8 ms·

Gnomes per second in Vulkan and OpenGL ES

96 points by alexvoica 11y ago

Drakim 11y ago
When it says "Vulkan driver for PowerVR Rogue GPUs", does that mean I can only use Vulkan when the user has a GPU that supports it? ...Because that sounds like it could be a really long wait, if it happens at all. I guess it could work for the gaming console market?
- AndrewDucker 11y ago
  You'll need a card with Vulkan drivers. But as it has support from NVidia and AMD that won't be a problem: https://www.khronos.org/news/press/khronos-reveals-vulkan-api-for-high-efficiency-graphics-and-compute-on-gpus https://www.khronos.org/news/press/khronos-reveals-vulkan-ap... (See the "Industry Support" section.)
- robmaister 11y ago
  Vulkan is designed for modern GPUs, not the other way around. You would only have to wait for GPU vendors to write a new driver for their existing cards. NVIDIA, AMD, and a bunch of other large players are part of the Khronos Group designing Vulkan, so I wouldn't be surprised to see desktop/laptop GPU drivers a few weeks after the release of the finalized specification. The only place you probably won't see a quick uptake is with mobile GPUs, since they essentially never receive updates.
  - dr_zoidberg 11y ago
    The post specifically targets a mobile GPU. Relevant links: [1] https://en.wikipedia.org/wiki/PowerVR#Series_6_.28Rogue.29 https://en.wikipedia.org/wiki/PowerVR#Series_6_.28Rogue.29 [2] http://anandtech.com/show/7335/the-iphone-5s-review/7 http://anandtech.com/show/7335/the-iphone-5s-review/7
    - simoncion 11y ago
      While true, that doesn't invalidate robmaister's point. If mobile GPUs as a class almost never receive updates, this will slow adoption of a new low-level way of using them, regardless of a few scattered exceptions to the "Mobile GPUs never receive updates" rule. :)
      - dr_zoidberg 11y ago
        Yes, you don't "upgrade" your mobile phones GPU (or any hardware except the SD card), but many people change their smartphone yearly (and sometimes faster). So there's the "upgrade path" for mobile GPUs. I actually find it amusing that a phone or tablet with a new SoC has a "better" GPU than my 3 year old Core i3.
        simoncion 11y ago
        I said "update" as in "software update", not "upgrade" as in "hardware upgrade". As I understand it (and I may not understand it well, as I don't do this for a living), SoC vendors are primarily in the business of selling hardware, rather than software. Everything that follows is second-hand information. Often, folks who want an SDK for that SoC get the hardware, a bunch of blobs to run the hardware, and a particular version of an OS to run the blobs and any ancillary software. Given that the vendor is a hardware manufacturer, you're not infrequently forever stuck with whatever blobs and version of the OS you were handed. (Unless -of course- you can do the dev work on the OS or blobs yourself.) This lack of focus by the vendor on the software side of things implies that -say- interesting new graphics APIs are only available on the newest hardware. Even if the SoC vendor does do the work to port said API to their older hardware, the folks who used that hardware may not want or be able to verify their software with the new stuff from the vendor.
        alexvoica 11y ago
        This is how an software update works in mobile: the GPU vendor writes the driver using a spec (e.g. Vulkan), then submits the driver for conformance testing with Khronos. Once the driver achieves conformance, the driver is made available to chip makers and OEMs. They take the driver and build an Android BSP; the new ROM is then pushed to consumers through an OTA. The GPU vendor has little control or influence over the update process beyond the point of providing the driver.
- Narishma 11y ago
  Consoles don't need Vulkan, since they've always had low-level (or non-existant) graphics APIs.
Am-hehu 11y ago
I would like to excuse for my incompetent/ignorant comment in advance, but wouldn't it be fairer to compare Vulkan with OpenGL 4.5 where indirect indexed draw calls are available? I also noticed that this demo avoids interactive animations (moving / reacting objects). In my experience with next-gen apis this results often in command dead-locks and inevitable queue-rollbacks.
- simcop2387 11y ago
  Not necessarily, I believe they're demoing this against OpenGL ES specifically because of google recently announcing that Vulkan will be available on android[1]. Given the 4 cores that seems to line up, since a lot of ARM devices are going to multicore recently. [1] http://arstechnica.com/gadgets/2015/08/android-to-support-vulkan-graphics-api-the-open-answer-to-metal-and-dx12/ http://arstechnica.com/gadgets/2015/08/android-to-support-vu...
- kllrnohj 11y ago
  The GPU in question here, the PowerVR G6430, does not support OpenGL 4.5. It tops out at OpenGL 3.2 since it's a mobile part so everyone is using GLES. The blog post only somewhat touches on it but I believe a key part of why this is so much faster is that it sounds like Vulkan is actually exposing tiled-based rendering. Note that PowerVR is a tile-based deferred renderer under the hood[1]. So if the app is doing the work of chunking draws into tiles instead of the driver trying to extract that from the OpenGL stream that's going to be significantly more efficient. 1: http://blog.imgtec.com/powervr/a-look-at-the-powervr-graphics-architecture-tile-based-rendering http://blog.imgtec.com/powervr/a-look-at-the-powervr-graphic...
  - olaulaja 11y ago
    Vulkan doesnt really expose tile based rendering. In the demo the scene is split into tiles and since the geometry is static they can prepare commands for gpu execution once for each of these tiles. This cannot be done in OpenGL which effectively has to repeat this work every frame (the driver hides this) There are of course other tricks to speed up crowds like this in OpenGL
10098 11y ago
Is the Vulkan spec out already? Where can I get it?
- kllrnohj 11y ago
  Nope. The API is still in development.
- tsomctl 11y ago
  AMD has released a specification for Mantle, which is the predecessor of Vulkan: http://www.amd.com/Documents/Mantle-Programming-Guide-and-API-Reference.pdf http://www.amd.com/Documents/Mantle-Programming-Guide-and-AP... There is also a demo and sdk for Mantle here: https://github.com/Overv/MantleHelloTriangle https://github.com/Overv/MantleHelloTriangle
raverbashing 11y ago
So, what are the chances of Vulkan drivers from devices makers "follow the tradition" of their OpenGL drivers and only implement half the spec with lots of bugs and lack of functionality
- DominikD 11y ago
  High if Khronos doesn't provide a comprehensive certification suite. Dunno what's the status for Vulkan, but OGL/OGLES versus D3D (any feature level) is a joke. :S
- _pmf_ 11y ago
  > So, what are the chances of Vulkan drivers from devices makers "follow the tradition" of their OpenGL drivers and only implement half the spec with lots of bugs and lack of functionality I'd say in the high 99.99999ies
- ska 11y ago
  Hard to say yet, but since one of the design goals of Vulkan is to address this very issue, it seems inept to assume they can't/won't improve things w.r.t drivers before there is evidence.
- Jasper_ 11y ago
  Vulkan is extraordinarily thin. There really isn't the large complex global state machine that OpenGL has -- the potential for complex bugs are a lot less.
  - raverbashing 11y ago
    I agree, that's what I hope, but we never know...
  - runeks 11y ago
    Good point. Vulkan's purpose is for GPU hardware companies to stop having to write graphics software (drivers). GPU producers shouldn't be responsible for writing OpenGL compilers any more than AMD and Intel should be responsible for writing C/C++ compilers and Python VMs. As I understand it, the goal is to move the API closer to the hardware. Hopefully so close that the driver will be very thin. There are plenty of software developers out there who can implement an OpenGL driver in Vulkan as well as the employees of AMD and Nvidia, I would think.
justabystander 11y ago
Any progress on getting OSS drivers for the PowerVR prodcut family? Security demands I keep an updated system, but that's not really practical with closed-source drivers.

96 points by alexvoica 11y ago

When it says "Vulkan driver for PowerVR Rogue GPUs", does that mean I can only use Vulkan when the user has a GPU that supports it? ...Because that sounds like it could be a really long wait, if it happens at all. I guess it could work for the gaming console market?

AndrewDucker 11y ago
You'll need a card with Vulkan drivers. But as it has support from NVidia and AMD that won't be a problem: https://www.khronos.org/news/press/khronos-reveals-vulkan-api-for-high-efficiency-graphics-and-compute-on-gpus https://www.khronos.org/news/press/khronos-reveals-vulkan-ap... (See the "Industry Support" section.)
robmaister 11y ago
Vulkan is designed for modern GPUs, not the other way around. You would only have to wait for GPU vendors to write a new driver for their existing cards. NVIDIA, AMD, and a bunch of other large players are part of the Khronos Group designing Vulkan, so I wouldn't be surprised to see desktop/laptop GPU drivers a few weeks after the release of the finalized specification. The only place you probably won't see a quick uptake is with mobile GPUs, since they essentially never receive updates.
- dr_zoidberg 11y ago
  The post specifically targets a mobile GPU. Relevant links: [1] https://en.wikipedia.org/wiki/PowerVR#Series_6_.28Rogue.29 https://en.wikipedia.org/wiki/PowerVR#Series_6_.28Rogue.29 [2] http://anandtech.com/show/7335/the-iphone-5s-review/7 http://anandtech.com/show/7335/the-iphone-5s-review/7
  - simoncion 11y ago
    While true, that doesn't invalidate robmaister's point. If mobile GPUs as a class almost never receive updates, this will slow adoption of a new low-level way of using them, regardless of a few scattered exceptions to the "Mobile GPUs never receive updates" rule. :)
    - dr_zoidberg 11y ago
      Yes, you don't "upgrade" your mobile phones GPU (or any hardware except the SD card), but many people change their smartphone yearly (and sometimes faster). So there's the "upgrade path" for mobile GPUs. I actually find it amusing that a phone or tablet with a new SoC has a "better" GPU than my 3 year old Core i3.
      - simoncion 11y ago
        I said "update" as in "software update", not "upgrade" as in "hardware upgrade". As I understand it (and I may not understand it well, as I don't do this for a living), SoC vendors are primarily in the business of selling hardware, rather than software. Everything that follows is second-hand information. Often, folks who want an SDK for that SoC get the hardware, a bunch of blobs to run the hardware, and a particular version of an OS to run the blobs and any ancillary software. Given that the vendor is a hardware manufacturer, you're not infrequently forever stuck with whatever blobs and version of the OS you were handed. (Unless -of course- you can do the dev work on the OS or blobs yourself.) This lack of focus by the vendor on the software side of things implies that -say- interesting new graphics APIs are only available on the newest hardware. Even if the SoC vendor does do the work to port said API to their older hardware, the folks who used that hardware may not want or be able to verify their software with the new stuff from the vendor.
        alexvoica 11y ago
        This is how an software update works in mobile: the GPU vendor writes the driver using a spec (e.g. Vulkan), then submits the driver for conformance testing with Khronos. Once the driver achieves conformance, the driver is made available to chip makers and OEMs. They take the driver and build an Android BSP; the new ROM is then pushed to consumers through an OTA. The GPU vendor has little control or influence over the update process beyond the point of providing the driver.
Narishma 11y ago
Consoles don't need Vulkan, since they've always had low-level (or non-existant) graphics APIs.

Am-hehu 11y ago

I would like to excuse for my incompetent/ignorant comment in advance, but wouldn't it be fairer to compare Vulkan with OpenGL 4.5 where indirect indexed draw calls are available? I also noticed that this demo avoids interactive animations (moving / reacting objects). In my experience with next-gen apis this results often in command dead-locks and inevitable queue-rollbacks.

simcop2387 11y ago
Not necessarily, I believe they're demoing this against OpenGL ES specifically because of google recently announcing that Vulkan will be available on android[1]. Given the 4 cores that seems to line up, since a lot of ARM devices are going to multicore recently. [1] http://arstechnica.com/gadgets/2015/08/android-to-support-vulkan-graphics-api-the-open-answer-to-metal-and-dx12/ http://arstechnica.com/gadgets/2015/08/android-to-support-vu...
kllrnohj 11y ago
The GPU in question here, the PowerVR G6430, does not support OpenGL 4.5. It tops out at OpenGL 3.2 since it's a mobile part so everyone is using GLES. The blog post only somewhat touches on it but I believe a key part of why this is so much faster is that it sounds like Vulkan is actually exposing tiled-based rendering. Note that PowerVR is a tile-based deferred renderer under the hood[1]. So if the app is doing the work of chunking draws into tiles instead of the driver trying to extract that from the OpenGL stream that's going to be significantly more efficient. 1: http://blog.imgtec.com/powervr/a-look-at-the-powervr-graphics-architecture-tile-based-rendering http://blog.imgtec.com/powervr/a-look-at-the-powervr-graphic...
- olaulaja 11y ago
  Vulkan doesnt really expose tile based rendering. In the demo the scene is split into tiles and since the geometry is static they can prepare commands for gpu execution once for each of these tiles. This cannot be done in OpenGL which effectively has to repeat this work every frame (the driver hides this) There are of course other tricks to speed up crowds like this in OpenGL

10098 11y ago

Is the Vulkan spec out already? Where can I get it?

kllrnohj 11y ago
Nope. The API is still in development.
tsomctl 11y ago
AMD has released a specification for Mantle, which is the predecessor of Vulkan: http://www.amd.com/Documents/Mantle-Programming-Guide-and-API-Reference.pdf http://www.amd.com/Documents/Mantle-Programming-Guide-and-AP... There is also a demo and sdk for Mantle here: https://github.com/Overv/MantleHelloTriangle https://github.com/Overv/MantleHelloTriangle

raverbashing 11y ago

So, what are the chances of Vulkan drivers from devices makers "follow the tradition" of their OpenGL drivers and only implement half the spec with lots of bugs and lack of functionality

DominikD 11y ago
High if Khronos doesn't provide a comprehensive certification suite. Dunno what's the status for Vulkan, but OGL/OGLES versus D3D (any feature level) is a joke. :S
_pmf_ 11y ago
> So, what are the chances of Vulkan drivers from devices makers "follow the tradition" of their OpenGL drivers and only implement half the spec with lots of bugs and lack of functionality I'd say in the high 99.99999ies
ska 11y ago
Hard to say yet, but since one of the design goals of Vulkan is to address this very issue, it seems inept to assume they can't/won't improve things w.r.t drivers before there is evidence.
Jasper_ 11y ago
Vulkan is extraordinarily thin. There really isn't the large complex global state machine that OpenGL has -- the potential for complex bugs are a lot less.
- raverbashing 11y ago
  I agree, that's what I hope, but we never know...
- runeks 11y ago
  Good point. Vulkan's purpose is for GPU hardware companies to stop having to write graphics software (drivers). GPU producers shouldn't be responsible for writing OpenGL compilers any more than AMD and Intel should be responsible for writing C/C++ compilers and Python VMs. As I understand it, the goal is to move the API closer to the hardware. Hopefully so close that the driver will be very thin. There are plenty of software developers out there who can implement an OpenGL driver in Vulkan as well as the employees of AMD and Nvidia, I would think.

justabystander 11y ago

Any progress on getting OSS drivers for the PowerVR prodcut family? Security demands I keep an updated system, but that's not really practical with closed-source drivers.