Oh, and by “full seek” I mean the time it takes to read the max block number (inner diameter) right after reading the min block number (OD) subtracting rotation

Oh, and by “full seek” I mean the time it takes to read the max block number (inner diameter) right after reading the min block number (OD) subtracting rotational delay. You can do this test yourself with fio —readonly and root access to a hard drive block device, even if it’s mounted. (good luck reading any files while the test is running, but no damage done) Pick a variety of very high and low blocks, and the min delay will be when rotational delay is close to zero.