RTX 3090 vs RTX 4070 Ti

The RTX 3090 variant delivers 35.6 TFLOPS dense FP16 and 35.6 TFLOPS dense FP32 while the RTX 4070 Ti variant delivers 29.1 TFLOPS dense FP16 and 29.1 TFLOPS dense FP32. This dense FP16 advantage of 35.6 TFLOPS over 29.1 TFLOPS allows the RTX 3090 variant to complete matrix operations in training loops at a higher rate than the RTX 4070 Ti variant when sparsity features remain disabled. Memory bandwidth at the family level of 936 GB/s for the RTX 3090 versus 504 GB/s for the RTX 4070 Ti directly limits sustained data movement during large batch inference. The higher bandwidth on the RTX 3090 family supports larger batch sizes before memory stalls occur compared with the RTX 4070 Ti family. TDP values shared at 350 W for the RTX 3090 family and 200 W for the RTX 4070 Ti family determine cooling and power delivery requirements independent of the memory capacity difference.

The RTX 3090 variant with 24 GB memory capacity suits LLM training runs that require storage of full precision weights and activations beyond the 12 GB limit of the RTX 4070 Ti variant. Its 936 GB/s memory bandwidth supports larger batch sizes during fine tuning sessions where the RTX 4070 Ti variant would require gradient checkpointing to fit within 12 GB.

The RTX 4070 Ti variant with 200 W TDP fits into systems where power delivery and cooling capacity cannot accommodate the 350 W TDP of the RTX 3090 variant.