3 ms·

I don't completely agree that fabbing a chip is "prohibitively expensive and insanely work-intensive." While it's not cheap, lots of university projects fab chi

I don't completely agree that fabbing a chip is "prohibitively expensive and insanely work-intensive." While it's not cheap, lots of university projects fab chips using multi project wafer services. For example, the Rocket core from Berkeley has been taped out 11 times: https://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-17.html https://www.eecs.berkeley.edu/Pubs/TechRpts/2016/EECS-2016-1... and can boot Linux. But, I agree with your point that a simulator is a much easier step that gets most of the data.

kristianp 10y ago
Another example is the kilocore cpu in the news last month: https://www.ucdavis.edu/news/worlds-first-1000-processor-chip https://www.ucdavis.edu/news/worlds-first-1000-processor-chi...
cfallin 10y ago
Fair point -- I forgot about MOSIS. Agreed, pretty reasonable for small test runs. I guess I've mostly heard of tapeouts when proving out a full design though, e.g. TRIPS from UT-Austin (and they had a team of ~20 students, so that was worth a number of dissertations). I can't imagine doing a tapeout while working on caching or branch prediction or other core comparch subfields like that -- the deliverable is an algorithm and/or a new idea, not a physical proof of concept, and the usual effort (a grad-student-year or two, at most) isn't high enough. (All that said, seeing a real chip at the end of a project must be a heck of an exhilarating feeling of success...)
russdill 10y ago
Even companies worth billions that have their own fab simulate the chip first before fabbing it to test it and benchmark it.
- majewsky 10y ago
  Exactly. For a primary source, see this talk from 32C3 where an AMD CPU designer explained their process in detail: https://media.ccc.de/v/32c3-7171-when_hardware_must_just_work https://media.ccc.de/v/32c3-7171-when_hardware_must_just_wor...

3 ms·

I don't completely agree that fabbing a chip is "prohibitively expensive and insanely work-intensive." While it's not cheap, lots of university projects fab chi

by jeffbush 10y ago

kristianp 10y ago
Another example is the kilocore cpu in the news last month: https://www.ucdavis.edu/news/worlds-first-1000-processor-chip https://www.ucdavis.edu/news/worlds-first-1000-processor-chi...
cfallin 10y ago
Fair point -- I forgot about MOSIS. Agreed, pretty reasonable for small test runs. I guess I've mostly heard of tapeouts when proving out a full design though, e.g. TRIPS from UT-Austin (and they had a team of ~20 students, so that was worth a number of dissertations). I can't imagine doing a tapeout while working on caching or branch prediction or other core comparch subfields like that -- the deliverable is an algorithm and/or a new idea, not a physical proof of concept, and the usual effort (a grad-student-year or two, at most) isn't high enough. (All that said, seeing a real chip at the end of a project must be a heck of an exhilarating feeling of success...)
russdill 10y ago
Even companies worth billions that have their own fab simulate the chip first before fabbing it to test it and benchmark it.
- majewsky 10y ago
  Exactly. For a primary source, see this talk from 32C3 where an AMD CPU designer explained their process in detail: https://media.ccc.de/v/32c3-7171-when_hardware_must_just_work https://media.ccc.de/v/32c3-7171-when_hardware_must_just_wor...