AMD Radeon HD 7850M vs ATI Radeon HD 4870
Graphics Processor
| GPU model | Heathrow | RV770 |
|---|---|---|
| GPU variant | Heathrow PRO | RV770 XT (215-0669049) |
| Architecture | GCN 1.0 | TeraScale |
| Foundry | TSMC | TSMC |
| Manufacturing process | 28 nm | 55 nm |
| Number of transistors | 1,500 million | 956 million |
| Die size | 123 mm² | 256 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 | 750 MHz |
|---|---|---|
| Memory clock | 1000 MHz 4 Gbps effective | 900 MHz 3.6 Gbps effective |
Memory Configuration
| Memory size | 2 GB | 512 MB |
|---|---|---|
| Memory type | GDDR5 | GDDR5 |
| Memory bus width | 128 bit | 256 bit |
| Bandwidth | 64.00 GB/s | 115.2 GB/s |
Render Configuration
| Shading units | 640 | 800 |
|---|---|---|
| TMUs | 40 | 40 |
| ROPs | 16 | 16 |
| Compute units | 10 | 10 |
| Cache L1 | 16 KB (per CU) | 16 KB (per CU) |
| Cache L2 | 256 KB | 256 KB |
Performance
| Pixel rate | 10.80 GPixel/s | 12.00 GPixel/s |
|---|---|---|
| Texture rate | 27.00 GTexel/s | 30.00 GTexel/s |
| FP32 (float) performance | 864.0 GFLOPS | 1,200 GFLOPS |
| FP64 (double) performance | 54.00 GFLOPS (1:16) | 240.0 GFLOPS (1:5) |
Dimensions & Outputs
| TDP | 40 W | 150 W |
|---|---|---|
| Outputs | No outputs | 2x DVI1x S-Video |
| Slot width | — | Dual-slot |
| Length | — | 241 mm 9.5 inches |
| Width | — | 111 mm 4.4 inches |
| Height | — | 40 mm 1.6 inches |
| Suggested PSU | — | 450 W |
| Power connectors | — | 2x 6-pin |
| Board number | — | B507-31 |
API Support & Features
| DirectX | 12 (11_1) | 10.1 (10_1) |
|---|---|---|
| OpenGL | 4.6 | 3.3 |
| OpenCL | 1.2 | 1.1 |
| Vulkan | 1.2 | — |
| Shader model | 5.1 | 4.1 |
Other Features
Graphics Card
| Release date | — | Jun 25th, 2008 |
|---|---|---|
| Generation | — | Radeon R700 |
| Production | — | End-of-life |
| Launch price | — | 299 USD |
| Interface | — | PCIe 2.0 x16 |
| Reviews | — | 135 in our database |
| Predecessor | — | Radeon R600 |
| Successor | — | Evergreen |
