# Kelvin (microarchitecture)

Kelvin is the codename for a GPU microarchitecture developed by Nvidia, and released in 2001, as the successor to the Celsius microarchitecture. It was named with reference to William Thomson (1st Baron Kelvin) and used with the GeForce 3 and 4 series.

## Graphics features

* DirectX 8.0 (8.1 in the original Xbox)
* OpenGL 1.2 (1.5; 1.4 in the original Xbox)
* Shader Model 1.3
* Vertex Shader 1.1
* Max VRAM size bumped to 128MB
* New memory controller with Z compression

## Chips
### GeForce 3 (3xxx) series

* NV20, 57 million transistor
* NV2A (Xbox GPU), 57 million transistor

### GeForce 4 (4xxx) series

* Crush11, 20 million transistor
* NV17, 29 million transistor
* NV18, 29 million transistor
* NV25, 63 million transistor
* NV28, 36 million transistor
* NV2A (Xbox GPU), 57 million transistor

## GPU list
### GeForce 3 (3xxx) series

| Model | Launch | Code name | Fab (nm) | Bus interface | Core clock (MHz) | Memory clock (MHz) | Core config$^1$ | Fillrate | Fillrate | Fillrate | Fillrate | Memory | Memory | Memory | Memory |
| Model | Launch | Code name | Fab (nm) | Bus interface | Core clock (MHz) | Memory clock (MHz) | Core config$^1$ | MOperations/s | MPixels/s | MTexels/s | MVertices/s | Size (MB) | Bandwidth (GB/s) | Bus type | Bus width (bit) |
| GeForce3 Ti200 | 1 October 2001 | NV20 | TSMC 150 nm | AGP 4× PCI | 175 | 200 | 4:1:8:4 | 700 | 700 | 1400 | 42.75 | 64 128 | 6.4 | DDR | 128 |
| GeForce3 | 27 February 2001 | NV20 | TSMC 150 nm | AGP 4× PCI | 200 | 230 | 4:1:8:4 | 800 | 800 | 1600 | 50 | 64 | 7.36 | DDR | 128 |
| GeForce3 Ti500 | 1 October 2001 | NV20 | TSMC 150 nm | AGP 4× PCI | 240 | 250 | 4:1:8:4 | 960 | 960 | 1920 | 60 | 64 128 | 8 | DDR | 128 |

### GeForce 4 (4xxx) series

| Model | Launch | Code name | Fab (nm) | Bus interface | Core clock (MHz) | Memory clock (MHz) | Core config$^1$ | Fillrate | Fillrate | Fillrate | Fillrate | Memory | Memory | Memory | Memory | Supported API version | Supported API version |
| Model | Launch | Code name | Fab (nm) | Bus interface | Core clock (MHz) | Memory clock (MHz) | Core config$^1$ | MOperations/s | MPixels/s | MTexels/s | MVertices/s | Size (MB) | Bandwidth (GB/s) | Bus type | Bus width (bit) | Direct3D | OpenGL |
| GeForce4 MX IGP + nForce2 | 1 October 2002 | NV1F | TSMC 150 nm | FSB | 250 | 133 200 | 2:0:4:2 | 500 | 500 | 1000 | 0 | Up to 128 system RAM | 2.128 6.4 | DDR | 64 128 | 7.0 | 1.2 |
| GeForce4 MX420 | 6 February 2002 | NV17 | TSMC 150 nm | AGP 4× PCI | 250 | 166 | 2:0:4:2 | 500 | 500 | 1000 | 0 | 64 | 2.656 | SDR DDR | 128 (SDR) 64 (DDR) | 7.0 | 1.2 |
| GeForce4 MX440 SE | 2002 | NV17 | TSMC 150 nm | AGP 4× PCI | 250 | 166 | 2:0:4:2 | 500 | 500 | 1000 | 0 | 64 128 | 5.312 | DDR | 128 | 7.0 | 1.2 |
| GeForce MX4000 | 14 December 2003 | NV18B | TSMC 150 nm | AGP 8× PCI | 250 | 166 | 2:0:4:2 | 500 | 500 | 1000 | 0 | 64 128 | 2.656 | DDR | 64 | 7.0 | 1.2 |
| GeForce PCX4300 | 19 February 2004 | NV18B | TSMC 150 nm | PCIe ×16 | 250 | 166 | 2:0:4:2 | 500 | 500 | 1000 | 0 | 128 | 2.656 | DDR | 64 | 7.0 | 1.2 |
| GeForce4 MX440 | 6 February 2002 | NV17 | TSMC 150 nm | AGP 4× PCI | 275 | 200 | 2:0:4:2 | 550 | 550 | 1100 | 0 | 64 128 | 6.4 | DDR | 128 | 7.0 | 1.2 |
| GeForce4 MX440 8x | 25 September 2002 | NV18 | TSMC 150 nm | AGP 8× PCI | 275 | 250 | 2:0:4:2 | 550 | 550 | 1100 | 0 | 64 128 | 8 | DDR | 128 | 7.0 | 1.2 |
| GeForce4 MX460 | 6 February 2002 | NV17 | TSMC 150 nm | AGP 4× PCI | 300 | 275 | 2:0:4:2 | 600 | 600 | 1200 | 0 | 64 128 | 8 | DDR | 128 | 7.0 | 1.2 |
| GeForce4 Ti4200 | 16 April 2002 | NV25 | TSMC 150 nm | AGP 4× | 250 | 222 (128 MB) 250 (64 MB) | 4:2:8:4 | 1000 | 1000 | 2000 | 125 | 64 128 | 7.104 (128 MB) 8 (64 MB) | DDR | 128 | 8.0a | 1.3 |
| GeForce4 Ti4200 8x | 25 September 2002 | NV28 | TSMC 150 nm | AGP 8× | 250 | 250 | 4:2:8:4 | 1000 | 1000 | 2000 | 125 | 128 | 8 | DDR | 128 | 8.0a | 1.3 |
| GeForce4 Ti4400 | 6 February 2002 | NV25 | TSMC 150 nm | AGP 4× | 275 | 275 | 4:2:8:4 | 1100 | 1100 | 2200 | 137.5 | 128 | 8.8 | DDR | 128 | 8.0a | 1.3 |
| GeForce4 Ti4400 8x (Ti4800SE$^2$) | 20 January 2003 | NV28 | TSMC 150 nm | AGP 8× | 275 | 275 | 4:2:8:4 | 1100 | 1100 | 2200 | 137.5 | 128 | 8.8 | DDR | 128 | 8.0a | 1.3 |
| GeForce4 Ti4600 | 6 February 2002 | NV25 | TSMC 150 nm | AGP 4× | 300 | 325 | 4:2:8:4 | 1200 | 1200 | 2400 | 150 | 128 | 10.4 | DDR | 128 | 8.0a | 1.3 |
| GeForce4 Ti4600 8x (Ti4800$^3$) | 20 January 2003 | NV28 | TSMC 150 nm | AGP 8× | 300 | 325 | 4:2:8:4 | 1200 | 1200 | 2400 | 150 | 128 | 10.4 | DDR | 128 | 8.0a | 1.3 |
| Model | Launch | Code name | Fab (nm) | Bus interface | Core clock (MHz) | Memory clock (MHz) | Core config$^1$ | Fillrate | Fillrate | Fillrate | Fillrate | Memory | Memory | Memory | Memory | Supported API version | Supported API version |
| Model | Launch | Code name | Fab (nm) | Bus interface | Core clock (MHz) | Memory clock (MHz) | Core config$^1$ | MOperations/s | MPixels/s | MTexels/s | MVertices/s | Size (MB) | Bandwidth (GB/s) | Bus type | Bus width (bit) | Direct3D | OpenGL |
| Model | Features | Features |
| Model | nFiniteFX II Engine | Video Processing Engine (VPE) |
| GeForce4 MX420 | No | Yes |
| GeForce4 MX440 SE | No | Yes |
| GeForce4 MX4000 | No | Yes |
| GeForce4 PCX4300 | No | Yes |
| GeForce4 MX440 | No | Yes |
| GeForce4 MX440 8X | No | Yes |
| GeForce4 MX460 | No | Yes |
| GeForce4 Ti4200 | Yes | No |
| GeForce4 Ti4200 8x | Yes | No |
| GeForce4 Ti4400 | Yes | No |
| GeForce4 Ti4400 8x | Yes | No |
| GeForce4 Ti4600 | Yes | No |
| GeForce4 Ti4600 8x | Yes | No |

### Console GPUs

| Model | Launch | Code name | Fab (nm) | Bus interface | Core clock (MHz) | Memory clock (MHz) | Core config$^{1,2,3}$ | Fillrate | Fillrate | Fillrate | Fillrate | Memory | Memory | Memory | Memory | Latest supported API version | Latest supported API version | Latest supported API version | Latest supported API version |
| Model | Launch | Code name | Fab (nm) | Bus interface | Core clock (MHz) | Memory clock (MHz) | Core config$^{1,2,3}$ | MOperations/s | MTexels/s | MPixels/s | MTri/s | Size (MB) | Bandwidth (GB/s) | Bus type | Bus width (bit) | Direct3D | OpenGL |
| XGPU (Xbox) | November 15, 2001 | NV2A | TSMC 150 nm | Integrated | 233 | 200 | 4:2:8:4$^1$ | 5,800 | 1,864 | 932 | 116.5 | 64 | 6.4 | DDR | 128 | 8.1 | 1.4 |