Graphics Processor Details
Nvidia’s GeForce GTX 480M is based on the same Fermi architecture as its high-flying GeForce GTX 480 desktop card, so that our previous analysis allows us to focus on the things that make this mobile version different from its desktop counterpart.
| Desktop vs. Mobile GeForce Graphics | |||
|---|---|---|---|
| Row 0 - Cell 0 | Desktop GeForce GTX 480 | Desktop GeForce GTX 465 | GeForce GTX 480M |
| Transistors | 3 billion | 3 billion | 3 billion |
| Engine Clock | 700 MHz | 607 MHz | 425 MHz |
| Stream Processors | 480 | 352 | 352 |
| Texture Units | 60 | 44 | 44 |
| ROP Units | 40 | 32 | 32 |
| Compute Performance | 1345 GFLOPS | 855 GFLOPS | 598 GFLOPS |
| DRAM Type | GDDR5-3696 | GDDR5-3206 | GDDR5-2400 |
| DRAM Interface | 384-bits | 256-bits | 256-bits |
| Memory Bandwidth | 177.4 GB/s | 102.6 GB/s | 76.8 GB/s |
| TDP | 250 W | 200 W | 100 W |
Whoops! It appears that the GeForce GTX 480M is equivalent to a power-optimized, underclocked GeForce GTX 465 with 2 GB of slower RAM! And yet, Nvidia isn’t the only company doing this with its notebook parts, as the chart from our previous Mobility Radeon HD 5870 test clearly proves.
| Desktop vs. Mobility Radeon Graphics | |||
|---|---|---|---|
| Row 0 - Cell 0 | Desktop Radeon HD 5870 | Desktop Radeon HD 5770 | Mobility Radeon HD 5870 |
| Transistors | 2.15 billion | 1.04 billion | 1.04 billion |
| Engine Clock | 850 MHz | 850 MHz | 700 MHz |
| Shader (ALUs) | 1600 | 800 | 800 |
| Texture Units | 80 | 40 | 40 |
| Z/Stencil Units | 128 | 64 | 64 |
| Compute Performance | 2.72 TFLOPS | 1.36 TFLOPS | 1.12 TFLOPS |
| DRAM Type | GDDR5-4800 | GDDR5-4800 | GDDR5-4000 |
| DRAM Interface | 256-bits | 128-bits | 128-bits |
| Memory Bandwidth | 153.6 GB/s | 76.8 GB/s | 64.0 GB/s |
| TDP | 188 W | 108 W | 50 W |
The GeForce GTX 480M is a low-power version of the GeForce GTX 465, just as the Mobility HD 5870 is a low-power version of the Radeon HD 5770. Nvidia’s relabeling of a mid-priced desktop component as a high-end mobile part is thus a perfect match to what its competitor is doing, and light-years ahead of its previous naming scheme.
If you're here reading this story, you'll know exactly what to expect from the mobile flagships from AMD and Nvidia. It's the folks who don't do their homework before buying we're most worried about. Calling these modules GeForce GTX 480 and Radeon HD 5870 simply sends the wrong message. With that said, we've agreed to disagree with both companies' marketing departments. They think they're simply suggesting each card is best-in-class, as on the desktop. We think they're establishing certain performance expectations that'll fall far short of the desktop.
Moving forward, we'll put aside AMD's higher computational performance numbers and power savings from the above charts, since these two completely-different architectures are rated using dissimilar methodology by their manufacturers. Instead, we'll rely on benchmark data and power measurements. The proof in the pudding is, after all, in the eating.
