WAN Acceleration 2008 Hotfix

This hotfix improves performance of save to 2007 DWG format when running in a WAN Acceleration environment.

Description of Problem

WAN acceleration technology typically relies on data-deduplication as a significant part of accelerating data transfer. The 2007 DWG format is written to disk with a type of error-checking that has the side-effect of nearly every byte of the file changing during full-save, even if little was changed. WAN accelerators fail to deduplicate the 2007 DWG data and must transfer nearly all bytes in the 2007 DWG file. This results in a slow-down during full-save when working over a slow WAN.

This hotfix will make a small change in the way the 2007 format DWG files are written to disk such that WAN acceleration hardware will be better able to deduplicate the 2007 DWG data; this will provide some performance gains for SAVE operations when users are saving across a WAN acceleration environment. The resulting 2007 DWG file will be readable whether or not others have this hotfix, but to achieve the best performance everyone working on the same DWG should install this hotfix.

After intalling the hotfix, you must set the Windows environment variable, ACADCOMPRESSIONMODE to 1 for it to have effect.

Note: For AutoCAD, you can often get performance gains in QSAVE operations by setting the ISAVEPERCENT system variable to 100. Using a value of 100 will maximize the chance that a QSAVE operation will use incremental-save rather than full-save. (WAN accelerator technology is able to show good performance in deduplication of 2007 DWG format files when incremental save takes place.)

Affected Products

• AutoCAD^® 2008 SP1
• AutoCAD LT^® 2008 SP1
• The following Autodesk^® products utilizing AutoCAD 2008 SP1:
  • AutoCAD Architecture 2008
  • AutoCAD Civil 3D^® 2008
  • AutoCAD Civil 3D Land Desktop Companion 2008
  • AutoCAD Electrical 2008
  • AutoCAD Land Desktop 2008
  • AutoCAD Map 3D 2008
  • AutoCAD Mechanical 2008
  • AutoCAD MEP 2008
  • AutoCAD OEM 2008
  • AutoCAD P&ID 2008
  • AutoCAD Raster Design 2008
  • AutoCAD Revit^® Architecture Suite 2008 ⁽¹⁾
  • AutoCAD Revit MEP Suite 2008 ⁽²⁾
  • AutoCAD Revit Structure Suite 2008 ⁽¹⁾
  • AutoCAD Utility Design 2008
  • Autodesk^® Inventor™ 2008 ⁽³⁾
  • Autodesk Inventor Suite 2008 ⁽³⁾

⁽¹⁾ Apply this hotfix only if the installation includes AutoCAD 2008.
⁽²⁾ Apply this hotfix only if the installation includes AutoCAD MEP 2008.
⁽³⁾ Apply this hotfix only if the installation includes AutoCAD Mechanical 2008 or AutoCAD Mechanical Desktop 2008.

Installation Instructions

To Install the WAN Acceleration Hotfix

You must have administrative privileges on your Microsoft^® Windows^® operating system to complete the installation process.

NOTE: This installation requires you to modify an installed product, which may cause Windows security warnings to display. For all Windows security warnings that display during installation, click Continue.

To replace the acdb17.dll File

1. Close all software applications.
   
2. Navigate to the folder where your Autodesk product was installed, for example, C:/Program Files/AutoCAD 2008.
   
3. Right-click acdb17.dll. Select Properties.
4. Click the Version tab and confirm the file version.
   
   • If the version number is 17.1.219.0, then proceed with the installation.
   • If the version number is less than 17.1.219.0, then you must first install AutoCAD 2008 Service Pack 1 or corresponding service packs for other affected products before proceeding with this installation.
   • If the version number is 17.1.219.21 or greater then this hotfix has already been applied and you do not need to proceed with the installation.
5. In the folder specified in Step 2, right-click acdb17.dll and rename it acdb17.bak.
6. Based on the version of your product, double-click WAN_Accelerator_Hotfix_2008_32bit.zip or WAN_Accelerator_Hotfix_2008_64bit.zip and unzip the acdb17.dll to the folder specified in Step 2.
7. Right-click the new acdb17.dll and select Properties. Click the Version tab and confirm that this file is version 17.1.219.21.

To set the ACADCOMPRESSIONMODE environment variable

1. On Windows XP
   • Right-click My Computer, and then click Properties.
   • Click the Advanced tab.
   • Click Environment variables.
   • Click New to add a new system variable name and value.
   • Set the Variable name to ACADCOMPRESSIONMODE
   • Set the Variable value to 1
   • Click OK until you return to the desktop
2. On Windows Vista
   • Right-click My Computer, and then click Properties.
   • Right-click My Computer, and then click Properties.
   • Click the Advanced system settings link.
   • Click Environment variables.
   • Click New to add a new system variable name and value.
   • Set the Variable name to ACADCOMPRESSIONMODE
   • Set the Variable value to 1
   • Click OK until you return to the desktop

To Uninstall the WAN Acceleration Hotfix

1. In the product installation folder
   • Delete the acdb17. dll file that you downloaded.
   • Restore the file you renamed to the original name. See To Replace the acdb17.dll File, Step 5.