This is still pretty early on in emulation so the higher CPU is the way to go. I wouldn't really expect much out of anything without a i7 x700+ CPU. This is just the CPU i have i7 4790k. The 3570 is 500 points lower on STP though and that makes a big difference and the multicore is over twice as strong in a 4790k at stock speeds. So yes, just a small bump can make a huge difference.
Mobo: ROG Maximus Hero VII
CPU: Intel 4790k O.C. to 4.6 GHZ
GPU: EVGA 1070 O.C. 100 MHZ and 250 on Memory
Ram: 16 gigs DDR3 2133 MHZ Timings 9-11-11-31
HDD: Roms on Seagate Baracuda 1TB
Monitor: Gateway 24" 1920x1200 60 Hertz