Hacker News Reader

Modern VRAM (GDDDR) runs at very high frequencies and very low latency. This makes the wiring between the RAM chips and GPU very tricky (they need to be short and the same length), so slots aren't an option. There were actually VRAM slots in some 90s GPUs.

View on HN

VRAM runs at high frequencies, delivers insane throughput, but the latency is not great. GPUs don’t need low memory latency. They have very high degree of parallelism. GPU cores switch to other threads instead of waiting for data from memory.

Here’s an interesting system with AMD Zen2 CPU and GDDR6 memory, salvaged from XBox: https://www.tomshardware.com/news/4800s-xbox-chip-shows-us-w... As you see, high latency of GDDR6 memory ruins the performance of CPU-running code.

Reply on news.ycombinator.com