How long does it take for AWS S3 to save and load an item?
<p>S3 FAQ mentions that "Amazon S3 buckets in all Regions provide read-after-write consistency for PUTS of new objects and eventual consistency for overwrite PUTS and DELETES." However, I don't know how long it takes to get eventual consistency. I tried to search for this but couldn't find an answer in S3 documentation. </p>

<p><strong>Situation:</strong></p>

<p>We have a website consists of 7 steps. When user clicks on save in each step, we want to save a json document (contains information of all 7 steps) to Amazon S3. Currently we plan to:</p>

<ol>
<li>Create a single S3 bucket to store all json documents.</li>
<li>When user saves step 1 we create a new item in S3.</li>
<li>When user saves step 2-7 we override the existing item. </li>
<li>After user saves a step and refresh the page, he should be able to see the information he just saved. i.e. We want to make sure that we always read after write. </li>
</ol>

<p>The full json document (all 7 steps completed) is around 20 KB. 
After users clicked on save button we can freeze the page for some time and they cannot make other changes until save is finished.</p>

<p><strong>Question:</strong></p>

<ol>
<li>How long does it take for AWS S3 to save and load an item? (We can freeze our website when document is being saved to S3)</li>
<li>Is there a function to calculate save/load time based on item size?</li>
<li>Is the save/load time gonna be different if I choose another S3 region? If so which is the best region for Seattle?</li>
</ol>