Tableau Reader will be the same speed as Tableau Desktop with an extract. Tableau Server is usually faster than Tableau Desktop unless it is overloaded or has a slow connection to your data source. What's your data source, how big is it, where is it located relative to Server, and are you using an extract?
I'm personally using Tableau Desktop 2018.2. A live connection. When I have the Workbook opened on my desktop and go to "Data Source", it says "Connected to Tableau Server as Tadd Wagner."
I'm not sure of exact size. I think it's coming from SQL server.
When I went to publish, I did get this note by the way:
"Warning: Server is running an older version than your copy of Tableau Desktop. The workbook will be downgraded on the server and may lose some functionality..."
The warning about Server being older than Desktop shouldn't affect performance, just functionality, and your dashboard would probably break completely if you were using unsupported features.
Try pulling an extract of your data into Desktop and confirm it is still fast (extracts are almost always much faster than live unless they are way too big to load into memory). You're going to have to use extracts with Reader anyway. Then publish the workbook with extract to Server. If that is still slow, then the issue is an underpowered server. If that is fast then the issue is a slow live connection from Server to SQL.
You can set a refresh schedule for the extract so users get fresh fast data.
Try pulling an extract of your data into Desktop
What is the best way to do this? I downloaded the workbook from server and then opened it, went to data source, and clicked the box next to Extract instead of Live. it has elapsed time of 5 mins and still going.
Extracts can take a while to generate but are still faster to use unless they get too big. You can make them faster to generate and smaller in size by adding some extract filters (click the Edit button to the right of Extract). If your dashboard only shows recent data, you could restrict your extract to recent data only.
Extract filters are different than Data Source filters which you access by going farther to the right and using the Add button. DS filters are global filters that are applied to the live data or the extracted data after the extract is made.
Can you think of a reason your Server -> SQL connection would be slower than Desktop -> SQL?
Okay, guess I should have started off by calling our IT dept.
I was told this is a Tableau data source (vTab?) and even though I set it up as a live connection, it should be acting as an extract because IT has it setup to update only at specific times. There are a lot of filters in this dashboard and apparently that's what can cause the slowdown when opening it online instead of on my desktop? Thanks for all the help, Zach. Sorry, this terminology is all a bit new to me. It does seem odd to me that it would work (filters and all) on desktop and would be much slower online.
EDIT: On a third look, it seems that it took significantly longer to pull the dashboards up on Server, but once it finally pulled up, performance is similar to desktop. Man, must be a Friday afternoon. Doh!
Thanks again Zach.