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Author here! Spot instance pricing is better than on-demand, but it doesn't include data transfer, and it's still more expensive than on-prem/Hetzner/etc. Data
by lebovic 4y ago
Author here! Spot instance pricing is better than on-demand, but it doesn't include data transfer, and it's still more expensive than on-prem/Hetzner/etc. Data transfer costs exceed the cost of the instance itself if you're transferring many TB off AWS.
For of our more popular AWS instance types I use – a c5a.24xlarge, used for comparison in the post – the cheapest spot price over the past month in us-east-1 was $1.69. That's still $1233.70/mo: above on-prem, colo, or Hetzner pricing. Data transfer is still extremely expensive.
That said, for bursty loads that can't be smoothed with a queue, spot instances (or just normal EC2 instances) do make sense! I use them all the time for my computational biology company.
- timmclean 4y agoFWIW, spot prices for c5a.24xlarge in us-east-2b and us-east-2c seem to have been under $0.92/hr for most of the last 3 months. So, assuming some flexibility on the choice of region, that would adjust your estimate to $0.92 / $1.69 * $1233.70/mo = $671.60/mo, which looks a lot more reasonable. Hopefully I did that math right. Data egress prices are definitely still ridiculous, I agree.
- lebovic 4y agoTrue! It sometimes drops even more, which definitely makes spot instances attractive. The r5.16xlarges had a ~80% discount and a <5% termination rate for while. Also, if all of scientific computing switched to AWS in order to exploit spot instance pricing, I don't think those market dynamics would stay the same. As an aside, I've had trouble created large clusters of high memory instances in us-east-2. They might have increased capacity recently, though.