Revit Personal Accelerator FAQ

Solution:

What is the Revit Personal Accelerator (PAC)?

What is the default location of the Revit Personal Accelerator?

C:\Program Files\Autodesk\Personal Accelerator for Revit\RevitAccelerator.exe

Where does the Revit Personal Accelerator (PAC) store data?

%LOCALAPPDATA%\Autodesk\Revit\PacCache

What does Revit Personal Accelerator do, and how does it work?

• Revit Cloud Worksharing (RCW) consists of the cloud service, which sends and receives streams of element data from the cloud to your local model.
• When you open a Revit Cloud Worksharing or Revit Cloud Model, you're opening a local model based on a central model located on your C drive, which is based on the version in the RCW service. This central and the associated local lives in your CollaborationCache Folder (By default: %LOCALAPPDATA%\Autodesk\Revit\Autodesk Revit ####\CollaborationCache)
• Most of the interaction between the model on RCW and your local central is performed by the Personal Accelerator for Revit (PAC).
• PAC pulls the incremental changes on RCW from the cloud to the local disk, pinging the RCW service periodically (approximately every 2 minutes) to retrieve the latest version from the cloud. This version is compared to the locally saved version, and any data streams between the two are then downloaded. When a user attempts to sync, Revit requests the current version from RCW, compares it with the version in PAC, and uses the PAC data to tie the content into the local central, thereby weaving the data streams into the file as needed. This process is referred to as prefetch, and ensures that the system actually syncs faster than what you get with Revit Server and sometimes even local network - all the data is local before you need it - Revit gets to concentrate on just building its file rather than worrying about sending content between it and a file elsewhere.
• PAC also has a second way of working, which we'll call "Active". It is used in active models where changes may be occurring faster than PAC can process them, or when opening a model for the first time. In this case Revit will compare the local central version (say version 3, or version 0 if it doesn't have anything yet) to the version in RCW (say version 10), and will then ask PAC what it has (say version 5, or version 0 if this is the first open). Revit will then start downloading the 'first' data streams from RCW (version 4 or 1), while PAC starts on the last data streams (version 10). PAC will then progress backward (version 9, 8, 7...) while Revit counts forwards (2, 3, 4, 5) until the full data set is local. This ensures the data in RCW is transferred to the local system correctly at twice the speed of machines where PAC isn't running

What is the risk of using Revit Cloud Worksharing (RCW) without the Revit Personal Accelerator (PAC) running?

• A nonfunctioning PAC, combined with RCW, can cause varying degrees of issues (from mild performance degradation to file corruption) depending on the speed and intensity of changes in the worksharing model. Revit expects a partner service (namely PAC) to work with RCW, and if that partner isn't available, then 100% of the process is performed locally. This can lead to slow performance or even sync loops, as Revit may not be able to 'catch up' to the RCW version, which in turn can result in corrupted models.

How can I confirm that PAC is running and working on my machine?

• If it is running, you will see this icon in the Windows System Tray, and it will also be listed as RevitAccelerator.exe in the Windows Task Manager.
• Also, you can check the PAC logs to confirm it is functioning properly (the last timestamp in the file should have a time within a few minutes of the current time).
  • The PAC log files can be found in the following folder location: %LOCALAPPDATA%\Autodesk\Revit\PacCache\Logs

What triggers Revit Personal Accelerator to start on a workstation?

• Revit Personal Accelerator is a background process designed to run continuously in the background as long as Windows is running.
• Therefore, the RevitAccelerator.exe service should be set to run on the log-in/startup of the operating system. To do this, set the following: Windows > Task Manager > Startup > RevitAccelerator > Enable.
• The start of PAC is not connected to any other Autodesk products - meaning: If it is not running, nothing will trigger a start of that, but a manual start from C:\Program Files\Autodesk\Personal Accelerator for Revit\RevitAccelerator.exe

Does the newest version of Personal Accelerator support all versions of Revit?

• The latest version of the Personal Accelerator is compatible with all versions of Revit.

Should all team members using Revit have the same version of the Personal Accelerator?

• Best practice is to have everyone on the same Personal Accelerator to avoid any possible issues.

Where does the Revit Personal Accelerator store config settings?

• The Revit Personal Accelerator configuration file is stored in the following location: %LOCALAPPDATA%\Autodesk\Revit\Revit Personal Accelerator

Does Revit Personal Accelerator clean old cache data?

• Revit Personal Accelerator cleans the cache folder automatically on a first-in-first-out (FIFO) basis when either of the following occurs:
• • The cache folder reaches 98% of the chosen limit in size.
  • When the number of models tracked (default 200) is reached.