The "smallest GPU" has received a major update. Amateur FPGA designer and retro PC enthusiast Pongsagon Vichit has just released TinyGPU v2.0. This GPU is described as a standalone processor capable of rasterization, transformation, and lighting processing (similar to the GeForce 256).
Vichit (aka @MattDIYgraphics on Xbox) also stated that this GPU has been submitted for the upcoming Tiny Tapeout testing, and it will be packaged with approximately 200,000 transistors within the maximum allowed 4x4 tile size. In comparison, the market-leading Nvidia RTX 5090 boasts 92.2 billion transistors, but due to its significantly higher transistor count, its performance naturally increases exponentially.
Performance of 25MHz
In terms of performance, the 25 MHz v2.0 version only achieves a frame rate of 7.5 to 15 fps. Furthermore, this only applies to low-poly 3D models, rendering at a resolution of 320 x 240 pixels (or lower), and using 4-bit color (up to 16 colors displayed simultaneously). The designers state that the Tiny Tapeout chip won't run faster than the demo program based on the Basys3 FPGA. Therefore, TinyGPU v2.0 certainly won't be on our list of best gaming GPUs.
While this resolution and color depth of graphics may be closer to early 1980s home computers, it utilizes some more advanced technologies. Specifically, Vichit explains that TinyGPU v2.0 performs interactive 3D vector-to-raster conversion, and it uses GPU transformation and lighting technology, first introduced to the consumer market in October 1999 with Nvidia's landmark GeForce 256 graphics card.
Other technical highlights of TinyGPU v2.0 include "4-bit double buffering, 8-bit depth buffer storage on QSPI RAM, up to 1K triangles, backface culling, one dynamic directional light [and] planar shading".
TinyGPU v2.0 has been submitted to Tiny Tapeout for the next round of production. Its maximum allowed 16-tile design will bring the cost of Vichit to approximately $1500. You can learn more, delve into the Verilog source code, and browse other resources through the GitHub repository linked at the top.
Report about Tiny GPU
Back in April 2024, we reported on another Tiny GPU, designed "from scratch" by Adam Majmudar with no prior experience. It was ready for its chip debut with the Tiny Tapeout 7 (TT7).
However, Vichit also entered his device, dubbed the "smallest GPU," into the TT7 competition. It's interesting to compare this hobbyist's initial and latest "smallest GPU" projects, as they are quite different. The first-generation product was extremely streamlined, supporting a maximum of only two polygons (far fewer than the second generation's 1000). Due to its simplicity, this 50MHz "smallest GPU" could render 640 x 480 pixel, 6-bit color depth images in real-time at up to 60fps. On-screen rendering output was controlled via a keyboard cursor.
It was described as:
This is the smallest ASIC GPU. It can use two triangles for texture mapping to render quadrilaterals.
This design uses approximately 16,000 gates/cells and approximately 200 bytes of triggers for all the memory required for the graphics pipeline. This achieves a maximum capacity of 16 tiles on the tinytapeout chip.
The chip comes with two texture ROM images. (My school's logo)
Transformation, lighting, and rasterization are all performed in the GPU.
It supports solid shading and affine texture mapping for unidirectional light sources.
Each frame, all 3D data (vertices, transforms, rendering modes) is sent to the ASIC.
The output signal is sent to a VGA monitor via TinyVGA. The output resolution is 640x480 pixels, 6-bit RGB color mode, and the frame rate is 60 fps.
The clock frequency is 50 MHz.
Source: Content compiled from tomshardware
