It would be 273 GB/s (gigabytes, not gigabits). But in reality we don't know the bandwidth. Some ex employee said 500 GB/s.
You're source is a reddit post in which they try to match the size to existing chips, without realizing that its very likely that NVIDIA is using custom memory here produced by Micron. Like Apple uses custom memory chips.
You're source is a reddit post in which they try to match the size to existing chips, without realizing that its very likely that NVIDIA is using custom memory here produced by Micron. Like Apple uses custom memory chips.