Live data from Hacker News

On FPGAs as PC Coprocessors (1996)

fpgacpu.org

21–30 of 33 posts

Re: On FPGAs as PC Coprocessors (1996)

#21
I'd think it would be cool to have an FPGA in my PC for various kinds of emulation. If I want to play some old games I can use it for accurate emulation (like the MiSTer project[1]) or if I'm in a DAW and want to produce audio from some old synthesizer I can do that on the FPGA to get a more authentic sound. Likely niche but I'd be all over it.

[1] https://github.com/MiSTer-devel/Main_MiSTer/wiki

Re: On FPGAs as PC Coprocessors (1996)

#22
post #18
post #10

Probably a stupid question: Instead of 6 core or 8 core CPUs, why Intel doesn't make 4 traditional cores + 2 FPGA cores on same die?

It's a good question: the answer is that they have done this. (or atleast they are doing this) https://www.nextplatform.com/2018/05/24/a-peek-inside-that-i... What's proving to be a problem though is where does this fit? If you don't have a clear need for an FPGA then just buy a normal Xeon. If you do need an FPGA then why compromise your Xeon? Have an FPGA card, or hell a group of FPGA cards. The only place this mak…

The TI AM335x CPU has something (sort of) like this...basically 2 microcontrollers that share memory with the ARM cpus.

People have done some pretty clever things with it. Audio processing, driving LED matrix boards, emulating old video boards, driving precision servos, software oscopes and logic analyzers, etc.

Though that's in a small dev board, like the Beaglebone Black, not a beefy Intel server.

Re: On FPGAs as PC Coprocessors (1996)

#23
post #16
post #11

Something I've often dreamed about is an fpga board in pcie card form with a sane toolset along side it so I can treat it as software instead of getting advanced degrees in desktop cable management and I/O pin mapping. Does something like that exist?

What you're describing is OpenCL, yes it exists, both Xilinx and Intel produce toolsets. No they aren't sane by software standards, but they're fantastic compared to hardware engineering. A card will cost you ~$10k for something you'd actually get acceleration from ( https://www.xilinx.com/products/boards-and-kits/alveo/u250.h... ) and you'll still need a degree in electronic engineering to produce something that con…

Most FPGAs that are viable accellerators aren't for hobbyists but they also are not as expensive as you think. I can't find it anymore but I once saw an online shop with a huge variety of 500k+ LUT FPGA modules (just the chip itself on a small PCB) for around 1000€ + 500€ breakoutboard/mainboard. At those prices it makes more sense as an individual to invest into more CPU cores or a GPU (if your problem maps to it).

Edit: Maybe its this one here. https://shop.trenz-electronic.de/de/TE0808-04-06EG-1EE-Ultra...

Re: On FPGAs as PC Coprocessors (1996)

#24
post #4

>So as long as FPGAs are attached on relatively glacially slow I/O buses -- including 32-bit 33 MHz PCI GPUs are on the PCI bus, aren't they? Has something changed in the last two decades to increase bandwidth?

GPUs worked well because you could transfer all your large art assets upfront and then only communicate your mesh and shader logic as the game ran. They don't work so well if you need frequent access to system memory.

They also do not have to send the result back to the CPU because they have a video output directly attached to them.

Re: On FPGAs as PC Coprocessors (1996)

#25
post #18
post #10

Probably a stupid question: Instead of 6 core or 8 core CPUs, why Intel doesn't make 4 traditional cores + 2 FPGA cores on same die?

It's a good question: the answer is that they have done this. (or atleast they are doing this) https://www.nextplatform.com/2018/05/24/a-peek-inside-that-i... What's proving to be a problem though is where does this fit? If you don't have a clear need for an FPGA then just buy a normal Xeon. If you do need an FPGA then why compromise your Xeon? Have an FPGA card, or hell a group of FPGA cards. The only place this mak…

It doesn't have a use case, at least not yet. But easy, cheap gains are running out in general-purpose computing as we near 1nm process. Heterogenous computing will then become more relevant, and a great way to do that is an FPGA.

Re: On FPGAs as PC Coprocessors (1996)

#28
post #16

Earlier quoted context omitted.

What you're describing is OpenCL, yes it exists, both Xilinx and Intel produce toolsets. No they aren't sane by software standards, but they're fantastic compared to hardware engineering. A card will cost you ~$10k for something you'd actually get acceleration from ( https://www.xilinx.com/products/boards-and-kits/alveo/u250.h... ) and you'll still need a degree in electronic engineering to produce something that con…

Most FPGAs that are viable accellerators aren't for hobbyists but they also are not as expensive as you think. I can't find it anymore but I once saw an online shop with a huge variety of 500k+ LUT FPGA modules (just the chip itself on a small PCB) for around 1000€ + 500€ breakoutboard/mainboard. At those prices it makes more sense as an individual to invest into more CPU cores or a GPU (if your problem maps to it).…

How much time would it take to synthesize 500K-lut design on a high-end workstation?

Re: On FPGAs as PC Coprocessors (1996)

#29
The article seems to say FPGA on a high latency bus can only accelerate workload that are streamed via DMA, and implies that a general purpose accelerator has to be closer to the CPU. Sounds like a coprocessor, like putting an FPGA into the slot where the 8087 used to be.

That made me think, why not get even closer? Why not have an FPGA as execution unit? Modern CPUs have multiple ALUs, multiple FPUs, multiple vector units. Wouldn't it be great if an FPGA was added to that, such that the instruction set becomes extensible?

The idea is too obvious to assume nobody ever thought of it. Why isn't it done?

Re: On FPGAs as PC Coprocessors (1996)

#30
post #28

Earlier quoted context omitted.

Most FPGAs that are viable accellerators aren't for hobbyists but they also are not as expensive as you think. I can't find it anymore but I once saw an online shop with a huge variety of 500k+ LUT FPGA modules (just the chip itself on a small PCB) for around 1000€ + 500€ breakoutboard/mainboard. At those prices it makes more sense as an individual to invest into more CPU cores or a GPU (if your problem maps to it).…

How much time would it take to synthesize 500K-lut design on a high-end workstation?

wait, we have an FPGA-based hardware module to accelerate synthetization!

(or even more ironic: an ASIC module)

Post reply on HN