Because I had some issues to read games from a 16Gb SDCard with the H&B SM-4000 Genesis Emulator, I made some tests with another cards:
| SDCard | Size | Firecore compatibility |
| Transcend SD | 128Mb | PASSED |
| Memorymaster SD | 2Gb | PASSED |
| SanDisk Extreme III SDHC | 4Gb | PASSED |
| Silicon Power SDHC | 16Gb | FAIL TO READ GAME |
Anyway, the full Genesis romset should be 4Gb large unpacked, so who cares having a 16Gb compatibility?