nVidia GTX980 has 224GB/s bandwidth and 7Gbps memory clock. Its bus width is 256bit.
Can we calculate how much max/min data can be loaded in parallel from the GDDR5?
Can I get the answer from dividing 224GB/s by 7Gbps?
You've already got the answer. 224GB/s equals to 7Gbps x 256bit as
224==7*256/8
The bus width is the limit.