Comparing GPUs across architectures and tiers is crucial when deciding which one to use for real-world needs. The most relevant metrics for comparison are core count, FLOPS, VRAM, and TDP. Core count can vary depending on the type of cores, such as CUDA, Tensor, or Ray-tracing cores. FLOPS measures the performance of a GPU at a specific precision, with higher precisions resulting in lower counts. VRAM is essential for model serving, with bus size, clock speed, and memory type (GDDR or HBM) being important factors to consider. TDP refers to the maximum amount of electricity a GPU draws while running, affecting its operating cost and price as an end user. When choosing a GPU, it's essential to consider these metrics and understand how they impact performance and cost.