# Whats the difference between an FPGA and an ASIC [closed]

I know what an FPGA and ASIC are.

However what I want to know is what is the difference with cost and time.

• How long does it take to build an FPGA?
• How long does it take to build an ASIC?
• How much does it cost to build an FPGA?
• How much does it cost to build an ASIC?
• How long does it take to program an FPGA?
• How long does it take to program an ASIC?

Knowing this information would really help me understand the difference between these two devices. I would really appreciate it if someone answered this for me.

## closed as off-topic by Marcus Müller, Leon Heller, pipe, uint128_t, Wesley LeeApr 1 '17 at 19:48

• This question does not appear to be about electronics design within the scope defined in the help center.
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• You don't know what an FPGA and an ASIC are. Your questions directly prove that, sorry. Half of them are based on a misunderstanding. – Marcus Müller Apr 1 '17 at 14:23
• I'm voting to close this question as off-topic because the questions are based on a crass misunderstanding of what FPGAs and ASICs are. Explaining that would be far too broad. Please do more research on what FPGAs and ASICs are and how they differ. – Marcus Müller Apr 1 '17 at 14:24
• @MarcusMüller, Agree the question is based on misunderstanding. But I don't think it needs to be closed. Answering these questions will go a long way toward clearing up the misunderstanding about what these two products are. – The Photon Apr 1 '17 at 14:39
• Welcome to the site. Unfortunately for you, this is not a free design house nor an on-line technical encyclopedia, copied out to you on demand. People are more likely to help you if you show that you have gone as far as you can on your own. Please either revise your question or delete it if you find Internet searches give you your answer anyway. Again, welcome. – TonyM Apr 1 '17 at 14:45

How long does it take to build an FPGA?

I'm assuming you mean "fabricate" here, rather than build. The time to fabricate an FPGA is irrelevant to the user in most cases. Since they're all fabricated the same, you can use one available from stock at your distributor or at the factory. In case the factory runs out of stock, it may take 12 to 16 weeks to produce more.

How long does it take to build an ASIC?

I am not an ASIC user, but I guess this is in the range of 12-16 weeks.

How much does it cost to build an FPGA?

Again this is irrelevant to the users. What matters is what it costs to buy an FPGA. This can range from $5 to$5000 depending on the amount of resources in the FPGA.

How much does it cost to build an ASIC?

For the same function, this will be lower than for an FPGA on a per unit basis. However you will have to pay non-recurring engineering (NRE) costs to set up to fabricate a particular ASIC and these might be several hundred thousand dollars or more.

How long does it take to program an FPGA?

If you mean, to create the design for the FPGA, this depends on your skill and the complexity of the design.

If you mean, having created the design, how long to put it into the FPGA, this is typically a few seconds.

How long does it take to program an ASIC?

ASICs aren't programmed. They come from the factory configured to do the function they were designed for.

Note: The word ASIC gets used for many different things. I am assuming you are talking about a traditional "structured ASIC" which has a fixed selection of gates available in the the silicon layers and is configured for a particular function by changing the metal layers that interconnect the gates.

The word "ASIC" is also sometimes used (at least informally in my experience) to refer to fully-custom IC designs, where all layers are free to be modified by the customer. These would require more design effort and higher NRE costs than a structured ASIC.

There are also services that take an FPGA design and convert it to a factory-fixed design (rather than field programmable). I haven't used these services, but I would guess they have lower NRE but higher unit costs than structured ASIC products.

• @DaveTweed, with my added note in mind specifying that I'm talking about structured ASICs, not full custom, is 100's of thousands in NRE still expected, or is 10's of thousands more likely? – The Photon Apr 1 '17 at 14:48
• I'm really not sure myself. But knowing that the mask charges for a large design in a modern process can run into the millions of dollars, I wanted to set a more realistic expectation for the OP. This is otherwise a great answer. – Dave Tweed Apr 1 '17 at 14:52
• Note that I'm no expert in the field of supply chain management and made all these words up, but that doesn't stop them from being valid, understandable, semantically relatively clear, German words. Wort·zu·sam·men·setz·ungs·fäh·ig·keit (word composition capability, 9 syllables) is one of German's strengths. – Marcus Müller Apr 1 '17 at 16:32
• @MarcusMüller even if you aren't a military customer you can easily spend $15k+ on the top of the range. Larger Stratix V's for example are$13k each in low quantities. – Tom Carpenter Apr 1 '17 at 17:15
• @MarcusMüller how about FPGAskönnenschrecklichteuersein (I know nothing of German, so blame Google Translate ;)) – Tom Carpenter Apr 1 '17 at 17:28