Update: ATI has officially confirmed that it does not allow partners to overclock the HD 4770, at least not for the time being.

Asus is so far the only partner to announce an overclocked HD 4770 card. The card has reference cooling but it is overclocked to 800MHz for the GPU.

In addition to the reference clocked card which works at 750MHz for the core and 3.2GHz for 512MB of GDDR5 memory, Asus has launched a TOP edition which is overclocked to 800MHz for the GPU and 3.4GHz for the same memory.

This is a 50MHz overclock for both the GPU and memory, and Asus is currently the only partner that has an overclocked card, at least as far as we know. Another interesting thing is that Asus included its Voltage Tweak Technology with the Asus EAH4770 TOP card which raises the GPU voltage from 0.95V to 1.2V. This voltage boost is enough to raise GPU and memory frequencies from 800MHz to 971MHz and from 3400MHz to 4600MHz.

Both cards should be available as soon as Asus manages to get them to shops.