Awesam:
Is this better than a HIS 4670 512MB GDDR3?
Better? Faster yes, however uses lots of power, gets quite hot and is not the quietest of cards.
matto:
I wouldn't recommend the HD4730. It was designed as a stop gap when there weren't enough 40nm chips around to satisfy demand for the 4770. The 4730 is based on the older 60/55nm chips. This is more akin to a 4830 but runs at with a high clockrate. The high clock leads to heating/cooling and power consumption issues, it has two external PCIe power connector AFAIK.
This was indeed a stop gap product when TSMC ran into fabrication difficulties on the 40nm chip. There were heat issues with the reference coolers designed supplied by ATI thats why most went with a better design. Some cards do come with twin 6 pin pci-e power requirements (not this one). However they do not require both to be used, some manufactures included this if people were using multi rail PSU to spread the load.