Previously, Sapphire's HD 7750 was the lowest ranked card to offer the modern AMD graphics architecture, with the HD 6600/7600 series cards and below relying on the older VLIW5 design instead. The HD 7730 is running a similar GPU to the other HD 7700 series cards, known as the Cape Verde LE.
This 28nm GPU is basically a chopped-down version of the chip used by its HD 7700 series brethren, giving AMD something to do with the failed Cape Verde GPUs that didn't pass muster the first time around.
The HD 7730 has about 384 shaders compared to 512 in the next card up the stack, the HD 7750. It also has half the ROPs and eight fewer texture units. It's a pretty similar story with regards to the GPU and memory clockspeeds. The 800MHz base clock (there's no boosting this low down the stack, people) is the same as its big brother's, and once again we're looking at a 1,125MHz memory clock.
With the clockspeeds and memory bus the same as the HD 7750's, the actual GPU make-up is the only thing that's changed.
We understand that AMD wants something to do with its failed Cape Verde GPUs, and ordinarily dropping them into a new card lower down the stack wouldn't be a problem.
The issue is that there are so many levels of graphics cards these days, there's generally very little between them in terms of price and architecture. There's a very small price gap between this HD 7730 and the HD 7750, and only marginally more difference if you move up to the HD 7770. You can get adequate gaming performance from this card if you drop some of the more intensive graphics settings down a couple of notches, but you're sacrificing a good deal of performance for a very small saving.
DirectX 11 tessellation performance
Heaven 4.0: Frames per second: Higher is better
HD 7730 1GB: 4.7
HD 7750 1GB: 6
GT 640 REV 2 1GB: 3.8
DirectX 11 gaming performance
GRID 2: Frames per second: Higher is better
HD 7730 1GB: 40
HD 7750 1GB: 53
GT 640 REV 2 1GB: 45
Bioshock Infinite: Frames per second: Higher is better
HD 7730 1GB: 15
HD 7750 1GB: 20
GT 640 REV 2 1GB: 17
The HD 7770 would still be our card of choice in this price range. If the HD 7730 was GCN built into a small form factor card like the new(ish) GT 640, and came with the same low power requirements, then it could maybe justify itself as a decent discrete option for teeny-tiny PC gaming. As it stands though, it's a relatively chunky card.
It's not the same as a full-scale HD 7770, but it's not going to sneak into any serious small form factor build. It's the cheapest you'll find the GCN architecture, but the HD 7730 1GB doesn't do enough with it to discourage you from saving up for another week and plumping for something like the HD 7770.