Hey! Yes please dive in :) It can be a starting point for learning Rust ;)
MatMul is fine, the bottleneck is LayerNorm + Softmax gradients right now. Haven't been able to optimize them well yet.
i7-13700H, 2400 Mhz, 14 Core(s), 20 Logical Processor(s). It is using 12 CPUs which is good. And 160Mb memory.