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Since most of us don't design CPUs or micros, does it matter much whether it's RISC-V vs ARM? In other words, is there any way to contribute in the RISC-V space

Since most of us don't design CPUs or micros, does it matter much whether it's RISC-V vs ARM? In other words, is there any way to contribute in the RISC-V space and gain an advantage? I can see how it could work out for Intel or Nvidia but for an end-user I can't see how I would jump away from the architecture I've spent the last 10 years on.

gary_0 4y ago
To the end user, it won't matter much either way, because most open source software already compiles and runs just fine on RISC-V; there are plans for projects like Chromium and Android to fully support RISC-V. RISC-V is on a trajectory to "just work". However, what does matter is that the RISC-V ISA will be cheaper and more flexible for device manufacturers to use. That's why it's superior to ARM and has already partly supplanted it for smaller chips (there are over 1 billion RISC-V chips in use already).
- brucehoult 4y ago
  10 billion as at the middle of last year. And Qualcomm alone had shipped 650 million of them.
  - gary_0 4y ago
    I had a feeling my number was out of date, but wow!
FullyFunctional 4y ago
I can see some reasons: * if you want to support the development of RISC-V as an alternative to x86 Arm /have some preference for not supporting x86 or Arm. * if you are writing code generators, you may find RISC-V easier to generate code for. If you don't care about these, then I would agree, keep using what works best for you.
brucehoult 4y ago
Technically they are close enough that you mostly don't care. Many RISC-V core customers say they ended up with using less silicon area / cost / energy usage at the same performance level. Arm proponents say their code size is a little smaller in 32 bit -- RISC-V is definitely significantly smaller code than Arm or x86 in 64 bit. But we're only talking 10% or 20% difference here. The big difference is Arm is owned by a single company that can and does change its contract terms and prices, sues its customers, obsoletes old stuff at will etc. RISC-V is managed by a non-profit that is steering along a path agreed by its hundreds of member companies, but can't and doesn't stop anyone from adding custom stuff as long as they stay compatible with the core ISA. There is a promise to only add capability over time, but keeping compatibility with the core 32 and 64 bit ISAs published in 2015 and ratified in 2019 ... forever. There are already a dozen or more companies competing to design the best and most competitive and compatible RISC-V cores and chips, and that's only going to increase. If the company you are using falls behind or raises prices or goes out of business then you can just switch to another -- as long as you didn't drink their proprietary extension cool-aid (it can be very tasty). The current limits of the RISC-V ecosystem are (I currently have one sitting in front of me, and ssh access to the other): - WCH CH32V003 microcontroller with 2 KB RAM and 16 KB flash in an 8 pin package for 10c each or 20 pin package for $14.6c https://www.aliexpress.us/item/3256804850399956.htm https://www.aliexpress.us/item/3256804850399956.htm - Sophon SG2042 64x 2.0 GHz OoO cores similar to Arm A72, each core with a 256 bit vector unit, 64K L1 cache, 1M L2 (shared per 4 cores), 4M L3 local to a cluster of 4 cores, with the other 15x 4 MB L3 accessible via NoC at ~half the local bandwidth. 32 lanes of PCIe gen 4. https://www.sophon.ai/product/introduce/sg2042.html https://www.sophon.ai/product/introduce/sg2042.html

gary_0 4y ago

To the end user, it won't matter much either way, because most open source software already compiles and runs just fine on RISC-V; there are plans for projects like Chromium and Android to fully support RISC-V. RISC-V is on a trajectory to "just work". However, what does matter is that the RISC-V ISA will be cheaper and more flexible for device manufacturers to use. That's why it's superior to ARM and has already partly supplanted it for smaller chips (there are over 1 billion RISC-V chips in use already).

brucehoult 4y ago
10 billion as at the middle of last year. And Qualcomm alone had shipped 650 million of them.
- gary_0 4y ago
  I had a feeling my number was out of date, but wow!

FullyFunctional 4y ago

I can see some reasons: * if you want to support the development of RISC-V as an alternative to x86 Arm /have some preference for not supporting x86 or Arm. * if you are writing code generators, you may find RISC-V easier to generate code for. If you don't care about these, then I would agree, keep using what works best for you.

brucehoult 4y ago

Technically they are close enough that you mostly don't care. Many RISC-V core customers say they ended up with using less silicon area / cost / energy usage at the same performance level. Arm proponents say their code size is a little smaller in 32 bit -- RISC-V is definitely significantly smaller code than Arm or x86 in 64 bit. But we're only talking 10% or 20% difference here. The big difference is Arm is owned by a single company that can and does change its contract terms and prices, sues its customers, obsoletes old stuff at will etc. RISC-V is managed by a non-profit that is steering along a path agreed by its hundreds of member companies, but can't and doesn't stop anyone from adding custom stuff as long as they stay compatible with the core ISA. There is a promise to only add capability over time, but keeping compatibility with the core 32 and 64 bit ISAs published in 2015 and ratified in 2019 ... forever. There are already a dozen or more companies competing to design the best and most competitive and compatible RISC-V cores and chips, and that's only going to increase. If the company you are using falls behind or raises prices or goes out of business then you can just switch to another -- as long as you didn't drink their proprietary extension cool-aid (it can be very tasty). The current limits of the RISC-V ecosystem are (I currently have one sitting in front of me, and ssh access to the other): - WCH CH32V003 microcontroller with 2 KB RAM and 16 KB flash in an 8 pin package for 10c each or 20 pin package for $14.6c https://www.aliexpress.us/item/3256804850399956.htm https://www.aliexpress.us/item/3256804850399956.htm - Sophon SG2042 64x 2.0 GHz OoO cores similar to Arm A72, each core with a 256 bit vector unit, 64K L1 cache, 1M L2 (shared per 4 cores), 4M L3 local to a cluster of 4 cores, with the other 15x 4 MB L3 accessible via NoC at ~half the local bandwidth. 32 lanes of PCIe gen 4. https://www.sophon.ai/product/introduce/sg2042.html https://www.sophon.ai/product/introduce/sg2042.html