What if it wasn't a mistake? What if they did it on purpose because they thought no one would notice? I'm reminded of the 970 where 1/8th of the RAM was slower

What if it wasn't a mistake? What if they did it on purpose because they thought no one would notice? I'm reminded of the 970 where 1/8th of the RAM was slower which could cause uneven performance and Nvidia didn't bother to disclose it.