What graphics card would equal Geforce 9800 GT SLI?

Raw compute power says a 64bit GT730 can match a pair of 9800GT.

Certainly wouldn't invest in anything less then a GTX750 at this point. Rather difficult to get direct comparisons of cards so far apart. The 9800GT wouldn't even run some of the modern gaming benchmarking titles, so you have to rely on synthetic tests, and usually not the same test...
 
Ah, same GPU was re-branded as the GTS 240 through GTS 250 with varying memory and clock speeds. Compares directly with Intel HD 530 (6th core series) and the R7-250.

9800 GX2 which was a pair of 9800GTX on a single board is rated just slightly under a GTX750 for gaming performance by Tom's.