Cayman GPU tested once more
ComputerBase has posted a new entry in its “Test after 15 years” series, revisiting the Radeon HD 6950 1 GB and its original positioning against NVIDIA’s GeForce GTX 560 Ti. The site highlights how AMD introduced the 1,024 MB variant as a lower-cost option after the Radeon HD 6950 launched with 2,048 MB and then faced fresh competition in the same price segment.
The key change was VRAM capacity. ComputerBase notes the 1 GB model kept the same Cayman GPU, a 256-bit memory interface, and a 2,500 MHz effective GDDR5 memory clock, which it lists as 160,000 MB/s of bandwidth.
Radeon HD 6950 (2GB), Source: AMD
In the original 2011 test, ComputerBase listed the Radeon HD 6950 1,024 MB at €212, close to €20 below the 2 GB card, while GeForce GTX 560 Ti pricing started around €202 in the same period.
The Radeon HD 6950 1 GB generally delivered similar performance to the 2 GB model in typical settings and outpaced the GeForce GTX 560 Ti by about 5% to 18%, depending on resolution and quality. The 2 GB card’s advantage showed up more clearly at 2560 × 1600 with 4x anti-aliasing enabled, where the extra memory could matter.
Source: ComputerBase
ComputerBase notes that cutting the VRAM to 1 GB did not make the card run cooler or use less power. In its measurements, the 1 GB model actually pulled more power and ran hotter, and the site did not have a clear explanation beyond the possibility of a higher operating voltage.
| 2010/2011 Era GPUs | |||||
|---|---|---|---|---|---|
| Spec | Radeon HD 5870 | Radeon HD 6950 (1,024 MB) | Radeon HD 6970 | GeForce GTX 560 Ti | GeForce GTX 570 |
| Chip | Cypress | Cayman | GF114 | GF110 | |
| Transistors | Approx. 2.15 billion | Approx. 2.64 billion | Approx. 1.95 billion | Approx. 3.0 billion | |
| Process | 40 nm | ||||
| Core clock | 850 MHz | 800 MHz | 880 MHz | 822 MHz | 732 MHz |
| Shader clock | 850 MHz | 800 MHz | 880 MHz | 1,645 MHz | 1,464 MHz |
| Shader units (MAD) | 320 (5D) | 352 (4D) | 384 (4D) | 384 (1D) | 480 (1D) |
| FLOPS (MAD) | 2,720 GFLOPS | 2,253 GFLOPS | 2,703 GFLOPS | 1,253 GFLOPS | 1,405 GFLOPS |
| ROPs | 32 | 40 | |||
| Pixel fill rate | 27,200 MPix/s | 25,600 MPix/s | 28,160 MPix/s | 26,304 MPix/s | 21,960 MPix/s |
| TMUs | 80 | 88 | 96 | 64 | 60 |
| TAUs | 80 | 88 | 96 | 64 | 60 |
| Texel fill rate | 68,000 MTex/s | 70,400 MTex/s | 84,480 MTex/s | 52,608 MTex/s | 43,920 MTex/s |
| Shader model | SM 5 | ||||
| Windows power-saving | ✓ | ||||
| Memory capacity | 1,024 MB GDDR5 | 1,024 / 2,048 MB GDDR5 | 2,048 MB GDDR5 | 1,024 MB GDDR5 | 1,280 MB GDDR5 |
| Memory clock (effective) | 2,400 MHz | 2,500 MHz | 2,750 MHz | 2,004 MHz | 1,900 MHz |
| Memory bus | 256-bit | 320-bit | |||
| Memory bandwidth | 153,600 MB/s | 160,000 MB/s | 176,000 MB/s | 128,256 MB/s | 152,000 MB/s |
Source: ComputerBase
