel.org/pub/scm/linux/ke ... v3d_regs.h , and the open-source DRM driver states that it only supports single core https://git.kernel.org/pub/scm/linux/ke ... drv.c#n272 . So IMO there may be multiple cores in VC6, and only one of them is enabled due to yields or difficulties in the graphics software stack.
Appears there still could be an option to implement multicore down the road. Question now would be is there another core on hardware not in use or is there an option left open for future iterations of hardware?

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24162
Joined: Sat Jul 30, 2011 7:41 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Sep 27, 2019 9:48 pm

graphicw wrote:
Fri Sep 27, 2019 9:29 pm
Akane wrote:
Fri Sep 27, 2019 5:03 am
bleep42 wrote:
Tue Sep 10, 2019 12:10 pm



That then begs the question, is the 3rd slice still present on the silicon, but not currently enabled in the hardware metal layer, thus allowing for an easy future Pi4+ with 48Gflop/s? ;-)
I know, "no comment"... :-)
As for VC4, there are four slices in the reference manual https://docs.broadcom.com/docs/12358545 p.13, so IMO there actually are four slices on VC4, and one of them is disabled due to yields.
As for VC6, there are two slices per a V3D core https://gist.github.com/phire/6542d2769 ... a0470f45cd , but I have "no comment" how many slices are actually there. However, VC6 can have multiple V3D cores (each core consists of two or so slices). There are relevant register definitions ("Per-V3D-core registers") in https://git.kernel.org/pub/scm/linux/ke ... v3d_regs.h , and the open-source DRM driver states that it only supports single core https://git.kernel.org/pub/scm/linux/ke ... drv.c#n272 . So IMO there may be multiple cores in VC6, and only one of them is enabled due to yields or difficulties in the graphics software stack.
Appears there still could be an option to implement multicore down the road. Question now would be is there another core on hardware not in use or is there an option left open for future iterations of hardware?
It was a long time ago, but I vaguely remember there were some simulations done that showed that the die space that a core takes up was better used for extra cache memory...early Videocore though, may not be relevant, but probably still a worthwhile consideration. Its an interesting tradeoff, more computing blocks, vs making what you have go a lot faster. Goes to show that the path to making GPU's like this faster is not necessarily the obvious one, i.e. throwing more cores at it.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I think it’s wrong that only one company makes the game Monopoly.” – Steven Wright

User avatar
Gavinmc42
Posts: 4049
Joined: Wed Aug 28, 2013 3:31 am

Re: Pi 4 - full specification of VideoCore 6

Sat Sep 28, 2019 12:07 am

As for VC4, there are four slices in the reference manual https://docs.broadcom.com/docs/12358545 p.13, so IMO there actually are four slices on VC4, and one of them is disabled due to yields.
That reference manual seems to be the family reference manual, different part number.
I noticed the 4 quad slices in that family drawing years ago and was told in the BCM2835 there is only 3 quad slices so 12 QPUs.
The VC6 only seems to have 2 slices so 8 QPUs, but they run faster.

I might have missed it, but nothing has ever been said about yield and turning off GPU bits.
OK, so it appears that the VideoCore6 specifications are not publicly available, so I am afraid I cannot comment on your question with regard to the instructions. You may be able to glean something from the publicly available Mesa driver.
Looks like we have to do it the hard way.
By "we" I mean those who have the skills to figure things out, not me :oops:

For those new to Pi's and Videocore's, this is the history
https://github.com/hermanhermitage

The mesa src at least does have the QPU instructions now.
There is a register listing, but is it complete?
At the moment I'm guessing the VC6 has the V3D registers AND the VC4 registers.
Probably a memory dump will confirm that.
I'm dancing on Rainbows.
Raspberries are not Apples or Oranges

User avatar
Akane
Posts: 50
Joined: Tue May 27, 2014 1:20 pm
Location: Tsukuba, Japan

Re: Pi 4 - full specification of VideoCore 6

Sat Sep 28, 2019 12:52 am

jamesh wrote:
Fri Sep 27, 2019 2:52 pm
OK, so it appears that the VideoCore6 specifications are not publicly available, so I am afraid I cannot comment on your question with regard to the instructions. You may be able to glean something from the publicly available Mesa driver.
I've read the Mesa code many times, only to find that Mesa does not use VPM DMA store for now, which makes it impossible to know how to use it.

However, I finally found that the TMU on VC6 can now write to memory in addition to read! Writing a value to TMUD followed by writing an address to TMUA seems to work. Issuing TMUWT instruction seems to make stalls until the TMU operation completes. I cannot test it yet because Raspberry Pi 4 does not pass the compliance test in Japan yet though... https://www.raspberrypi.org/documentati ... formity.md

User avatar
Akane
Posts: 50
Joined: Tue May 27, 2014 1:20 pm
Location: Tsukuba, Japan

Re: Pi 4 - full specification of VideoCore 6

Thu Oct 10, 2019 4:07 pm

So now we have an electromagnetic anechoic box from Micronix, and we are writing GPGPU library for VideoCore VI: https://github.com/Idein/py-videocore6 . It's working very well with simple loops e.g. https://github.com/Idein/py-videocore6/ ... est_qpu.py and should work with more complex codes. We are going to write some BLAS kernels on it after doing some microbenchmarks.

Technocolour
Posts: 55
Joined: Thu Jul 04, 2019 6:23 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Oct 11, 2019 1:38 pm

Akane wrote:
Thu Oct 10, 2019 4:07 pm
So now we have an electromagnetic anechoic box from Micronix, and we are writing GPGPU library for VideoCore VI: https://github.com/Idein/py-videocore6 . It's working very well with simple loops e.g. https://github.com/Idein/py-videocore6/ ... est_qpu.py and should work with more complex codes. We are going to write some BLAS kernels on it after doing some microbenchmarks.
Neat! But what does the Micronix chamber have to do with your GPGPU Python library?

*Ed
Raspberry Pi 4 does not pass the compliance test in Japan yet though...
...

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24162
Joined: Sat Jul 30, 2011 7:41 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Oct 11, 2019 2:25 pm

Cannot give any schedules, Japan is a particularly long winded process requiring lots of documentation changes plus changes to the silk screening on the board. Check out Roger's blog post on the subject.

https://www.raspberrypi.org/blog/compli ... untry-yet/
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I think it’s wrong that only one company makes the game Monopoly.” – Steven Wright

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24162
Joined: Sat Jul 30, 2011 7:41 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Oct 11, 2019 2:30 pm

Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I think it’s wrong that only one company makes the game Monopoly.” – Steven Wright

User avatar
pi-tastic
Posts: 171
Joined: Mon Jul 29, 2019 6:34 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Oct 11, 2019 3:50 pm

So it appears to me, the Graphics Capabilities of this GPU are not even utilized yet.

is there a way one could understand the gpu in this thing simply, like is that equal to an nvidia 8400gs or GMA950 etc?

Sounds like there is 8 core's in this gpu that are not even being utilized at the moment.

I know there is alot of HW engineers and SW engineers on here, you have the ability to explain what
all this means to the rest of us.
maccaps.com - bringing life to dead electronics.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24162
Joined: Sat Jul 30, 2011 7:41 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Oct 11, 2019 4:07 pm

pi-tastic wrote:
Fri Oct 11, 2019 3:50 pm
So it appears to me, the Graphics Capabilities of this GPU are not even utilized yet.

is there a way one could understand the gpu in this thing simply, like is that equal to an nvidia 8400gs or GMA950 etc?

Sounds like there is 8 core's in this gpu that are not even being utilized at the moment.

I know there is alot of HW engineers and SW engineers on here, you have the ability to explain what
all this means to the rest of us.
Er, what? You are almost entirely wrong in everything you have written.

The V3D driver uses the GPU. It uses all the cores of the GPU. What makes you think things are not being used? IIRC, there are 12 (might be 8, cannot remember exactly) cores, known as quads on the VC6. All are used by this driver.

What these guys are doing is bug fixing the driver, adding some bits that are missing, and upgrading it to the next OpenGLES level.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I think it’s wrong that only one company makes the game Monopoly.” – Steven Wright

riccetto80
Posts: 15
Joined: Mon Aug 26, 2019 1:23 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Oct 11, 2019 4:18 pm

jamesh wrote:
Fri Oct 11, 2019 2:30 pm
This is worth a read!

https://www.raspberrypi.org/blog/vc4-an ... an-update/
Amazing! i mean, basically atm raspbian and any other software running on pi4 barely use the gpu, the amount of performance and feature will be added in next months will be massive, for what i understood!

this coupled with the 64bit kernel make me happy i choose a pi4 with 4gb of ram, over a second hand 3b+ :D

keep up the good work devs!!!

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 24162
Joined: Sat Jul 30, 2011 7:41 pm

Re: Pi 4 - full specification of VideoCore 6

Fri Oct 11, 2019 4:22 pm

riccetto80 wrote:
Fri Oct 11, 2019 4:18 pm
jamesh wrote:
Fri Oct 11, 2019 2:30 pm
This is worth a read!

https://www.raspberrypi.org/blog/vc4-an ... an-update/
Amazing! i mean, basically atm raspbian and any other software running on pi4 barely use the gpu, the amount of performance and feature will be added in next months will be massive, for what i understood!

this coupled with the 64bit kernel make me happy i choose a pi4 with 4gb of ram, over a second hand 3b+ :D

keep up the good work devs!!!
Where are people getting the idea that the GPU is barely being used? The driver has been there, in Raspbian, since the Pi4 launch! By default, the desktop uses it! It uses the GPU!! This blog post outlines some bug fixes and improvements that have been made, making it a bit faster and more robust.

So, NO, there won't be massive improvement over the next few months.

There will be incremental improvements as the driver is optimised and bug fixed.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I think it’s wrong that only one company makes the game Monopoly.” – Steven Wright

ShiftPlusOne
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 6084
Joined: Fri Jul 29, 2011 5:36 pm
Location: The unfashionable end of the western spiral arm of the Galaxy

Re: Pi 4 - full specification of VideoCore 6

Fri Oct 11, 2019 4:27 pm

X uses glamor - so it's pretty much all going through the GPU.

https://www.freedesktop.org/wiki/Software/Glamor/

Return to “General discussion”