Efinix Sapphire RV64 Brings 64-Bit RISC-V and Linux to Its FPGA Soft-Core Line
Efinix announced the Sapphire RV64 SoC on September 28, extending its FPGA-hosted Sapphire processor family from 32-bit designs to a configurable 64-bit RISC-V platform. The new soft SoC supports embedded Linux through an optional SV39 memory-management unit and is available across all Titanium and Topaz FPGAs plus Trion devices from the T20 upward.
The published Sapphire RV64 data sheet describes configurations with one to four 64-bit RISC-V processors, clock settings from 20 MHz to 400 MHz subject to the FPGA design's achievable fMAX, 4 KB to 512 KB of on-chip RAM, multi-way L1 instruction and data caches, and an optional 64 KB to 512 KB eight-way L2 cache. Efinix is positioning that expanded processor and memory subsystem for designs that need Linux, larger memory spaces and tight integration with FPGA acceleration.
Sapphire RV64 specifications
| Capability | Sapphire RV64 |
|---|---|
| CPU configuration | 1–4 64-bit RISC-V processors |
| Base ISA | RV64IM |
| Optional ISA features | A, F, D, C, Zba, Zbb, Zbs, Zicbom; the current data sheet also documents Zbc |
| Pipeline | 7 stages |
| Configurable clock | 20–400 MHz; actual fMAX depends on implementation |
| On-chip RAM | 4–512 KB |
| L1 cache | Separate instruction/data caches, configurable up to 8 ways |
| L2 cache | Optional, 64–512 KB, up to 8 ways |
| Linux support | Optional SV39 MMU |
| Other CPU options | FPU, branch predictor, hardware/software prefetchers, PMP, custom instructions |
| External memory | DDR, HyperRAM and LPDDR4x controller options |
| FPGA support | All Titanium, all Topaz, Trion T20 and above |
| Development flow | Efinity IP Manager, Efinity IDE and Efinity RISC-V Embedded Software IDE |
The release announcement lists DDR3, HyperRAM and LPDDR4x operation at up to 3,200 Mbps for memory configurations aimed at larger embedded and AI workloads. The exact memory interface available to a design depends on the selected FPGA and controller configuration.
Why a 64-bit soft SoC matters inside an FPGA
A soft processor implements the CPU in programmable FPGA fabric, giving designers control over processor configuration and a short path between software and custom FPGA logic. The trade-off is consumption of programmable-logic resources that can otherwise serve application-specific functions.
Sapphire RV64 carries Efinix's custom-instruction mechanism into the 64-bit family. Application-specific operations can therefore be implemented in FPGA logic and exposed to software through custom instructions. For edge-AI and signal-processing designs, this creates a route to offload selected kernels while keeping control software on the RISC-V CPUs.
The move to RV64 also expands the practical software and memory envelope. SV39 provides the virtual-memory architecture needed for 64-bit Linux configurations, while the larger cache hierarchy and external-memory options target applications that have exceeded the address-space and memory-system limits of smaller 32-bit embedded processors.
One to four CPUs, with implementation-dependent performance
The detailed data sheet adds an important capability beyond the launch summary: Sapphire RV64 can be configured with one to four processors. It also documents a 20–400 MHz configurable frequency range.
Those numbers describe the IP's configuration envelope. FPGA timing closure, enabled processor features, memory hierarchy, device family and the surrounding programmable logic determine the frequency and resource use of a deployed design. Efinix has not published a single cross-device performance benchmark that would turn the 400 MHz ceiling into a representative workload result.
For comparisons with hard RISC-V SoCs or Arm application processors, the exact target device and generated configuration therefore determine CPU throughput. Sapphire RV64's architectural advantage is configurability and close coupling to FPGA logic.
Availability and development path
Efinix says Sapphire RV64 is available for all Titanium and Topaz FPGAs and for Trion T20 devices and larger. Designers configure Sapphire cores through the Efinity IP Manager. Efinix's current support site lists Efinity 2026.1.132 and provides free software licenses and maintenance renewals.
Existing Sapphire users also retain a common development model across the RV32 and RV64 families. Efinix positions that continuity as a migration path for designs that need more addressable memory, deeper caches, richer I/O or 64-bit Linux while retaining the FPGA-centric architecture.
Deployment fit
Sapphire RV64 is most relevant to embedded systems where programmable logic is already central to the design: industrial control, machine vision, networking, signal processing and edge-AI systems that combine a general-purpose software stack with application-specific hardware pipelines.
For those systems, the release closes a meaningful capability gap in Efinix's soft-processor portfolio. Designers can keep the processor inside the FPGA fabric while moving to a 64-bit Linux-capable RISC-V architecture, scaling from a single CPU to a four-processor configuration and retaining custom-instruction acceleration.
Sources
- Efinix, Sapphire RV64 SoC Data Sheet v1.0: https://www.efinixinc.com/docs/riscv-sapphire-rv64-ds-v1.0.pdf
- Efinix, All Documentation / RISC-V SoCs: https://www.efinixinc.com/support/docs.php
- Efinix, Support Center / current Efinity software: https://www.efinixinc.com/support/
- Embedded Computing Design, Efinix Announces New Sapphire RV64 SoC (September 28, 2026): https://embeddedcomputing.com/technology/processing/chips-and-socs/efinix-announces-new-sapphire-rv64-soc-bringing-64-bit-risc-v-performance-to-embedded-fpga-designs
- Futurum, RISC-V Soft Cores Go 64-Bit With Efinix Sapphire RV64 (September 28, 2026): https://futurumgroup.com/insights/risc-v-soft-cores-go-64-bit-with-efinix-sapphire-rv64/