Amazon Web Services is expensive, if you compare them with the overselling dedicated server market.

Automattic’s Matt Mullenweg responded to Joyent’s point on grid, showing how big a package they can get from LayerTech with under $2.5k per month. It’s indeed quite an impressive list — 15 boxes sharing 27Gb of RAM, 500Gb of RAID’ed storage and 18Tb of public data transfer. At the end he asked:

What do you guys think? Anyone want to work out what the same would cost on Amazon? Which would you go with?

Let’s take out the calculator.

Amazon Web Services is Expensive!

We will just look at the bandwidth cost alone. How much does it cost to pump out 18 terabytes of data from Amazon (EC2 or S3)? At the current rate of 20cents per Gb, 18Tb is going to cost you $3,600! It is already more expensive than LayeredTech’s offering, and we are not yet counting storage and computation power yet!

Sure, your 500Gb file server would only cost $75/month on S3. Running 26 instances of EC2 24×7 would cost around $1,900 per month (26 because Matt’s setup has 12 dual core + 2 single core servers). 45Gb of RAM total, but it still falls short of total amount of “CPU power”.

But the bandwidth cost?!

Amazon: You (only) pay what you have used

I guess the main difference is, most web hosting companies oversell. Most LayeredTech dedicated servers come with 1.5Tb of monthly data transfer, but I am sure many servers actually don’t use anywhere near that.

When Linden praised Amazon S3 for saving the Second Life download, my initial reaction was — “hey that’s crazy”. 1Tb of data transfer? $200 on S3, where as my $100 LayeredTech dedicated server would be sufficient! Then I realised, someone else is actually subsidizing me for using all my allocated data transfer.

S3’s model is also more flexible when the usage pattern is less than regular.

For example, the following month traffic dropped to 500Gb. With a dedicated server however, it will still be $100 (with CPU mostly ideal as file servers are IO bound). With S3, you only pay what you have actually used — $50.

So is it expensive?

Back to Matt’s question — I think AWS can be more expensive when you try to spec out something similar to your average dedicated server offerings. However I do not think Amazon is pushing AWS as a “cheaper dedicated server replacement”.

Instead, AWS is making CPU power, storage, bandwidth, etc a “commodity”. They are “cheap enough”, yet easy and fast to provision, deploy and use. For example, you might be capable to build an economical power generator in your own backyard, it is usually more convenient to just connect to the electricity grid — it will make your life much easier, and much more capable to scale up and down with your demand.

Update

Err. Fixed a few spelling mistakes as I initially wrote this post way too late at night yesterday.

Also with reflection on what Isabel has said, AWS scales great both ways. Not only that it will cost you less during the “not-so-busy” season, it also gives you flexible bandwidth without the need to deploy additional servers during busy seasons. Managing these servers take time, and time is expensive.

At the end, a fleet of 15 servers might cost $2,500/month. A good sysadmin costs much more than that.