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Developer Preview – EC2 Instances with Programmable Hardware

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Re: Developer Preview – EC2 Instances with Programmable Hardware

#191

Post by fpgaminer »

al2o3cr wrote: post #182
deafcalculus wrote: post #167

Earlier quoted context omitted.

What can each one of those 2.5 million "logic elements" do? Last time I used an FPGA, they were mostly made up of 4-bit LUTs. How many NOT operations can this do per cycle (and per second)? I realise FPGAs aren't the most suited for this, but the raw number is useful when thinking about how much better the FPGA is compared to a GPU for simple ops.

The metrics have gotten pretty opaque since the old days when an FPGA was a "sea of LUTs" all alike; modern ones include a ton of (semi-)fixed function hardware like multiply-accumulate blocks and embedded dual-port RAM. Even the LUTs themselves can be reprogrammed into small RAM blocks or shift registers, so counting "logic elements" is mostly a marketing exercise.

While yes the architectures have become more "CISC-like", they aren't particularly convoluted or opaque. It's pretty easy to describe the architectures and come up with numbers for them. Xilinx could literally just say, "1 Million 6-to-2 LUTs" and that would be entirely transparent and helpful.

So it's not so much changes in architecture that have given rise to the translucency of these numbers. It's a measuring contest between Xilinx and IntelFPGA who believe you need to present bigger numbers in marketing material to win engineers. I can't speak for other FPGA engineers, but personally it just frustrates me and wastes my time. I don't ever take those numbers at face value, and I wouldn't hire anyone who did. Xilinx is the worst offender here. At least IntelFPGA will often quote their parts both in transparent terms (# of ALMs) and useful comparisons (# of equivalent LEs). I've never seen them pull a completely made up "System Logic Cell" out of thin air.

Re: Developer Preview – EC2 Instances with Programmable Hardware

#193

Post by aseipp »

makapuf wrote: post #180
cottonseed wrote: post #110

Earlier quoted context omitted.

This is so awesome, I can't even. I wrote arachne-pnr [0] to learn about FPGAs to get ready for this day. Just signed up, can't way to play with these! I hope the growing popularity of FPGAs for general-purpose computing will help push the vendors to open up bitstreams and invest in open-source design tools. [0] https://github.com/cseed/arachne-pnr

Wow Clifford is that you ? I hope this, exciting as it may be, won't make you leave open fpga efforts for the dark side (saw your talk last Fosdem, was very exciting)

Cotton is the author of arachne-pnr. Clifford is the author of Yosys and IceStorm, which are all separate projects. Not the same person.

FWIW, Clifford has recently started reversing the bits of the modern Xilinx FPGA series. So, stay tuned for a Xilinx IceStorm-equivalent sometime down the road (a few years, probably...)

Re: Developer Preview – EC2 Instances with Programmable Hardware

#194

Post by alexforencich »

lisper wrote: post #161

Newbie question: What do verilog and VHDL compile down to, i.e. what is the assembly/machine language for FPGAs?

Binary FPGA configuration instructions - block RAM contents, routing switch configruation, register configuration an initial state, PLL/DCM configuration, and of course LUT contents. That's the final result of the toolchain, ready to get sent to the FPGA via JTAG or written into a configuration flash chip. It's the FPGA equivalent of machine code.

For the higher level object file or assembly language, that would be a netlist - essentially a digital representation of a schematic. The HDL is transformed into a netlist, then the netlist is optimized and the components converted from generics to device-specifc components, then the placement and routing is determined, and finally a 'bit' file is generated for actually configuring the FPGA. This process can take several hours for a large design.

Re: Developer Preview – EC2 Instances with Programmable Hardware

#196

Post by matt_d »

technological wrote: post #19

Quick Question: If anyone wants to learn programming an FPGA is learning C only way to go ? how hard is to learn and program in verilog/VHDL without electrical background ? If anyone suggests links or books, please do Thank You

Here's a collection of get-started resources: http://tinyurl.com/fpga-resources

You can start with the EDA Playground tutorial, practice with HDLBits, while going through a book alongside (e.g., Harris & Harris) for examples, exercises, and best practices.

Similarly to a sibling thread, I'd also go with a free and open source flow, IceStorm (for the cheaply available iCE40 FPGAs): http://www.clifford.at/icestorm/

You can follow-up from the aforementioned tutorial and continue testing the designs on an iCE40 board -- starting here: http://hackaday.com/2015/08/19/learning-verilog-on-a-25-fpga...

Here are some really great presentations about it (slides & videos) by the creator (which can also serve in part as a general introduction):

- http://www.clifford.at/papers/2015/icestorm-flow/

- http://www.clifford.at/papers/2015/yosys-icestorm-etc/

Have fun!

Re: Developer Preview – EC2 Instances with Programmable Hardware

#197

Post by alexforencich »

Ceriand wrote: post #124

Is there direct DMA access to/from the network interface bypassing the CPU?

Doesn't look like it from the article. That could be very interesting, but there could be network architecture constraints that prevent Amazon from providing that from the get-go. And it wouldn't be used in all cases, so that could burn a lot of switch ports. Seems like they're targeting more compute offload and less network appliance.

Re: Developer Preview – EC2 Instances with Programmable Hardware

#198

Post by koolba »

dx034 wrote: post #174
koolba wrote: post #35

Just wait till this gets combined with Lambda.

How would they do that? Since the FPGAs are not shared, I don't see how you could use it for very short-lived instances.

If the spin up time is fast enough then they could do it. Alternatively if it's active enough then there would a stream of requests processed by the same, already loaded, FPGA.

Re: Developer Preview – EC2 Instances with Programmable Hardware

#199

Post by ktta »

alexforencich wrote: post #192
ktta wrote: post #75

If anyone is wondering how the FPGA board looks like https://imgur.com/a/wUTIp

Are they actually using that one, or is that just a board that happens to have that particular FPGA on it?

The FPGA in the image is the retail version. But it's more than likely that amazon is using the same one since they don't modify the GPUs although they purchase them on a much larger scale.

Re: Developer Preview – EC2 Instances with Programmable Hardware

#200

Post by cottonseed »

makapuf wrote: post #180
cottonseed wrote: post #110

Earlier quoted context omitted.

This is so awesome, I can't even. I wrote arachne-pnr [0] to learn about FPGAs to get ready for this day. Just signed up, can't way to play with these! I hope the growing popularity of FPGAs for general-purpose computing will help push the vendors to open up bitstreams and invest in open-source design tools. [0] https://github.com/cseed/arachne-pnr

Wow Clifford is that you ? I hope this, exciting as it may be, won't make you leave open fpga efforts for the dark side (saw your talk last Fosdem, was very exciting)

No, Clifford is cliffordvienna on HN. He wrote Yosys (and amazing piece of software) and did the iCE40 reverse engineering (amazing work). I wrote the place and router, arachne-pnr.
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