> Is there any reason for them to stay with 5.25 or 3.5 inch design for a datacenter? > Why not go back to 8 inch for massive surface area? Or is that too much

> Is there any reason for them to stay with 5.25 or 3.5 inch design for a datacenter? > Why not go back to 8 inch for massive surface area? Or is that too much mass to spin. One problem AFAIK is that larger disks wobble too much, more the faster they spin. Which is why if you break open a 3.5" 15k drive you'll see that the platters are more like 2.5", and a lot of wasted space. For 7.2k you can use bigger platters, but how much bigger? I doubt 8" is feasible. Of course you can reduce the rpm further, but that has downsides too.