# ISA Comparison Table
-| Name | Num <br />opcodes | Class | Predicate <br /> Masks | Twin <br /> Predication | Explicit <br /> Vector regs | 128-bit | Bigint <br /> capability | LDST <br /> Fault-First | Data-dependent <br /> Fail-first | Predicate-<br /> Result |
-|------|-------------------|---------------|------------------------|-------------------------|------------------------------|---------|--------------------------|-------------------------|----------------------------------|-------------------------|
-| SVP64| 5{1} | Scalable{2} | yes | yes{3} | no{4} | n/a{5} | yes{6} | yes{7} | yes{8} | yes{9} |
-| VSX | 700+ | PackedSIMD | no | no | yes{10} | yes | no | no | no | no |
-| NEON | ~250{11} | PredicatedSIMD| yes | no | yes | yes | no | no | no | no |
-| SVE2 | ~1000{12} | HSCalable{13} | yes | no | yes | yes | no | no | no | no |
+| Name | Num <br />opcodes | Class | Predicate <br /> Masks | Twin <br /> Predication | Explicit <br /> Vector regs | 128-bit | Bigint <br /> capability | LDST <br /> Fault-First | Data-dependent <br /> Fail-first | Predicate-<br /> Result |
+|-------------|-------------------|---------------|------------------------|-------------------------|------------------------------|---------|--------------------------|-------------------------|----------------------------------|-------------------------|
+| SVP64 | 5{1} | Scalable{2} | yes | yes{3} | no{4} | n/a{5} | yes{6} | yes{7} | yes{8} | yes{9} |
+| VSX | 700+ | PackedSIMD | no | no | yes{10} | yes | no | no | no | no |
+| NEON | ~250{11} | PredicatedSIMD| yes | no | yes | yes | no | no | no | no |
+| SVE2 | ~1000{12} | HSCalable{13} | yes | no | yes | yes | no | yes{7} | no | no |
+| AVX-512{14} | ~1000s{15} | PredicatedSIMD| yes | no | yes | yes | no | no | no | no |
+| RVV{16} | ~190 | Scalable{17} | yes | no | yes | yes{18} | no | yes | no | no |
* {1}: plus EXT001 24-bit prefixing. See [[sv/svp64]]
* {2}: A 2-Dimensional Scalable Vector ISA with both Horizontal-First and Vertical-First Modes. See [[sv/vector_isa_comparison]]
* {12} difficult to exactly ascertain, see ARM Architecture Reference Manual Supplement, DDI 0584. Critically depends on ARM Scalar instructions.
* {13}: ARM states that the Scalability is a [Silicon-partner choice](https://developer.arm.com/-/media/Arm%20Developer%20Community/PDF/102340_0001_00_en_introduction-to-sve2.pdf?revision=aae96dd2-5334-4ad3-9a47-393086a20fea).
this "Scalability independence" is not entirely extended in full to the programmer although ARM requests developers to consider it so, in practice this does not happen.
+* {14}: [Wikipedia](https://en.wikipedia.org/wiki/AVX-512), [Lifecycle of an instruction set](https://media.handmade-seattle.com/tom-forsyth/) including full slides
+* {15}: difficult to exactly ascertain, contains subsets. Critically depends on ISA support from earlier x86 ISA subsets (several more thousand instructions). See [SIMD ISA listing](https://www.officedaytime.com/simd512e/)
+* {16}: [RVV Spec](https://github.com/riscv/riscv-v-spec/blob/master/v-spec.adoc)
+* {17}: Like the original Cray RVV is a truly scalable Vector ISA (Cray setvl instruction).
+* {18}: like SVP64 it is up to the hardware implementor to choose whether to support 128-bit elements.