AMD Radeon HD 6850 X2 vs NVIDIA GeForce GTX 660M Mac Edition
Graphics Processor
| GPU model | Barts | GK107 |
|---|---|---|
| GPU variant | Barts PRO (215-0798006) | — |
| Architecture | TeraScale 2 | Kepler |
| Foundry | TSMC | TSMC |
| Manufacturing process | 40 nm | 28 nm |
| Number of transistors | 1,700 million | 1,270 million |
| Die size | 255 mm² | 118 mm² |
Graphics Card
| Release date | Sep 19th, 2011 | — |
|---|---|---|
| Generation | Northern Islands | — |
| Production | End-of-life | — |
| Interface | PCIe 2.0 x16 | — |
| Reviews | 105 in our database | — |
| Predecessor | Evergreen | — |
| Successor | Southern Islands | — |
Clocks
| GPU clock | 800 MHz | 950 MHz |
|---|---|---|
| Memory clock | 1050 MHz 4.2 Gbps effective | 1250 MHz 5 Gbps effective |
Memory Configuration
| Memory size | 2 GB | 512 MB |
|---|---|---|
| Memory type | GDDR5 | GDDR5 |
| Memory bus width | 256 bit | 128 bit |
| Bandwidth | 134.4 GB/s | 80.00 GB/s |
Render Configuration
| Shading units | 960 | 384 |
|---|---|---|
| TMUs | 48 | 32 |
| ROPs | 32 | 16 |
| Compute units | 12 | — |
| Cache L1 | 8 KB (per CU) | 16 KB (per SMX) |
| Cache L2 | 512 KB | 256 KB |
| SMX count | — | 2 |
Performance
| Pixel rate | 25.60 GPixel/s | 7.600 GPixel/s |
|---|---|---|
| Texture rate | 38.40 GTexel/s | 30.40 GTexel/s |
| FP32 (float) performance | 1.536 TFLOPS | 729.6 GFLOPS |
| FP64 (double) performance | — | 30.40 GFLOPS (1:24) |
Dimensions & Outputs
| Slot width | Dual-slot | MXM Module |
|---|---|---|
| TDP | 254 W | 50 W |
| Suggested PSU | 600 W | — |
| Outputs | 2x DVI1x HDMI1x DisplayPort | No outputs |
| Power connectors | 2x 8-pin | None |
API Support & Features
| DirectX | 11.2 (11_0) | 12 (11_0) |
|---|---|---|
| OpenGL | 4.4 | 4.6 |
| OpenCL | 1.2 | 3.0 |
| Vulkan | — | 1.1 |
| Shader model | 5.0 | 5.1 |
| CUDA | — | 3.0 |
Other Features
Mobile graphics
| Release date | — | Apr 1st, 2013 |
|---|---|---|
| Generation | — | GeForce 600M |
| Production | — | End-of-life |
| Interface | — | MXM-B (3.0) |
| Predecessor | — | GeForce 500M |
| Successor | — | GeForce 700M |
