9 ms·

The raw cost of the coreplex's silicon is probably ~7 cents. of course there's extra stuff that goes into a soc, but why do you assume it will go from 7 cents t

• pdq 9y ago
  You have to take into account the end product, not just raw silicon cost. There are costs in SoC packaging, wire bonding, testing, yield loss, warehousing, distribution, R&D, and profit.
• pjc50 9y ago
  Since when have the silicon costs been the slightest bit relevant to IC pricing? It's all about volume and recouping R&D costs and other NRE.
  • monocasa 9y ago
    Yeah, but this core is open source, which significantly reduces the NRE costs for most integrators.
    • pjc50 9y ago
      It looks like (although not 100% clear) it's available as hard IP, which means they've done the layout, but the very expensive mask NRE remains. (They have a plan for an actual SOC but aren't shipping yet: https://www.sifive.com/documentation/freedom-soc/freedom-u500-platform-brief/ https://www.sifive.com/documentation/freedom-soc/freedom-u50... )
    • opencl 9y ago
      The RISC-V ISA is free (i.e. you can design your own core without paying royalties to a company like ARM, which is what SiFive has done here) but this is a normal paid-for IP core. They do have some SoCs with a "free and open platform specification" but there's no public repo to download their Verilog code from. If you want an actual open source RISC-V core, see: https://github.com/lowRISC/lowrisc-chip https://github.com/lowRISC/lowrisc-chip
      • monocasa 9y ago
        The source here isn't their core? https://github.com/sifive/freedom https://github.com/sifive/freedom
        • opencl 9y ago
          That code seems to be for an FPGA devkit for their SoC but using an entirely different CPU core, the Berkeley Rocket Chip. They're selling coreplex licenses for several hundred thousand dollars (not the one in the linked product page, it isn't for sale yet): https://dev.sifive.com/coreplex-risc-v-ip/buy/rtl/e51_coreplex/configure/ https://dev.sifive.com/coreplex-risc-v-ip/buy/rtl/e51_corepl...
          • monocasa 9y ago
            SiFive is a bunch of Berkeley people. Are you totally sure that their cores aren't rebranded Rocket cores?
          • _chris_ 9y ago
            > using an entirely different CPU core, the Berkeley Rocket Chip Nope, the U54 and E31 are both Rocket, just with different parameters/configurations. SiFive has continued to improve Rocket and contribute their improvements back to the available source code.
      • asb 9y ago
        Hi, I'm one of the co-founders of the lowRISC project. You're right that SiFive's licensing arrangements can be somewhat confusing. Although they sell licenses (like https://static.dev.sifive.com/business/sifive-license-and-support-agreement-sample-e51-20170602.pdf https://static.dev.sifive.com/business/sifive-license-and-su...) which look like a typical proprietary IP agreement, the SiFive Coreplex IP is a derivative of the open-source Rocket chip generator. SiFive was founded by a team from Berkeley who produced Rocket, and are almost certainly now the biggest contributor to ongoing Rocket development.
        • 9y ago
  • topspin 9y ago
    This discussion brings to mind something Gordon Moore explained[1] about the economics of chip fabrication. According to this Intel co-founder it's all about selling silicon real-estate: What we end up doing is really selling real estate. We've sold area on the silicon wafer for about a billion dollars an acre, that order of magnitude, as long as I've been in the industry. Individual transistors used to sell for a few billion dollars an acre. The microprocessors today, too. Maybe DRAMs are something under a billion. So the cost of fabricating a wafer full of devices doesn't change much over time, but shrinking features means you get more devices for that cost. Notice the difference he points out between microprocessors and DRAM: all the costs involved with highly complex devices like CPUs ultimately still fall within the same order of magnitude as the cost of simple DRAM devices. The cost is some small number of "billions per acre" whether you're making the latest cutting edge circuit or just more arrays of bits. [1] https://www.intel.com/pressroom/archive/speeches/gem93097.htm https://www.intel.com/pressroom/archive/speeches/gem93097.ht...
    • marcosdumay 9y ago
      That's because there was some sweet spot under that figure. Bigger, lower tech transistors lead to a more expensive chip because it was too big, and smaller higher tech transistors lead to bigger costs because few companies could make them. Unfortunately, that is all history. Current top of line fabrication processes cost more per area than their ancestors.
  • petra 9y ago
    If that's the case, why there's such strong r&d effort on die minimization ?
    • Nokinside 9y ago
      To increase number of transistors without compromising speed and reduce energy consumption. Nobody voluntarily transfers cost decreases to customers unless they have to.
• simonh 9y ago
  I suppose the money for the wages of all the people working at the billion dollar silicon chip fab plant has to come from somewhere.
• imtringued 9y ago
  Because it will cost you 10 million dollars+ to produce your first chip. Every chip after that costs you 7 cents.