Linus Torvalds called hard drives evil, nasty platters of spinning rust in an interview this week, while saying he likes SSDs.

I didn’t say it. He said it. Though it’s no secret that I like SSDs too.

And let’s face it: SSDs are big enough and cheap enough now. The computer I use at work has a 160 GB platter of spinning rust in it. It has Windows 7, Office 2010, and an assortment of other software on it. Only 111 GB of that platter of spinning rust is allocated for my use, and 81 GB of that is free.

I see two options for replacing the next-to-last bastion of 1970s technology in that machine: A 120 GB or 240 GB SSD. Going to 200 GB would make the drive more future-proof and increase its life expectancy. I haven’t completely worn out an SSD yet, but I did run a 40 GB OCZ Vertex drive filled to 90% capacity for about two years, and SSDlife didn’t think the drive had more than a year left in it. The 100-120 GB drives I purchased a year ago, meanwhile, still have nearly all of their life expectancy left.

So I’d advocate going the extra mile and ponying up the $120 or so for a high-quality 240 GB SSD, but if buying 120 GB SSDs for $70 allows you to deploy 90% more of them, there’s an argument for going that route, too.

Yes, those drives cost twice as much as conventional platter drives that have 10 times as much storage capacity, but that storage capacity is going to either sit unused, or it’s going to be abused and end up storing employees’ collections of music and movies, which are a legal and security liability.

If employees want to listen to music at work, they can buy a Sandisk Sansa Clip. It costs $30 and takes up less space than a set of keys. It has a micro SD slot for expansion and keeps MP3s off corporate networks.

And when running business applications, the biggest bottleneck in systems anymore isn’t the CPU and the memory. I have a two-core system right now; for a while I had a four-core system at a previous job and two of those cores spent most of their time looking for work to do. The biggest delays I experience are waiting 30 seconds for Word or Excel or Visio or Powerpoint to load.

An SSD cuts through that last remaining bottleneck, cutting down on frustration and increasing productivity. Many businesses spend $120 on a second monitor to increase productivity; that $120 SSD is a similar enhancement.

But the SSD also decreases power consumption by about two kilowatts per year, reducing the power consumption of the computer and the air conditioner that has to cool the building. The power savings is only a few dollars per year per machine, but it is a savings.

The bigger savings is in the life expectancy of the machines. Realistically, an SSD-equipped machine can be useful for 2-3 years longer than a machine without one. My personal laptop is six years old, but with a modern SSD in it, I’m perfectly happy using it right now.

If a computer costs $600 and takes two hours to deploy at a cost of $50 per hour, a $140 SSD saves $560 per seat–beyond the power savings.

In corporate environments, SSDs are an idea whose time has come.