

Show HN: AWS EC2 On-demand vs. Reserved Interactive Price Comparison - promptcloud
http://promptcloud.com/ec2-ondemand-vs-reserved-instance-pricing.php

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forbes
This is simple but excellent. AWS should have graphs like that on their
calculator page to help people decide how long it will take for their
investment in a reserved instance to get ahead of on-demand (or another
reserved instance plan).

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bhauer
Perhaps it's pessimistic of me to say so, but I doubt Amazon wants you to be
able to appreciate the price relationship with quite this degree of immediacy.
Sure, the data is there for you to plot yourself or use a third-party tool
such as the OP's. But if you naively select an on-demand instance (the
default) where a dedicated instance would be more advantageous for you, Mr.
Bezos is made a tiny bit happier.

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nirvdrum
Maybe, but the heavy reserved instances come with a required hourly
commitment. If you buy one, you have to pay the 24/7 hourly usage fee
regardless of whether you're actually running a server. That strikes me as the
bigger "gotcha."

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promptcloud
There is one more "gotcha" if you dig deeper. That is the drop in EC2 prices
and Amazon in general has been vague about passing on the benefits of price
drop to old reservations (
<https://forums.aws.amazon.com/message.jspa?messageID=325153> ) . We even
thought about adding speculative price drop and then do the comparison, but
dropped the idea. It will be interesting to hear the take of HN community on
this ..

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ealexhudson
I'm not sure how these calculations are correct - I have eu-west-1 set up, and
the price for 1yr heavy reserved is fixed. But the AWS pricing still has an
hourly rate against it. The final cost looks right, but the initial cost (eg.,
taking out the reservation but never running the instance) should just be the
setup cost I think?

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Eclyps
When you reserve an instance, it doesn't entirely eliminate the hourly cost to
run it. What you are essentially doing is paying a large chunk up-front in
exchange for a _heavily_ discounted hourly rate, which ends up saving you
money by the end of your 1 - 3 year contract.

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ealexhudson
Isn't that what I'm saying? That the cost should increase, albeit at a much
more gradual rate, from the start of the term to the end?

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promptcloud
Heavy utilization reservation is different. See this page
[http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/InstanceS...](http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/InstanceStorage.html)

Quote from the page above " Light and Medium Utilization Reserved Instances
also are billed by the instance-hour for the time that instances are in a
running state; if you do not run the instance in an hour, there is zero usage
charge. Partial instance-hours consumed are billed as full hours. Heavy
Utilization Reserved Instances are billed for every hour during the entire
Reserved Instance term (which means you’re charged the hourly fee regardless
of whether any usage has occurred during an hour). "

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ealexhudson
Full marks for demonstrating that the AWS pricing schedule can continue to
hold surprises :-)

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jareds
Is there any plans on making this tool accessible? I'm a screen reader user
and the sliders don't appear to work with Firefox and Jaws.

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promptcloud
Sorry for not looking into it earlier, but our own expertise in UI is limited,
will seek help and try to fix it ASAP.

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Eclyps
I like the idea, it's just a bit difficult to use for what I'm getting out of
it. Simple things like making clear what the "number of days" slider means (it
didn't take long to figure it out, but I had to use the context to draw my
conclusion). I'm used to seeing my instances in the typical "t1.micro,
m1.small, m1.medium, etc" format, so I was a bit thrown off by the "Instance
Category" dropdown.

It would also be nice to have values on the x axis of the graph so I can see
exactly when certain thresholds are crossed - as of right now I'm just
assuming that the max x-value is my specified days * 24.

Again, cool idea, but I'd be more inclined to hit up the AWS Cost Calculator
(<http://calculator.s3.amazonaws.com/calc5.html>). It's ugly, but it allows me
to quickly add many resources from all of the AWS services for a total monthly
cost.

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promptcloud
Thanks for the feedback. We are doing the "t1.micro, m1.small .."translation
right now. (Edit : changes pushed)

X axis value seems to be some browser issue. On some browsers it shows up only
at reduced zooms. Will fix it.

Also, we are not trying to replace AWS cost calculator. It was more like
putting our own dog food out to answer the question, that at what point/usage
is the reserved instance better than on demand.

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waterside81
Cool tool. One suggestion, in the dropdown where you list the types of
instances, can you append the abbreviations that AWS uses (e.g. M1-small,
M2-medium, M3-large). I'm sure I'm not alone in referring to instances by
those codes rather than their full names, which I seem to always forget.

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promptcloud
Thanks for the feedback, doing it. Will upload the new version in 20 min or
so.

Edit : changes pushed.

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hornbaker
Also useful: [http://mikekhristo.com/ec2-ondemand-vs-reserved-instance-
sav...](http://mikekhristo.com/ec2-ondemand-vs-reserved-instance-savings-
calculator/)

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MrMike
glad to see this still helps folks =)

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nirvdrum
If you're taking feature requests, it'd be really handy to see pricing
breakdowns for Windows instances as well. They have a different breakeven
point than the Linux ones.

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promptcloud
Sure, will add it in a couple of days. Wanted to get feedback from the
community before adding more use cases.

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Sealy
That very cool, something that many of us will find useful.

Feedback: The top bar folds over when the browser window is resized (looks
like anything less than 1024 px). The page then starts to overlap on itself
blocking out content at the top.

How did you code up the graphing part? HTML5?

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sp332
Sweet project :) The page layout seems to break for windows narrower than
about 900 pixels, though.

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promptcloud
Thanks for the feedback. We'll fix that soon :)

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imperialWicket
This is a nice tool, another one (and a point of comparison/inspiration) is at
<http://whichinstance.com>.

EDIT: fixed autocorrect

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photorized
For 30 days 24hr scenario, "Total cost of instance" graph is showing bogus
numbers on the iPad. Let me know if you are unable to replicate and need a
screenshot.

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promptcloud
Yes that will be good, please send the screenshot to info "ta" promptcloud.com

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photorized
Done.

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eistrati
Check this out as well: <http://www.awsnow.info/#ec2>

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dhendo
It would be interesting to see the current spot instance price plotted as
well.

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grosskur
I recently made an app to graph spot prices:

<http://ec2price.com/>

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if_by_whisky
The sliders dont work on mobile.

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promptcloud
Which browser are you using ? we tested on quite a few combinations but might
have missed some.

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ProCynic
fails for me with android chrome beta 28.0.1500.21 on android 4.2.2

