# Vortex: Extending the RISC-V ISA for GPGPU and 3D-GraphicsResearch

arXiv: https://arxiv.org/abs/2110.10857 · HTML: https://mlsanity.com/paper/2110.10857/

## Key facts

- Cited by 4 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 21 Oct 2021.

## Built on by (most cited first, 4 of 4)

- [HighTide: An Agent-Curated Open-Source VLSI Benchmark Suite](https://mlsanity.com/paper/2606.04126/) (2026)
- [Failure Tolerant Training with Persistent Memory Disaggregation over CXL](https://mlsanity.com/paper/2301.07492/) (2023)
- [Accelerating HDC-CNN Hybrid Models Using Custom Instructions on RISC-V GPUs](https://mlsanity.com/paper/2511.05053/) (2025)
- [Hardware Mechanisms to Dynamically Throttle AI Performance](https://mlsanity.com/paper/2607.18069/) (2026)

## Abstract (arXiv)

The importance of open-source hardware and software has been increasing. However, despite GPUs being one of the more popular accelerators across various applications, there is very little open-source GPU infrastructure in the public domain. We argue that one of the reasons for the lack of open-source infrastructure for GPUs is rooted in the complexity of their ISA and software stacks.In this work, we first propose an ISA extension to RISC-V that supports GPGPUs and graphics. The main goal of the ISA extension proposal is to minimize the ISA changes so that the corresponding changes to the open-source ecosystem are also minimal, which makes for a sustainable development ecosystem. To demonstrate the feasibility of the minimally extended RISC-V ISA, we implemented the complete software and hardware stacks of Vortex on FPGA. Vortex is a PCIe-based soft GPU that supports OpenCL and OpenGL.Vortex can be used in a variety of applications, including machine learning, graph analytics, and graphics rendering. Vortex can scale up to 32 cores on an Altera Stratix 10 FPGA, delivering a peak performance of 25.6 GFlops at 200 Mhz.