GeForce GTX 260 review - 2 - GTX series 200

GeForce GTX series 200

NVIDIA launched the GeForce GTX series 200, this launch includes both the GeForce GTX 260 and 280.

The new GTX series 200 GPUs are big man, they have roughly 1400 million transistors. It's the biggest chip that NVIDIA has ever built, with 1400M transistors it's a freak on a leash. Keep in mind that the GeForce 8800 'only' had roughly 700 Million processors. So that's roughly doubling up the previous transistor count. Interestingly enough, that would also double up the die-size of the processor and so you'd expect NVIDIA to move to a smaller fabrication process for this graphics processor. They did not as the new architecture is still based on a 65nm fabrication size. The chip is being made at TSMC and the biggest one they've ever made.

It resulted in a huge die measuring 24 x 24 mm. And not many chips will actually fit on a 300 mm wafer, since , resulting in a die area size of 576 mm2. We'll show you a photo I took of that die area later on, but I measured and it's indeed easily 5.5 cm. I have no clue how a chip this big really yields, but this certainly is one expensive graphics processor to make. We expect NVIDIA to move to a smaller fab process (55nm) pretty soon.

Let's walk through some of the main features (you need to stamp into your head) of this new beast:

• 1.4 billion transistors
• 993 GigaFLOP processing power
• 240 processing (shader) cores (GTX 280)
• 192 processing (shader) cores (GTX 260)
• DirectX 10
• New power management enhancements
• CUDA parallel processing
• GeForce PhysX

Obviously a big chunk of the transistors are being utilized for the shader cores. And shader cores the product surely has, 240 of them on the GeForce GTX 280. The new shader architecture has some cool new features. Sitting in-between them now is an integration of local cache memory (16k software managed cache). It is sitting in-between a block with 8 shader cores. So simply put, what helps here is that the data / instruction doesn't have to leave the GPU anymore to crunch it's data (normally in the regular frame buffer memory. This is a significant improvement in the architecture.

In the GPU, shaders are clustered in three blocks of eight shader processors. Then there are ten clusters totaling up towards the 240 shader units for the GeForce GTX 280. Now if you do the math with me real quick then the GeForce GTX 260 has to have 8 shader clusters with a total of 192 shader processors which you can utilize for gaming .. or computing other stuff.

Point of View GeForce GTX 260 crunching data in the test-system.