3 ms·

Depending on the price, this will be interesting for I/do-something/O workloads like video encoding/decoding. Depending on the price, looking forward to it. Of

Depending on the price, this will be interesting for I/do-something/O workloads like video encoding/decoding. Depending on the price, looking forward to it. Of course, depending on the price. :)

thesz 8y ago
You won't have enough resources for video encoding, most probably. Arria 10 FPGA has 67M bits of memory total (8.5M bytes), including one simulated with registers. As far as I remember, just storing 1920x1080 (HD) frame in 4:2:0 mode would require 4M bytes, half of memory. 4K would require 4 times as much resources. You may do some on-line processing like running neural net on the video content, but that's about it. Don't expect anything super exciting from that chip. Yet, it will bring joy to high frequency traders. The systems there do most of the work in FPGA, including UDP/TCP/IP packets processing and offload some work to CPU (broadcasts about network topology are handled on CPU, for example). They also would like to receive CPU computation results as fast as they can and this chip is exactly that.
- pjc50 8y ago
  You have more than enough resources for video encoding, because all modern codecs have a macroblock structure. You don't need to keep the whole current frame in at once, you can slide a window around it. (Conversely, you do need to keep the matching area of the previous frame and maybe even the next frame in order to do proper inter-prediction). That said I would assume GPUs are more suited to this task. By FPGA standards this thing is enormous.
  - thesz 8y ago
    You are also limited by number of access paths into the memory which holds, say, macroblock. I forgot about this issue, sorry. For block RAM in previous generation FPGAs from Altera there were one read and one write paths. To have two read paths you would need to copy block RAM as many times as you need read paths. This means that if you search for block content inside a macroblock with N parallel accesses you would need N copies of macroblock stored. Tabula's time shifting tech allowed for up to, I believe, twelve paths into the block RAM, six for read and six for write (they were time-scheduled to 1-read-1-write block RAM operating at six times the frequency). I thought this thing would be a road for superscalar FPGA CPUs, but Tabula was closed. You can imagine not using RAM at all, but then you will spend other resources in FPGA. These are problems with video compression I see here. I think they are substantial but not unsurmountable and require a balance to solve. It is just me that I saw the balance is not in favour of FPGA.
    - fezz 8y ago
      Depends alot on the codec too. Light weight codecs like Tico/jpeg-xs and some jpeg implementations can use very little ram (~12 rows worth). Others need alot more for rate control, motion estimation, etc.
    - cbHXBY1D 8y ago
      Such a shame that Tabula closed down. They had some of the most interesting tech -- hopefully someone is able to pick it up someday. As someone who works with FPGAs, I think a solution like theirs is the only way FPGAs will become mainstream.
      - nxmehta 8y ago
        Altera took many of the employees (although quite a few are now at AWS) and it's rumored they also bought the IP. A lot of the core ideas will live on in Stratix, hopefully.

Depending on the price, this will be interesting for I/do-something/O workloads like video encoding/decoding. Depending on the price, looking forward to it. Of course, depending on the price. :)

thesz 8y ago

You won't have enough resources for video encoding, most probably. Arria 10 FPGA has 67M bits of memory total (8.5M bytes), including one simulated with registers. As far as I remember, just storing 1920x1080 (HD) frame in 4:2:0 mode would require 4M bytes, half of memory. 4K would require 4 times as much resources. You may do some on-line processing like running neural net on the video content, but that's about it. Don't expect anything super exciting from that chip. Yet, it will bring joy to high frequency traders. The systems there do most of the work in FPGA, including UDP/TCP/IP packets processing and offload some work to CPU (broadcasts about network topology are handled on CPU, for example). They also would like to receive CPU computation results as fast as they can and this chip is exactly that.

pjc50 8y ago
You have more than enough resources for video encoding, because all modern codecs have a macroblock structure. You don't need to keep the whole current frame in at once, you can slide a window around it. (Conversely, you do need to keep the matching area of the previous frame and maybe even the next frame in order to do proper inter-prediction). That said I would assume GPUs are more suited to this task. By FPGA standards this thing is enormous.
- thesz 8y ago
  You are also limited by number of access paths into the memory which holds, say, macroblock. I forgot about this issue, sorry. For block RAM in previous generation FPGAs from Altera there were one read and one write paths. To have two read paths you would need to copy block RAM as many times as you need read paths. This means that if you search for block content inside a macroblock with N parallel accesses you would need N copies of macroblock stored. Tabula's time shifting tech allowed for up to, I believe, twelve paths into the block RAM, six for read and six for write (they were time-scheduled to 1-read-1-write block RAM operating at six times the frequency). I thought this thing would be a road for superscalar FPGA CPUs, but Tabula was closed. You can imagine not using RAM at all, but then you will spend other resources in FPGA. These are problems with video compression I see here. I think they are substantial but not unsurmountable and require a balance to solve. It is just me that I saw the balance is not in favour of FPGA.
  - fezz 8y ago
    Depends alot on the codec too. Light weight codecs like Tico/jpeg-xs and some jpeg implementations can use very little ram (~12 rows worth). Others need alot more for rate control, motion estimation, etc.
  - cbHXBY1D 8y ago
    Such a shame that Tabula closed down. They had some of the most interesting tech -- hopefully someone is able to pick it up someday. As someone who works with FPGAs, I think a solution like theirs is the only way FPGAs will become mainstream.
    - nxmehta 8y ago
      Altera took many of the employees (although quite a few are now at AWS) and it's rumored they also bought the IP. A lot of the core ideas will live on in Stratix, hopefully.