[edgesrazor]

I'd been doing my own research on viability of mining on Amazon, and I posed a question on the AWS forums asking how it's possible the spot prices could be going so high. There's instances going anywhere from 5-20 times their On-Demand prices. At this time, no one's answered it, so if anyone here knows, I'd love to hear why someone would pay $10.00 per hour for an instance they can get On-Demand for $2.40.

[topynate]

I don't know, but I can speculate with the best of them: Someone posted on a bitcoin forum that they were doing this, showing how they were bidding on spot prices etc. A bunch of people raced to get in on some free money ASAP, of whom a significant proportion neither did the expected value calculation nor realised that it was possible to rent at a flat rate! Crowd mentality, in other words.

[michaelt]

One pricing strategy I've heard of goes like so:

No rational person would bid above the on demand price, so the spot price will never rise above the on demand price. Therefore if I bid just above the on demand price I'll never be outbid, and I won't have to deal with automating the switch from spot to on demand instances.

Needless to say, this logic is wrong.

[edgesrazor]

Funny you should mention that. There was a blog post I had read where they were discussing an unfortunate AWS customer who bid $999.00/hour for Spot instances thinking it would protect their running servers from shutting down. Little did this person realize, Amazon - unlike eBay - doesn't just accept the next highest bid, they accept THE highest bid. They were running a Spot instance for an entire month at $999/hour. Ouch.

[zwily]

That's not true - the price you set is the max price you're willing to pay. If your price is higher than the current spot price, you pay the current spot price. The blog post author must be mistaken somehow.

[michaelt]

What do you suppose is displayed when there are no spot instances available, because all resources are being used for on demand instances or there's some problem with the spot market system?

[paulhodge]

One guess, maybe the spot price is controlled by some sort of predictive algorithm, and the algorithm got totally confused by the recent load? It might not be the case that people are actually paying that price.

[edgesrazor]

That's what I assumed, but if you look at the history, the prices have been trending like this for over a month now.

[apw]

It's possible that someone has found a way to speed up scrypt. We could solve for a lower bound on what that speedup must be.