I accidentally crippled my 4x RTX 3090 LLM rig with a hidden PCIe 2.0 x4 slot and fixing it doubled Mistral 128B performance
A user building a multi-GPU setup for local LLM inference discovered a significant performance bottleneck caused by a misconfigured PCIe slot. One of the four RTX 3090 GPUs was incorrectly placed in a slot that only supported PCIe 2.0 x4 speeds, severely limiting its bandwidth. After reconfiguring the GPUs to utilize their full PCIe capabilities, the user observed a dramatic increase in inference speeds, with Mistral 128B performance nearly doubling. AI
IMPACT Fixing hardware bottlenecks can significantly improve local LLM inference speeds and efficiency.