AMD Radeon HD 7850M vs AMD Radeon HD 8870 OEM
Graphics Processor
| GPU model | Heathrow | Pitcairn |
|---|---|---|
| GPU variant | Heathrow PRO | Pitcairn XT (215-0828047) |
| Architecture | GCN 1.0 | GCN 1.0 |
| Foundry | TSMC | TSMC |
| Manufacturing process | 28 nm | 28 nm |
| Number of transistors | 1,500 million | 2,800 million |
| Die size | 123 mm² | 212 mm² |
Mobile graphics
| Release date | Apr 24th, 2012 | — |
|---|---|---|
| Generation | London (HD 7800M) | — |
| Production | End-of-life | — |
| Interface | PCIe 3.0 x16 | — |
| Predecessor | Vancouver | — |
| Successor | Solar System | — |
Clocks
| GPU clock | 675 MHz | 1000 MHz |
|---|---|---|
| Memory clock | 1000 MHz 4 Gbps effective | 1200 MHz 4.8 Gbps effective |
Memory Configuration
| Memory size | 2 GB | 2 GB |
|---|---|---|
| Memory type | GDDR5 | GDDR5 |
| Memory bus width | 128 bit | 256 bit |
| Bandwidth | 64.00 GB/s | 153.6 GB/s |
Render Configuration
| Shading units | 640 | 1280 |
|---|---|---|
| TMUs | 40 | 80 |
| ROPs | 16 | 32 |
| Compute units | 10 | 20 |
| Cache L1 | 16 KB (per CU) | 16 KB (per CU) |
| Cache L2 | 256 KB | 512 KB |
Performance
| Pixel rate | 10.80 GPixel/s | 32.00 GPixel/s |
|---|---|---|
| Texture rate | 27.00 GTexel/s | 80.00 GTexel/s |
| FP32 (float) performance | 864.0 GFLOPS | 2.560 TFLOPS |
| FP64 (double) performance | 54.00 GFLOPS (1:16) | 160.0 GFLOPS (1:16) |
Dimensions & Outputs
| TDP | 40 W | 175 W |
|---|---|---|
| Outputs | No outputs | 1x DVI1x HDMI2x mini-DisplayPort |
| Slot width | — | Dual-slot |
| Length | — | 241 mm 9.5 inches |
| Suggested PSU | — | 450 W |
| Power connectors | — | 2x 6-pin |
| Board number | — | C401 |
API Support & Features
| DirectX | 12 (11_1) | 12 (11_1) |
|---|---|---|
| OpenGL | 4.6 | 4.6 |
| OpenCL | 1.2 | 1.2 |
| Vulkan | 1.2 | 1.2 |
| Shader model | 5.1 | 5.1 |
Other Features
Graphics Card
| Release date | — | Jan 8th, 2013 |
|---|---|---|
| Generation | — | Sea Islands |
| Production | — | End-of-life |
| Interface | — | PCIe 3.0 x16 |
| Predecessor | — | Southern Islands |
| Successor | — | Volcanic Islands |
