The ATI Radeon HD 4830

The official ATI Radeon HD 4830 page and the press release.

This is a nice article from HardwareZone on the new ATI Radeon HD 4830 (RV770LE) GPU.

Read the full article: Plugging the Performance Gap...

... Before we embark on our benchmarking however, let us introduce this new Radeon HD 4830 GPU, codenamed RV770LE. First and foremost, if you guessed that it is a close derivative of the HD 4850 and HD 4870, you're right on the mark. In fact, it is really a stripped down HD 4850 with fewer stream processors and lower core and memory clock speeds....

Then the follow-up article, wherein techPowerUp (maker of GPU-Z), discovered the Stream Processor Mix-up - 560 vs. 640 SPs.

... Briefly, what happened was that while updating GPU-Z to include support for the new HD 4830, the good people at techPowerUp! noticed that some of the cards they have in hand had 560 stream processors instead of the advertised 640...

The respose from AMD:

.... AMD has identified that, in addition to reference samples of the ATI Radeon HD 4830 boards sent to media with a pre-production BIOS potentially impacting the card's performance, a very limited number of ATI Radeon HD 4830 boards were released to market with the same pre-production BIOS. This is in no way hardware related, and an updated BIOS fully resolves the performance limitation...

And lastly, the said 560 to 640 SP BIOS fix.