Hi Rengar,
The S5720 switches have only one bucket, now the S5735 have two buckets and each of the size of 4.
If the has is reached to one of the buckets and they are full, the system automatically calculates the hash to the seconds bucket.
So the result is the same with the size you configure to 8 on s5720.
The reason why the S5735 does not has the hash bucket function it is because it has two fixed buckets, each of size 4. They cannot be modified.
I hope it helps!