A lot of ex-Alpha engineers went to PA-Semi which Apple then acquired.
Those people are responsible for the epic custom Apple ARM CPUs.
271 karma · joined August 28, 2013
x86 vs. ARM/RISC-V has fewer registers which can mean more spill/fill to the stack which results in more instructions to do the same work.
The instruction decode length for x86 has been creeping up with 64-bit encodings and SIMD extenstion (prefix bytes) as you can see it's 3.96 for x86 vs. 4.00 for ARM.
It’s hard to see how AMD would get capacity ahead of Intel CPUs.
I have no idea why they haven't done this already.
You need to be competitive on single thread performance to have a chance at datacenter. Amdahl's law is still very relevant. Up until very very recently, the CPUs were not up to par.
Bob's purpose vs. It's purpose
For consistency, shouldn't we use: Bobs purpose
The Atmel CPU is more constrained but still has hardware breakpoints, IO instructions, watchdog timers and interrupt support. It also has far more complex addressing modes (more CISC-y) to save on instruction counts and a variable length instruction set encoding where memory space to store code is a first order concern.
I’m also sure there is a memory controller to control the SRAM.
So, even if you were to build a simple micro controller, you’d need a lot more features and most likely higher performance (and power efficiency) than you would get from a trivial 2-stage pipeline. Not to mention there are no instruction or data caches in this RISC-V machine.
You couldn’t run anything but small toy programs on this machine. This is more like what a student would build in an undergraduate course in computer architecture.
For example, there is no MMU, no debug support, no traps, no interrupts, no exception handling, no OS privledge levels, no FP, no memory controller etc.
Of course, one wouldn’t implement all of these in a few hours.
The fact that this is RISCV is somewhat of a red herring as you could do a similar thing with a restricted subset of MIPS or ARM or even x86 as they do in UT Austin’s comp arch class.
https://www.designweek.co.uk/issues/26-february-4-march-2018...
The proof of the 4 color theorem "reduced the infinitude of possible maps to 1,936 reducible configurations (later reduced to 1,476) which had to be checked one by one by computer and took over a thousand hours."
Of course beauty is subjective and not well defined. Some might consider that proof beautiful.
Good luck with that. Power costs go up linearly at best with cores if you don't have any more transistor scaling.
That's a fin of a modern transistor (Intel 22nm). The dots in the photo are atoms. It's fair to say that Moore's law is nearing an end or has already ended.
It was only after I graduated and lived in the real world for a few years that I felt more 'well rounded'.
The tools to become a 'well informed citizen' should be taught at the high school level since not everyone goes to college.
The stock price reflects the market's overall expectation of all future cash flows discounted to the present value - all the way out to infinity.
When you buy at stock, you are implicitly betting that reality will exceed those expectations.
So, you just said that massive growth is priced in, and the fact you hold the stock implies that you are betting on even more massive growth - relative to expectations.
Twitter has a multitude of opportunities to monetize their user base. Their management has just done a poor job.