Introduction

AMD's new 40-nm Radeon HD 4770 was a great success, maybe more successful than many people expected. Together with the limited availability due to yield problems at TSMC there were very few HD 4770 cards available on the market and those sold quickly. To counter this shortage, AMD has created the HD 4730 SKU. It is based on the RV770 which powers the HD 48xx Series, yet is heavily reduced in features. For example the number of shaders has been lowered to 640 (like on the HD 4830). The memory bus width has been cut down to 128-bit, but GDDR5 memory chips are used which effectively gives the card the same bandwidth as a 256 bit GDDR3 based HD 4830. Reducing the memory bus width to 128 bit has more implications. Due to the design of the memory controller the number of ROPs has been halved to 8 as well.
Please note the considerably higher core clock of the HD 4730 compared to other cards like the HD 4850 or even HD 4870.

Sapphire is one of two AIBs who are making the HD 4730 at this time, PowerColor is the second. As I am told by Sapphire the "HD 4730 GPU chips have to be ordered specifically at AMD". This means that AIBs are not just using their excess HD 4830 GPUs on these boards. It could still mean that AMD ships their excess HD 4830 GPUs as HD 4730 GPUs to AIBs. Whether any different binning is used is not known.

When the card was first announced Sapphire told us that there won't be any review samples, so I went out and bought a retail card here in Germany which has surprisingly good stock of the Sapphire HD 4730.