Comment by camel-cdr
20 days ago
The SpacemiT K3 with 8 SpacemiT X100 RVA23 cores, which are faster than Pi4 but slower than Pi5, should be available in a couple of months:
geekbench: https://browser.geekbench.com/v6/cpu/16145076
rvv-bench: https://camel-cdr.github.io/rvv-bench-results/spacemit_x100/...
There are also 8 additional SpacemiT-A100 cores with 1024-bit wide vectors, which are more like an additional accelerator for number crunshing.
The Milk-V Titan has slightly faster scalar performance, than the K3.
> faster than Pi4 but slower than Pi5
It may actually be faster than a Pi5.
The benchmark is well tuned for ARM64 but not so well adapted to RISC-V, especially the vector extensions.
You may still be right of course. The SpaceMIT K3 is exciting because it may still be the first RVA23 hardware but it is not exectly going to launch a RISC-V laptop industry.
There isn't much to tune in some, e.g. the clang benchmark. We know that many of the benchmarks already have RVV support (compare BPI-F3 results between versions) and three are still missing RVV support. I think the optimized score would be in the 500s, but that's still a lot lower than Pi5.
> The Milk-V Titan has slightly faster scalar performance, than the K3.
So the main difference between this Milk-V Titan and the upcoming SpacemiT K3 is that the latter has better vector performance?
The Titan has no SIMD/Vector support at all, so it doesn't support RVA23.
The K3 is able to run RVA23 code, the Titan is not; it lacks V.
It matters, as the ecosystem settled on RVA23 as the baseline for application processors.
Well, today it is only Ubuntu 25.10 and newer that require RVA23. Almost everything else will run on plain old RV64GC which this board handles no problem.
But you are correct that once RVA23 chips begin to appear, everybody will move to it quite quickly.
RVA23 provides essentially the same feature-set as ARM64 or x86-64v4 including both virtualization and vector capabilities. In other words, RVA23 is the first RISC-V profile to match what modern applications and workflows require.
The good news is that I expect this to remain the minimum profile for quite a long time. Even once RVA30 and future profiles appear, there may not be much pressure for things like Linux distributions to drop support for RVA23. This is a lot like the modern x86-64 space where almost all Linux distributions work just fine on x86-64 v1 even though there are now v2, v3, and v4 available as well. You can run the latest edition of Arch Linux on hardware from 2005. It is hard to predict the future but it would not surprise me if Ubuntu 30.04 LTS ran just fine on RISC-V hardware released later this year.
But ya, anything before RVA23, like the RVA22 Titan we are discussing here, will be stuck forever on older distros or custom builds (like Ubuntu 25.04).