So far I'm not having the best of luck with this, I'm afraid. I did find a seller on eBay who has what appears to be your same board for sale and it has a fairly clear shot of your destroyed IC.

PNY GeForce GT 730 2GB DDR3 PCI-E Graphics Card- VCGGT7302D3LXPB

According to their picture the IC in question is labelled Q7. Typically a "Q" label is used for transistors, but we're looking at a part with 8 pins rather than the more expected 2 or 3. I can't make out any kind of labelling on the IC though. I'll keep looking; a set of schematics would be invaluable right now though.