AWS Certified Solutions Architect - Professional 2020

Sign Up Free or Log In to participate!

Standard RI vs Convertible RI

This question is from your simulator.

=== question  removed and rephrased ===

Looking at a sample question. There is a question where you need to choose between ease of operation and value. The prefered answer relies on moving the RIs between Regions. However I don’t believe that is an option as RIs cannot be moved between regions. Can someone advise if there is actually a way to move RIS between Regions

The correct answer says "Purchase a 1 year Convertible RI for each EC2 instance, for 2 consecutive years running".

I think "Purchase a 1 year Standard Zonal RI for 3 years, then sell the unused RI on the Reserved Instance Marketplace" should be the correct answer.

Reason - neither Convertible nor Standard allows moving regions, hence buying a Convertible RI won't help if you want to move region. Since Standard is both cheaper than Convertible and sellable, it makes more sense to buy Standard and sell it when it no longer suits your needs. Otherwise you are stuck with unusable premium priced Convertible RIs.

What do you think?

2 Answers

Hello Eric,

As noted before posting questions and answers is not acceptable on the site. and we are cracking down on the process.
It is quite possible to ask what you are asking without posting the question.

Coming back to the question.
You assessment look about right. In our AWS Exam prep course Mattias teaches a question answering approach which is specifically designed to help you avoid the intentional traps that AWS sets. At the core of it is knowing the services well and as soon as you spot an un-truth in an answer you eliminate the answer regardless of how otherwise attractive it might be.

Remember to look at every answer and assess if it has an aspect that is untrue or cannot be done. If you have to make a choice, an answer that simply cannot be done must be eliminated.

Is there something in the other answers that would eliminate Standard RIs ? 

Best of skill


Moderator & Coach


PS As part of your thinking about this, have you calculated the difference in cost? You would not be expected to do so in an exam, but you might find it informative as part of general study.

Eric Zhang

Thanks for your feedback. No, the other two answers were obviously wrong. One said sell the unused Convertible RI. One said buy Scheduled RI. I haven’t calculated the cost, but in general sense instances are commodities i.e. a buyer would not care who the seller is, based on that logic if you price your unused standard RI at a small discount to AWS’s standard RI price you should be able to sell it at a small loss. This effectively turns your standard RI to on-demand.

Eric Zhang

If I’m not allowed to mentioned questions that are provided as part of the course, how am I supposed to feedback questions like this one to ACG?


This is a problem that we are working on fixing. I will contact you off line, possibly your perspective can help with finding a better solution. I will email you later today.

Hi Eric,
The exam questions won’t test your ability to calculate. However in a real world situation you should check the TCO of each option. I mention this because a couple of years ago I was working on a migration where we felt that changes in hosting might be needed after 18 months and so had a similar problem to this scenerio.

The TCO costs worked out that we were better to buy long term RI up front knowing that we might abandon them part way through.  The short term and convertible RIs were more expensive in that business case, and since we we not certain that we would even be changing there was an extra incentive to go with the long term low cost solution,even if we had to abandon the RIs.

Also keep in mind that you cannot sell RIs unless you have a US based bank account.  Which in reality means that for anyone outside the US that is not an option. 

If this is one of our questions I will go find it and check response and how I would solve it.  

keep going

Moderator & Coach

Sign In
Welcome Back!

Psst…this one if you’ve been moved to ACG!

Get Started
Who’s going to be learning?