Gemma 4 31B

User reports Gemma 4 31B Q5 at 20 t/s on two RTX 3060 12GB cards in llama.cpp, up from 14 t/s with layer splitting, a 42% gain. One card runs on PCIe x16 and the other on a PCIe 3.0 x1 riser; the user notes the fit and context are tight and that testing was limited while awaiting a PSU upgrade. On a rented 2x RTX 5060 Ti 16GB machine, L3.1 Nemotron Sunfall 71B IQ3_XS at 2k context with flash attention gave 20.7 t/s generation and 464.4 t/s prompt processing under tensor split, versus 11.7 t/s and 591.8 t/s under layer split. PCIe traffic during decode measured roughly 90-110 MB/s per direction, with load spikes above 4,000 MB/s.