You're not taking the increase in the number of servers into account. Seven times as many hard drives requires seven times as many servers[1], and those extra C

You're not taking the increase in the number of servers into account. Seven times as many hard drives requires seven times as many servers[1], and those extra CPUs and power supplies and cooling fans and motherboards and the extra RAM will consume far more than any power savings SSDs may give. [1]I was talking in the grandparent post about optimising for online gigabytes per watt. I'm assuming we still are, because SSDs are a huge win except for this instance. If we're talking about performance, SSDs are so much better than mechanical there's basically no comparison. Optimising for online gigabytes per watt, your servers will have the maximum number of hard drives installed, always.