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NX 7.5 Slow Model Rebuild

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XZ06RM

Automotive
Dec 15, 2011
6
My 7.5 NX model dataset is about 33MB in size. I have about 1,100 features. The model is a chunky solid.

Ever since last week my model is extremly slow to update. To rebuild from featue 1 to 1,100 takes at least 10 minutes. I'm on Teamcenter 8.3.

I exported the model to a new file thinking that would help. No change.
I ran part cleanup. No change.
I loaded up a baseline from several weeks ago...that is slow too.

My computer is a HP Elitebook notebook with 16GB RAM
Processor Intel Core i7 Q840
Graphics: nVidia Quadro w/ CUDA (?)

Any ideas or suggestions on what I might do to get some performance back? I think they rolled out some update around the time my slowness started.

Thanks!
 
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I often rebuild a model from scrath (If I have the time) and combine/simplfy/eliminate unnecessary features I've rarely found the need for more than 500 features in a fully parametic single part file. When you get into the higher feature counts like you describe a slowdown is inevitable.
 
Last week the model was OK though. This model is already pretty much optimized for feature count. Maybe I could reduce it by about 100 but it would be a lot less editable then.
 
Are there any settings in NX that will effect how quickly a model rebuilds?
 
Can you have someone else open it up and rebuild features to see maybe if it is your workstation? or part related?

John Lackowski
NX Support
Win 7 64bit NX 7.5.4.4 TC 8.3.1.1
 
Check your features/mark setting (Preferences -> Modeling -> Update (tab)). The default setting is 1 feature/mark, but the rule of thumb is ~10% of the number of features in your file (in your case I would try setting it around 100). John Baker gives a better explanation of this in thread561-277994.

XZ06RM said:
I think they rolled out some update around the time my slowness started.
Of course if the slowness is due to an update, the above suggestion won't work. Do you know what type of update this was (NX patch, windows update, etc)?
 
If we're talking about models which are still under development and will likely be changed several times before being 'frozen' and released to production, you amy wish to go to...

File -> Options -> Save Options...

...and toggle ON the 'Save Date for Fast Rollback and Edit' option. This will help to improve that first time (after opening your part file) update of your model after an edit. The reason that I say this may be a consideration IF the model is not yet ready for 'release to production' is that this will cause the saved part file to be significantly larger, which may be fine while a part is still a 'work-in-progress', but which would waste file space if parts were archive with this option ON.

Another setting that can have an effect on update performance is the 'Features/Mark' setting in the...

Preferences -> Modeling -> Update

...dialog. Now as to what to set it at, for that absolute biggest impact you would set this option to 1, however that will require more memory and will also cause your part files to require even more disk space if you've also set that option I discussed on the previous part of this post. Generally speaking, if you are working with large models (in terms of the number of features) at setting of 10 will probably give you just a much of a benefit, but you could try 5 as a compromise.

Now there is one more issue which is sometime a bit controversial and that's what have you set as your modeling tolerance to. Out-of-the-box, the modeling tolerance has been set for what is considered to be a good nominal value for most of our customers, 0.001 inches for Imperial Unit parts and 0.0254 mm in Metric Unit parts. The only time I would AUTOMATICALLY consider making an across the board change to this setting (in Customer Defaults) would be if if designing and manufacturing very small or very large products, perhaps something like watches at one end and locomotives at the other end of the spectrum (although now that we're selling to more ship builders, perhaps something like a submarine or an aircraft carrier might be better examples of where the upper limit is). If you're somewhere in between these examples, I would stick to the above quoted values.

Now one thing to remember is that not all modeling operations are effected by this tolerance setting but those which are generally include in the dialog a parameter entry where you can override the default tolerance. In those cases this tolerance will be included as a parameter of that feature and which can be edited later on. It also means that once a feature has been created, going back and change the default tolerance, either in Customer Defaults or under Modeling Preferences, this will have NO effect whatsoever on any existing feature.

So our advice, unless you really are working at or near one of the extremes I sited above, you should leave the defaults alone and only if while creating a feature that you feel that a difference tolerance would be more appropriate then make that change for THAT feature only, don't bump up the global tolerance.

Now the reason that this can have an impact on performance is that if your model contains complex faces, either created as B-surfaces or as the result of complex swept or blend features, have too small a tolerance can cause the geometry being created (edges and faces) to be more complex than it needs to be (more data points being needed to define the shape), which will BOTH increase the size of your model in terms of the memory needed to save it and work on it during an NX session. Also this will slow the update as more data needs to be evaluated when the feature updates and the resulting geometry may require additional time and memory in order to be properly rendered, particularly when computing mass properties and things like Hidden-Lines.

Anyway, these are a few things that you may wish to review which could have an impact on model update time.

Also note that there are some things which are not directly related to model update time, but could still give you the feeling that overall performance is poor and that could include display tolerance settings, system memory, graphics cards, disk access speed, etc.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.
 
Tried it on another machine...still slow.

Exported my data to a local file on the desktop and ran UG Native. Still slow.

One weird thing...I will be on feature, like 1000. Go to change current feature to 1100 and it will start rebuilding at around feature 600.

Thoughts?

 
Please read the comments about 'Features/Mark' in the previous posts as well as the option to save rollback data for your next session.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.
 
Sorry, yeah I tried those with the 100 setting (it was 1 before). It's still about the same. I will have to pull a baseline from a month ago or so to make sure the older file versions are running slow too.
 
I still have not resolved the OP issue. I tried other models on my system and they seem to run faster so I'm thinking there must be something in the model that is causing it to slow down. Any idea how I would trouble shoot the model to find the offending feature(s)?

Here's a list of some benchmarks on different iterations of the model I did:

img
 
Try running Analysis -> Examine Geometry on the part geometry, pay special attention to the 'body checks' and 'face checks' sections. Sometimes NX can repair or ignore errors as you go, so if you have an error early in your file it may take longer to rebuild.
 
When a model is updating the system displays the feature names in the status bar as the update runs. If you watch carefully you should be able to notice the time it takes to update various features by how long their name remains shown on the status bar. If you see where a feature's name seems to remain shown for what feels like a long time, this might help indicate where you need to start looking for problems. The best tool for narrowing in on exactly where the problem might be would be use the Model Playback tools. Now you could just go to...

Edit -> Feature -> Playback...

...and using the 'VCR-style' controls you can run the entire model, manually updating one feature at a time, from the start of the model. However, if your model is large it's better to first turn on the 'Feature Replay' toolbar and then select a feature a few places BEFORE where you think you may have a problem, press MB3 and select 'Make Current Feature'. This will roll the model back to where only the features to that point have been created. Now using the 'VCR-style' controls on the Feature Replay toolbar you can 'jog' the model forward and backward one feature at a time starting where you model is currently at in it's update 'history'. As you move forward you will be able to tell exactly how long it takes for each feature to update.

Anyway, give that a shot as this will help you narrow down where it is that may need to look to find the problem.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
UG/NX Museum:
To an Engineer, the glass is twice as big as it needs to be.
 
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