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I'll bite: In which way is a computation engine (CPU [not ASIC], GPU [ASIC], Xeon Phi [ASIC]) more general purpose than a computation engine for AI [ASIC], GPU

by dom0 10y ago

I'll bite: In which way is a computation engine (CPU [not ASIC], GPU [ASIC], Xeon Phi [ASIC]) more general purpose than a computation engine for AI [ASIC], GPU [ASIC] or Xeon Phi [ASIC, even though some of these are usable as a host processor?] For other parts it's even less clear: Flash or hard drive controllers are pretty normal micros with some dedicated hardware bolted on - clearly ASIC, but most of it was not designed for the "AS" part, and you could just ignore the flash and SATA interfaces and use it as a regular micro. So the distinction, if any, can't be about volume (since a lot of them are large volume parts), nor about functionality, but some fuzzy distinction by narrowness of intended use of the part (- but then again, GPUs). And how does it apply to other domains of chips? Is a TDA7000 an ASIC? :)

Cyph0n 10y ago
Firstly, on what basis are the Xeon Phi and GPUs ASICs? Secondly, I'd argue that a GPU is definitely more general-purpose than the TPU. Just look at the block diagram shown in the linked paper: a GPU is orders of magnitude more complex than that! The added complexity is a result of a GPU having to support a wider variety of workloads. As for Flash controllers etc., if they incorporate a MCU or CPU, then they are simply not ASICs? I believe that the term ASIC itself is quite overloaded. From what I've seen, many people use the term ASIC to refer to any IC that is not reconfigurable (i.e., FPGA). Going by that definition, an ASIC is any circuit that is custom designed and fabbed on a wafer. Naturally, this would include a CPU, a GPU, and whatever else you can think of. The way I like to think of it is that an ASIC is a circuit designed to perform a specific task as efficiently as possible. Note that I used to word circuit; in other words, an ASIC could be part of some larger design. Some examples off the top of my head: - Digital camera CMOS sensor - Video decryption chip (e.g., in a cable box) - Active noise cancellation chip (if custom and not a DSP) - Full-custom TPM - Full-custom RSA-2048 engine - High-performance Ethernet switch controller - CPU cache controller (ASIC that is part of a CPU)
- dom0 10y ago
  Counterpoint to complexity: Simple CPUs (scalar, in-order) are likely less complex than the TPU. E.g. here's a super-scalar in-order core: https://patentimages.storage.googleapis.com/US6311261B1/US06311261-20011030-D00011.png https://patentimages.storage.googleapis.com/US6311261B1/US06... > I believe that the term ASIC itself is quite overloaded. I think we're arguing the same thing, just from different angles :)

by dom0 10y ago

Cyph0n 10y ago

Firstly, on what basis are the Xeon Phi and GPUs ASICs? Secondly, I'd argue that a GPU is definitely more general-purpose than the TPU. Just look at the block diagram shown in the linked paper: a GPU is orders of magnitude more complex than that! The added complexity is a result of a GPU having to support a wider variety of workloads. As for Flash controllers etc., if they incorporate a MCU or CPU, then they are simply not ASICs? I believe that the term ASIC itself is quite overloaded. From what I've seen, many people use the term ASIC to refer to any IC that is not reconfigurable (i.e., FPGA). Going by that definition, an ASIC is any circuit that is custom designed and fabbed on a wafer. Naturally, this would include a CPU, a GPU, and whatever else you can think of. The way I like to think of it is that an ASIC is a circuit designed to perform a specific task as efficiently as possible. Note that I used to word circuit; in other words, an ASIC could be part of some larger design. Some examples off the top of my head: - Digital camera CMOS sensor - Video decryption chip (e.g., in a cable box) - Active noise cancellation chip (if custom and not a DSP) - Full-custom TPM - Full-custom RSA-2048 engine - High-performance Ethernet switch controller - CPU cache controller (ASIC that is part of a CPU)

dom0 10y ago
Counterpoint to complexity: Simple CPUs (scalar, in-order) are likely less complex than the TPU. E.g. here's a super-scalar in-order core: https://patentimages.storage.googleapis.com/US6311261B1/US06311261-20011030-D00011.png https://patentimages.storage.googleapis.com/US6311261B1/US06... > I believe that the term ASIC itself is quite overloaded. I think we're arguing the same thing, just from different angles :)