======================================================================== ####### # # # # # # # # #### # # # ## # # ## # # # # # # # # # # # # # # # # # # # # # # # # # ### # # # # ## # # ## # # # #### # # # # # #### ........................................................................ # ##### # ###### # # # # ##### #### # # # # # # # # # # # # # # # # # # # # # # # # # # # # # # ####### # # # # # # ####### # # # # # # # # # # # # # # # # # #### # #### ##### # # ###### ======================================================================== ABOUT AUTOCAD PERFORMANCE (on IRIX): Many factors can affect AutoCAD performance on SGI-IRIX workstations. With different tests, different factors may be dominant. The default settings are usually fairly good, but it is quite common to get a 2X (or better) speed-up just by changing a few system settings. With any test, it is important to understand what it does, how it works and make sure it is repeatable. A big step along this way is to automate the test. AutoCAD can be automated through IRIX shell scripts, AutoCAD command scripts, AutoLISP source files and compiled ADS applications, or any combination of the above. AutoCAD has built-in timing support and can do just about everything automated. The worst "benchmark" scenario is to type in a few commands, look at a clock, hit Enter and then check the time when the task completes. AutoCAD's internal clock uses "wall-time". That is, it is the elapsed clock time from start to finish. Irix, unlike some operating systems, is fully multi-tasking. There may be 50 (or more) independent processes running: network activity remotely logged-in users print spoolers other background processes When running an AutoCAD benchmark test, the elapsed time may be increased due to other processes using CPU cycles while the benchmark was running. You will get faster times by taking the machine off of the network, shutting down un-needed processes, etc. However, in the "real world", this may not be practical. Also, you may want the benchmark results to reflect a "real world" environment. Obtaining maximum AutoCAD performance involves several tasks: 1. Choosing and configuring the right machine for your tasks. 2. Configuring the operating system to work optimally. 3. Configuring the application to work optimally. 4. Configuring the display driver to work optimally. 5. Integrating AutoCAD efficiently into the entire design cycle with collaborative tools. Optimum machine configuration: Physical memory: Autodesk recommended configuration: 32 MB on all Unix platforms. 8-16 MB on DOS and Windows platforms. If you notice faster performance on a 32MB Pentium vs. a 32MB Indy, realize you are using several times the recommended memory on the PC and the bare minimum on the Indy. You will want additional memory if you intend to work on large drawings. Consult the "AutoCAD Installation and Performance Guide" for guidelines. I recommend 64MB to start with, preferably in one bank of 4-16MB SIMMs to allow room for future expansion. Unlike most PCs, Unix workstations can make effective use of all the memory you can put in them. A quite way to see if more memory is needed is to launch the program 'gr_osview -a' and watch the various resource indicator displays while running AutoCAD. If you see a lot of CPU time spent waiting for swap (yellow bar) or the free memory indicator getting small (green bar) this is a sign that memory contention is happening. See discussion below on memory vs. paging vs. swapping. CPU and memory architecture: All MIPS CPUs include a primary cache. Beginning with the R4000SC, secondary cache support is usually standard. The MIPS CPU architecture really benefits from a large cache. AutoCAD is an application that benefits from a large cache. You will see a least 2X performance gain from a secondary cache. AutoCAD R13_c4 has been optimized for increase floating point performance the R4000 (or greater) CPU family. In testing, I have found: R4000PC suffers from lack of secondary cache. R4000SC runs twice as fast as R4000PC. R4600PC runs quite well without secondary cache. R4600SC runs quite well without secondary cache. R4400SC is nearly twice as fast as the R4000SC. R5000SC is faster than the R4400SC. If you are using a CPU without the benefit of a secondary cache (i.e. the R4000PC or R4600PC) you might look into upgrading your CPU to one with a secondary cache. AutoCAD is a large program and greatly benefits from the 512KB-1 MB secondary caches on the *SC CPU models; i.e R4600SC, R4400SC, and the R5000SC (the latter has an optimized GL graphics library). CPU Clock MHz (1) Primary KB (2) Secondary KB (3) ------- ------------- -------------- ---------------- R3000 (4) 20-33 64 n/a R4000PC 100 16 n/a R4000SC 100 16 1024 R4600PC 100-150 32 n/a R4600SC 100-150 32 512 R4400PC 100-150 32 n/a R4400SC 150-250 32 1024/2048 (5) R5000PC 150 64 n/a R5000SC 150-180 64 512 Table: CPU vs. Clock speed and Cache sizes Notes: (1) Typical, may not be available on all platforms. (2) Total of instruction plus data cache. (3) Typical, may vary by platform. (4) This CPU not supported with R13_c4. (5) 1M on Indy, 2M on Indigo^2. Graphics hardware: AutoCAD will run on all SGI graphics hardware. The "best" hardware to use depends on your needs, like screen resolution, color resolution, amount of graphics acceleration, etc. Screen Resolution: 1024x768 1280x1024 Color Resolution: 8-bit (with virtual 24 bit output) 24-bit true color output Graphics acceleration: Host-based graphics processor 1-8 dedicated graphics processors. The default X/Motif driver will usually exhibit similar performance on all platforms. The GL driver performance will scale with increased graphics sub-system performance. Hard disk configuration: AutoCAD can be a disk-intensive application, depending on the task. Not only is the drawing and its ancillary files (menu, fonts, XREFs, etc.) being read from and written to hard disk, but also, there are temporary files including the page file and rendering face files, in addition to the IRIX swap files. Run the program 'gr_osview -a' during an AutoCAD run and see a lot of CPU wait activity in the IO or PIO areas, this is a good indication of a disk-bound process. If you have more than one disk drive and/or more than one SCSI disk controller (i.e. Indigo^2) you might want to considering setting up AutoCAD and IRIX so that the various disk accesses occur on separate disk drives. You can control the swap file locations with the IRIX Swap Manager tool. You can control AutoCAD's page file locations via the environment variables ACADPAGEDIR, AVEPAGEDIR and AVEFACEDIR. You can control the placement of AutoCAD's other temporary files via the _CONFIG ->Configure operating parameters ->Placement of temporary files menu screen. Ideally, you should place all these various disk activities on separate disk drives for maximum performance. If you do not have enough drives to permit this, try various combinations to see what works best for you. File system performance: You could also try the new high performance XFS file system available on IRIX 5.3 and 6.2. With it you can use larger file systems (1TB or more), file sizes, block sizes and disk striping across multiple disk drives to increase disk I/O performance. Aside from the basic bigger/faster file system features, behavior in areas like directory lookup have been improved. The older EFS file system uses a linear directory format that slows dramatically as the number of entries in the file system increases. XFS on the other hand uses a tree based directory structure that maintains its performance better with larger file systems. Entries EFS XFS ------- ---- ---- 100 5970 8972 1000 1596 7089 10000 169 6716 Table: Directory entries vs. lookup operations/sec IRIX CONFIGURATION: IRIX swap file size and use: More swap space will allow larger drawings to be edited (see also: ACADMAXMEM). More swap space will not affect AutoCAD's speed. Rule of thumb: Set the swap size to 2X physical RAM size. There are several ways to change swap file size, you should use the IRIX Swap Manager (accessible from the System Manager) to change settings. Generally, swapping to a dedicated partition (raw swap) is somewhat faster than swapping to a local or NFS file. However, changing a dedicated swap partition involves re-partitioning and re-formatting a new or existing hard disk. To see what you currently have, use "swap -s": > swap -s total: 19.40m allocated + 48.80m add'l reserved = 68.20m bytes used, 135.64m bytes available On this system, I have the default 40MB swap partition on the root disk plus 64MB added in a local file system in addition to the 64MB of RAM or a total of 168MB or virtual memory. Hint: Setting up swap space, either dedicated or file system vs. using ACADMAXMEM vs. installing additional RAM can be complicated, at best. A simple way to approach the problem us to rank the techinquies according to performance vs. ease of implementation. ACADMAXMEM: (to force AutoCAD to use its internal paging mechanism) is a simple as setting an environment variable, it writes to a temporary disk file only when needed and the space is recovered afterwards. However, the performance may be slower on a fragmented hard disk. If you only work on large drawings occasionally this is a good approach. You should consider running the file system defragmenter (fsr) to ensure a disk with lots of contiguous free space. LOCAL SWAP FILE is easy to set up with the Swap Manager. The swap file size can be changed in a matter of minutes to meet changing virtual memory requirements. This is a good choice if you sometimes need to work on larger projects for a period of time. The swap performance via a local (or NFS) file system is usually faster that AutoCAD paging (because the swap file is set up in a contiguous block). However, since the swapping goes through the file system, it is not quite as fast as raw swapping to a dedicated partition. SWAP PARTITION gives the fastest swapping performance. By bypassing the IRIX file system and writing directly to the hard disk, swapping can be very efficient. If you have the luxury of a spare hard disk, an effective technique can be to dedicate that disk to swapping. Be sure it is a fast disk, though. Otherwise, you'll have to re-partition an existing disk drive to change swap file size. You'll need to backup and restore any data on that disk. In any event, you'll want to consult your system administrator unless you are comfortable with the steps involved. However, if you are setting up a new system for AutoCAD, you might choose this approach. Use the swap space rule of thumb (above) to determine a swap size based on the amount of RAM in the system (currently or planned). For example in one machine I set up, I initially started with 64MB of RAM, but anticipated that I may upgrade to 128MB in the future, so I set the swap partition to 256MB initially. MORE RAM will give you better performance that swapping to disk, but the cost is higher. You should always add RAM in the biggest increment you can afford and no smaller than the biggest bank of RAM already in the machine. If you need to replace a bank with higher density RAM, replace the one with the lowest density. Shared Memory Xserver transport: One excellent way to get increased AutoCAD performance is to take advantage of a little known feature of the X Window system, namely the Shared Memory Transport (shm). This feature is only available on local connections, that is AutoCAD running and displaying on the same machine. The feature is also a limited resource, but when used properly, gives excellent performance. Basically, shm replaces the default Xserver network-based connection (i.e. `uname -n`:0) with a shared memory buffer (shm:0). Since the memory buffer is shared between the client and server applications, no copying of data is required between them. This is a big win in interactive operations (fast turnaround time) and in applications with large amounts of data, such as redrawing million vector AutoCAD drawings. Since shm is a limited resource, you don't want to use it for everything. Rather, use it where it makes most sense, for example only for the AutoCAD Graphics window. Fortunately, AutoCAD has an easy way to do just this: setenv ACADDISPLAY shm:0 You can do this setting in ~/.cshrc or in your personal AutoCAD start-up script. I have observed about a 10% performance increase in some benchmark tests. Backing store (on/off): Backing store is a feature of the X Window System whereby a backup copy of each window is maintained, which is used to repaint the window when needed. Setting it off is best for GL driver in the Bonus Pack. Setting it on is best for Motif driver, but it can be run without it. On will consume more memory, especially over time (see also: Xserver termination, below). Certain hardware/software combinations may not support backing store. To see how its set now, use "/bin/ps -ef | grep Xsgi": > /bin/ps -ef | grep Xsgi > ... /usr/bin/X11/Xsgi -gamma 1.700000 -c -bs -pseudomap 4sight ^^^ "-bs" means backing store is off, otherwise its on. To change the setting, edit the file: /usr/lib/X11/xdm/Xservers Note: In our testing with the X/Motif driver, simply having backing store enabled results in 5-10% performance loss in AutoCAD. If any of the AutoCAD windows are further obscured a further 10% loss in performance is observed, due to the Xserver having to maintain a separate image of the obscurred window. Xserver termination on logout: Setting terminateServer to True recovers Xserver memory every logout. It is a very good idea to use this if you have backing store enabled, and won't hurt anything if you don't The time for a logout/login cycle will be a second or so longer. To change the setting, edit the file: /usr/lib/X11/xdm/xdm-config AutoCAD process priority: Normally an Irix process (like AutoCAD) is run at a default priority setting. That is, it competes equally for CPU cycles and other system resources with other processes on the system. The Irix "nice" command can be used to alter this default process priority. As a regular user, you may only lower a process priority (making the process behave "nicer"). As super-user, you may increase the process's priority. Lowering the process priority may be useful when running AutoCAD in the background, especially with the "AutoScript" command feature, or when running multiple AutoCAD sessions on a given machine (in conjunction with the ACADMAXMEM setting). Kernel Tuning Parameters Please consult the IRIX Administration Guide: System Configuration and Operation section (Appendix A) for a complete description of IRIX kernel tuning parameters. Below are extracted, for your convenience, several parameters that can affect AutoCAD operation under IRIX. bdflushr - specifies how often the dirty file system buffers are flushed Description of bdflushr The bdflushr parameter specifies how often, in seconds, the bdflush daemon is executed; bdflush performs periodic flushes of dirty file system buffers. Value of bdflushr Default: 5 Range: 1-31536000 When to Change bdflushr This value is adequate for most systems. Increasing this parameter increases the chance that more data could be lost if the system crashes. Decreasing this parameter increases system overhead. Operations, such as loading an assembly or drawing, cause significant I/O waits. Sometimes increasing this value to 60 or 120 seconds can help reduce this bottleneck. nbuf - number of buffer headers in the file system buffer cache Description of nbuf The nbuf parameter specifies the number of buffer headers in the file system buffer cache. The actual memory associated with each buffer header is dynamically allocated as needed and can be of varying size, currently 1 to 128 blocks (512 to 64KB). The system uses the file system buffer cache to optimize file system I/O requests. The buffer memory caches blocks from the disk, and the blocks that are used frequently stay in the cache. This helps avoid excess disk activity. Buffers are used only as transaction headers. When the input or output operation has finished, the buffer is detached from the memory it mapped and the buffer header becomes available for other uses. Because of this, a small number of buffer headers is sufficient for most systems. If nbuf is set to 0, the system automatically configures nbuf for average systems. There is little overhead in making it larger for non-average systems. Value of nbuf Default: 0 (Automatic if set to 0) Formula: 100 + (total number of pages of memory/40) Range: up to 6000 When to Change nbuf The automatic configuration is adequate for average systems. If you see dropping `cache hit' rates in sar(1M) and osview(1M) output, increase this parameter. Also, if you have directories with a great number of files (over 1000), you may wish to raise this parameter. Less than 85% on the %wcache and/or less than 60% on the %rcache indicates that the system is I/O bound. dwcluster - (EFS) number of delayed-write pages to cluster in each push. Description of dwcluster This parameter sets the maximum number of delayed-write pages to cluster in each push. Value of dwcluster Default: 64 When to Change It should not be necessary to change this parameter. The automatically configured value is sufficient. autoup - (EFS) specifies the age, in seconds, that a buffer marked for delayed write must be before the bdflush daemon writes it to disk. Description of autoup The autoup parameter specifies the age, in seconds, that a buffer marked for delayed write must be before the bdflush daemon writes it to disk. This parameter is specified in /var/sysgen/mtune. For more information, see the entry for the bdflushr kernel parameter. Value of autoup Default: 10 Range: 1-30 When to Change This value is adequate for most systems. semmni - Maximum number of semaphore identifiers in the kernel. Description of semmni The semmni parameter specifies the maximum number of semaphore identifiers in the kernel. This is the number of unique semaphore sets that can be active at any given time. Semaphores are created in sets; there may be more than one semaphore per set. This parameter is specified in /var/sysgen/mtune/sem. Value of semmni Default: 10 When to Change semmni Increase this parameter if processes require more semaphore sets. Increasing this parameter to a large value requires more memory to keep track of semaphore sets. If you modify this parameter, you may need to modify other related parameters. Note: 1. AutoCAD and ADS: AutoCAD uses semaphores for interprocess communication with ADS applications including ASE. To get an idea how many semaphores you need load one AutoCAD+ADS session and run the command 'ipcs' and note the results. Now load a second session and re-run 'ipcs'. The change will tell you how many semaphores are used per session. You may want to do this after rebooting to ensure you have no 'lost' semaphores. 2. AutoCAD and ASE: You may sometimes experience 'lost' semaphores and/or shared memory message queues with ASE due to improperly disconnected SQL sessions. If you are experiencing these kinds of problems, you can use the 'ipcrm' command to 'clean-up' the 'lost' resources but you should also correct the situation causing the problem. This most frequently occurs when initially trying to establish connections to Oracle and Informix database servers and having improper user names and passwords. Once the proper connection method has been established, this problem should not re-occur. Setting Tunable Parameters The directory, /var/sysgen/mtune, contains the files defining tunable parameters that are typically tuned with the systune command. An example of changing a parameter is shown below. Updates will be made to running system and /unix.install # systune -i systune-> nbuf nbuf = 509 (0x1fd) systune-> nbuf 1600 nbuf = 509 (0x1fd) Do you really want to change nbuf to 1600 (0x640)? (y/n) y In order for the change in parameter nbuf to become effective, reboot the system systune-> quit # autoconfig -v # reboot An alternative method of setting parameters is to edit the file /var/sysgen/stune (as root) and add lines for each tunable parameter you wish to change. With this method, you can preserve the original system settings (in /var/sysgen/mtune/*) and keep your changes confined to the local stune file. After editing the file, run: # autoconfig -v # reboot as described above. AutoCAD Settings: AutoCAD's memory pager (controlled with ACADMAXMEM): AutoCAD, by default will use all available (physical+swap) memory space, competing with other programs for resources. Using the default setting may cause the workstation to run slower, as parts of AutoCAD, the driver, or the O/S get swapped to disk. Setting ACADMAXMEM in the 10-16MB range on systems with 32MB or less is a good staring point. A value about 1/2 the physical RAM is a good starting point. If you have additional memory, increase this setting appropriately. If running multiple copies of AutoCAD, reducing ACADMAXMEM is crucial. AutoCAD's memory pager is quite intelligent and efficient. VIEWRES setting: This AutoCAD setting controls the number of vectors used to display circles, text, etc. Using too large a value can inflate memory use, especially in 32-bit display list mode. Try to use a value in the 100-1000 range for most purposes. Values way less than 100 are even better (performance-wise). Set it as low as possible without affecting your drawing accuracy. SPLINESEGS setting: This AutoCAD setting controls the number of line segments that make up a spline curve. Using too large a value can inflate memory use, especially in 32-bit display list mode. The default value is 8, but lower values are fine. Set it as low as possible without affecting your drawing accuracy. MAXACTVP setting: This setting controls the maximum number of active viewports allowed in AutoCAD. By default is can be up to 64, determined by the display driver's capabilities. If you only use a few viewports, you can reduce this value to a smaller number to reduce memory and CPU overhead. DRAGMODE setting: This controls whether objects being dragged are displayed. If the object is complex, this can make the dragging operation much more interactive. The GL display driver also has an option to try to cache or not cache dragged objects. Caching is useful when the object is complex and not changing from frame to frame, such as in a _MOVE or _COPY command. If however, you use a _ROTATE or _SCALE command, the object must be erased and redrawn differently each frame. For this operation, the caching-off version is best. These controls are accessable in the Configure->DriverOptions dialog. ISAVEPERCENT setting (some AutoCAD versions): This setting controls the incremental saving of drawings. Seeting this to 50(%) can speed drawing saves. With R13_c3, this value must be left a 0 to avoid a potential problem. ISOLINES setting: Specifies the number of isolines per surface on objects. Valid integer values are from 0 to 2047 and the default value is 4. Setting this to 0 results in only no additional iso-lines being created. FACETRES setting: This setting controls the "smoothness" of rendered solid objects. Values can range from 0.01 to 10.00. The default is 0.50. Smaller values result in coarser surface meshes and therefore smaller display lists and for exporting to Inventor and VRML, smaller files as well. You should set this value to the smallest that produces adequate results. One place you may consider using a higher value is in the production of multiple Level Of Detail (LOD) versions of your model for VRML worlds. For example, creating a complex, smooth version for close viewing, a less complex/detailed version for middle distance viewing and a very simple/coarse version for distant viewing. You can then import and combine these three LODs into CosmoWorlds in the LOD editor. SCROLL Lines setting: AutoCAD on Unix offers the ability to maintain a scollable text screen and command prompt area. Several X resource settings control this feature. These are: AutoCAD-Graph.scrollLines: mmm AutoCAD-Text.scrollLines: nnn These settings control the number of lines of text to be maintained in the back-scroll buffer for the command prompt area of the graphics window and the text window respectively. By default they assume rather large values (from 100's to 1000's of lines). If your AutoCAD application or test produces any quantity of text output, you may find the back scroll buffer may impact performance. Therefore, especially if you don't find this feature of value, you should consider reducing the size of the backscroll buffer down to a minimum of the size of the window. After all this is the situation you get on a DOS machine, e.g. in a 25 line text screen, the last 25 lines of text output are "remembered". 3DFACES (with AVE Render - R12 only): Render is part of the Autodesk Visualization Extension. One of its features is the ability to pass 3D data directly from AutoCAD to the GL display driver. Doing so bypasses all the complicated processing normally needed to display rendered images. The 3DFACES command enables the 3D display list capabilities. On drawings of 10,000 faces, 3D rendering can be more than 10 times faster than 2D rendering. This allows use of the hardware Z buffer, and graphics accelerator for better image quality. Allows the 3D display list to be replayed in the same viewport any number of times without regeneration. Hint: See the Inventor file export feature (below). Hidden line removal: In R12 this process is optimized for 32-bit CPUs and runs 10-100X faster than R11 style hidden line removal. If at all possible, don't use the "R11-style" hidden line algorithm, as it is not optimized. The GL Driver also offers a hardware accelerated hidden line viewing mode that is 10-100X faster, again, (see 3DFACES). GL Driver/Bonus Pack Settings: The GL driver is the primary component of the Bonus Pack software. It gives you all the features of the default (Motif) AutoCAD display driver but also provides many enhanced features. This is primarily done through providing direct access the GL graphics engine that is in every SGI workstation. It is a full-featured AutoCAD driver and has a number of user-configurable options: Display list coordinate size (16/32 bits): 32 bit mode is better for REGEN-intensive tests. Uses at least twice the memory of 16-bit mode. Allows you to zoom in to your drawing without causing a REGEN. 16 bit mode has better memory use and faster drawing. It is about 5% slower in REGEN's, but 10% faster in REDRAW's. Refresh Display list (on/off): The refresh display list management can lead to excessive memory use during editing and automated scripts. Enabling the GL driver's Refresh Display list mode helps refresh the graphics screen after window exposures; e.g. popping the graphics window. However, it comes at a price, both in extra memory for the refresh display list as well as extra time in redrawing the refresh display list. Imagine a 1M vector drawing in which you select all vectors for a subsequent operation. AutoCAD wants to highlight each selected vector, these are normally non-drawing vectors, but in refresh mode, the driver saves them to use in case the screen needs refreshing. After the selection set is complete, AutoCAD dehighlights all the vectors with more non-drawing vectors. As a result, you end up with a 1M vector drawing display list and a 2M vector refresh display list. The idea for turning refresh mode off is that once you've selected some geometry (for example via a dialog box), you'll probably change whatever has been selected upon dismissing the dialog. Rather than going through the effort of 'repairing' the window damage under the dialog just to throw it away and draw the results of your change, why not just ignore the non-drawing stuff and proceed as if nothing happened. If you rarely restack windows or can tolerate some minor window damage (i.e. missing UCS icons, etc.) and want more interactive speed, turn refresh off. A REDRAWALL or CLEAN command will always clean up the screen for you if needed. If you do a lot of window restacking and demand accurate graphics display turn refresh on or use the X/Motif driver with backing store enabled. Note that refresh mode is still not perfect. Most benchmarks will run faster with refresh off. Display list cleaning (on/off): AutoCAD's display list management can lead to extra memory use during editing and automated scripts. Enabling the GL driver's RT Clean mode helps reclaim memory during automated tests. This is good while running AME and ADS applications. Turning RT Clean off is faster during manual, interactive operations like moving, copying and block insertions. Most benchmarks will run faster with Cleaning off. Display list page size (4K-256K): Larger pages are more efficient in terms of speed (to a point, 32KB is a good size). Smaller pages use less memory, especially with many viewports and are also more efficient when display list cleaning is enabled. Screen mode (Default/single/dual): AutoCAD runs with two windows, but it is possible to configure the behavior of these windows to suite your needs. The default mode is user-friendly, but causes un-necessary overhead. Single screen mode is best used when running command scripts. The text screen is not kept updated, so it is much faster. Often 2/3 of a test's time may be consumed with text display. Dual screen mode is a good compromise between the above two modes, the text screen is updated, but the overhead is less. Polygon Outlining (on/off): By default, the IrisGL interprets polygons as the set of pixels contained inside the polygon border. This provides good performance and visual results for rendered scenes composed of polygon meshes that cover the surface. However, AutoCAD also uses polygons to represent PLINES (to allow for line width). As such, these polygons may not actually fill the scene and if the zoom ratio of the current view is just right, there may be no screen pixels contained within the polygon and the PLINE will "disappear". To avoid the visual affects of this behavior, the GL driver allows an explicit polygon outline mode, where the polygon border is retraced as a line to guarantee its being visible, regardless of view. This features comes at a price of about a 50% speed penalty in REDRAWs. If you need this mode enabled, by all means turn it on, but if your style of drawing does not need this feature, turn it off (the default setting) for increased speed. The SGI_OUTLINEn command controls this setting. SGI_OUTLINE0 is off SGI_OUTLINE1 is on (default) Entity Highlighting (on/off): According to the ADI specification, selected entities are to be drawn once with the entity color with a highlighting pattern (e.g. "- - - - ") then again in the background color with an alternate pattern (e.g. " - - - -"). The advantage of this technique is that you can more easily determine the selected entity, for example assume you draw a red line over a green (existing) line. A selection would probably hit the green line (as it is 'first') and it would appear on top and highlighted. However its drawback is that lines must be drawn twice (with a line pattern change in between each line). An alternative approach (SGI_HILITE0) is to only draw the background pattern over the line for a highlight. This cuts the drawing requirements in half and allows the line pattern to stay constant. Also, in practice, if you have two red line on top of each other, the color alone is not sufficient to tell one from the other. SGI_HILITE0 is off (simple highlight) SGI_HILITE1 is on (default) Motif or GL user interface: Using the GL user interface components is faster and uses less memory. You give up the iconic pull-down menu capability. You still get Motif dialog box support. You may want to retain the Motif status line and toolbar features. Do this by setting the AutoCAD-Graph*use... items to FALSE in .Xdefaults. Window size: Using a smaller window can produce faster redraw speed and reduce memory use. Iconifying the graphics window can also speed automated operations and free screen real estate for other uses. The NULL display driver is quite efficient for doing background tasks, and is used by the AutoScript feature. Check out the shell script file named 'autoscript' in your AutoCAD executable directory. Finally the GL driver allows has several features to replace the NULL display with some added benefits. The NULL display does not support the rendering interface and can therefore not handle operations requiring rendering (like 3DSOUT). Also, the GL driver is better optimized for IRIX and runs faster than the NULL display driver. To enable the Autodesk NULL display: setenv ACADDISPLAY NULL To disable the Autodesk NULL display: unsetenv ACADDISPLAY To enable the GL NULL display mode: setenv ACADDISPLAY . setenv ACADTEXTDISPLAY . To enable the normal GL NULL display mode: unsetenv ACADDISPLAY unsetenv ACADTEXTDISPLAY To free up screen real estate with the GL driver, you can also re-direct the text screen to an alternate display screen via the ACADTEXTDISPLAY variable. Setting ACADTEXTDISPLAY to a valid X display will send it to that display; e.g.: setenv ACADTEXTDISPLAY host:0 Setting it to a TTY port will send output to a text port or serial terminal connected to the system. See a further discussion of this feature in the GL driver release notes. Integration with the operating system: The Bonus Pack provides full integration of AutoCAD into the Indigo Magic environment. Among the supported features are Drag&Drop, file type definitions, automated AutoCAD command script handling. These features allow you to to work more productively. Printing and Plotting: Impressario gives fast network printing capabilities. Your host processor functions as a PostScript raster image processor, driving the printer at its maximum speed. The Bonus Pack includes built-in support for Impressario printing. Inventor/VRML file export: Inventor is a 3D visualization environment standard on all SGI machines. It allows you to view, manipulate and share your AutoCAD drawings with other users who may not have access to AutoCAD or know how to use it. This is also the gateway into collaborative design allowing you to incorporate AutoCAD drawings into presentations, electronic mail and even with live interactive conferences with others. This is also a handy technique to use to preview parts libraries and designs in progress. Rather than the time consuming HIDE, SHADE or RENDER process in AutoCAD, simply export the model in Inventor and have it ready to view at a moments notice. BOTTOM LINE: The bottom line to tuning AutoCAD is to realize there are many factors influencing performance on a Unix workstation. If you make a systematic and well-planned search through some of the adjustments, you'll probably find settings that produce optimal performance for your typical tasks. FEEDBACK: If you find any other factors that affect performance of AutoCAD and would like to share that information, please send me via: INTERNET: mailto:r.c.brown@ieee.org WWW: http://reality.sgi.com/autocad/