Handling BIG assemblies 2

[AnthonyK]

Hello guys,

This is my first post here, so, please, do not be harsh with your comments.
Question: will workstation with configuration given below be capable of working with assemblies of 30000-60000 elements (nothing complicated, very few patterns)? If not, where could be the bottleneck?

CPU: Core 2 Duo E6850;
RAM: Corsair 8GB (4x2GB) DDR2-800;
VIDEO: Quadro 3500;
HDD: WD Raptor 10k rpm SATA;
Motherboard: Intel Dragontail Peak DP35DP;
Nothing is overclocked.
Why asking: soon we will have to work with assemblies of size given above and thinking of new workstations with best Price/Performance ratio.

Hope everything is clear and enough info is given.
Thanks in advance,

Antons Kuzmins
IT system analyst + SW administrator
AS Sidrabe
Latvia

 

[EEnd]

That looks like a good base for some fairly high end systems. With what you are investing in the rest of it, you may want to consider a raid array with the hard drives. You will also need a 64-bit OS to take advantage of the 8GB of RAM. SolidWorks is not currently supported on 64-bit Vista so you will need XP 64.

I have no experience with assemblies with 30,000 to 60,000 components, but I expect that they will be challenging. I think success when working with assemblies of that magnitude depends as much or more on design practice than on hardware specs. Careful use of subassemblies and the creation of simplified configurations of parts and subassemblies allow the level of detail to be tailored to maintain responsiveness within SolidWorks. This works best if the structure of the assembly within the SolidWorks is planned or designed with the ability to tailor the level of detail.

Eric

 

[AnthonyK]

Hi Eric

About the OS - yes, forgot to mention that. We indeed are planning to install Win XP Pro 64bit. And I understand, that this configuration is almost maximum we can get from non-Xeon systems. And we thought about raid but decided to go with one HDD to system and one for SW for security of information.

But question remains: if anyone have/is worked/ing with assemblis this big, what hardware he was/is using?

Antons

 

[ctopher]

SolidWorks.com has specs needed for hardware. Depending on your hardware, settings, configurations and user knowledge, you can that many parts without problems.

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 10-07-07)
ctopher's blog

 

[StefanHamminga]

This system looks pretty decent, very similar to my systems. Only point would be the amount of graphics ram, the 3500 has only 256 MB... then again, I had no problem with 20k part assemblies. Why do you think using 2 drives seperate is safer than raid 1? I would think raid 1 is far more reliable.

Stefan Hamminga
EngIT Solutions
CSWP/Mechanical designer
Searching Eng-Tips forums

 

[pierdesign]

Hi AnthonyK, this is my first post here too, so, please, do not be harsh with your comments.

I have made numerous assemblies with 10 ~ 50,0000 parts and my system is nowhere near your's. I found several things helpful in part creation to allow working with these large assemblies:

All parts have same coordinate system so the assembly has no mates. The part models should be very clean with minimal cascading parent-child relationships. Don't edit parts with assembly open. Assembly patterns seem faster than multiple incidences.

 

[CorBlimeyLimey]

"All parts have same coordinate system so the assembly has no mates."
So your assemblies are not associative? Do you just Fix everything?

 

[dgowans]

All parts have same coordinate system so the assembly has no mates.

I would interpret that statement to mean that everything is modeled in place. This is a common practice in automotive product design (or at least it was when I was in automotive). You could choose to fix everything, or not. In some CAD systems that wouldn't be necessary; in SWX, I'd fix all components.

 

[AnthonyK]

To Stefan:

Well, RAID1 is more reliable than simply 2 drives, but in that case I lose some HDD speed. So, in my opinion, I have chosen compromise between reliability and performance. Correct me if I am wrong. Would You better recommend 1700FX or 4500FX?

To All:

Thanks for Your input on this problem. So far the main idea is that with assemblies this big hardware is not the main slowdown, but the way assembly is built is, right?

Antons

 

[Updraft]

Antons,

How you build the parts and assemblies will have a HUGE impact on performance.

Parts: Don't over-detail a part, only use as much detail as necessary. For instance use a hex head and cylinder for bolts with only a cosmetic thread. It is rare that a true helical thread or even a linear pattern of V-grooves is necessary. For other parts where you need the detail for the part drawings, but not the same level of detail for the assembly consider using two configurations of the part: Detailed (part drawing) and Simplified (for assemblies).

Assemblies: 1. Use subassemblies out the ying-yang! This dramatically speeds up building the intermediate and top-level assemblies. I even use subassemblies (with configurations) containing a bolt, washer(s) and nut. Look for areas where there is repetition and make those parts into a subassembly. 2. Patterns - Patterning holes is perhaps the best application that is too often overlooked. I make the seed hole a different color so it is easy to spot in the (sub)assembly, mate the bolt-washer-nut-bracket (or whatever the part or subassembly is) to this seed hole and then "insert component pattern" to follow the pattern made from the seed hole. This is a dramatic time saver for building assemblies.

Using subassemblies and patterns typically yields much faster regeneration than if everything were an individual part and mated. This is because there are actually fewer and simpler calculations for the software to perform.

When I was in the aircraft industry we too used global coordinates for everything so every part came in to the assembly mated to the global coordinate frame. While this has some merit it carries with it a huge problem - parts aren't actually mated to each other, they are instead in close proximity to each other. Besides, this only worked for unique parts; parts used in multiple locations couldn't have multiple global coordinate frames. I don't know what the aircraft industry does now (it's been 14 years), but we ONLY mate parts to each other in the work I've done since. We catch so many "Gotcha's!" this way.

By the way, you can create subassemblies while in the top level assembly (such a handy tool!) and you can dissolve subassemblies into the top level assembly.

For assemblies to regenerate as fast as possible and to build in the first place use as simple geometry as possible for the parts and use subassemblies and patterns liberally. Oh, and of course use lightweight assemblies.

Sorry for the length of the post but I got to sleep in this morning so I am re-energized!

- - -Updraft

 

[AnthonyK]

Thanks Updraft for concentrated tips on assemblies and parts. Star for You.

 

[CorBlimeyLimey]

SW has a 300 mate limit for assys. If that limit is exceeded, performance takes a big hit. Sometimes to the point of crashing. A way around that limit is to Fix the components after the mates have been applied. This will suppress the mates so they aren't evaluated when the assy is rebuilt.

 

[AnnaWood]

I really think the 300 mate limit concept is a old wive's tale. I have asemblies with more mates then that that work just fine.

The biggest key to performance is how you structure your model through the entire process. From sketches to mates (soup to nuts).

FWIW.....



Anna Wood
SW 2007 SP4.0, WinXP
Dell Precision 380, Pentium D940, 4 Gigs RAM, FX3450

http://designsmarter.typepad.com/solidmuse

http://www.phxswug.com

 

[CorBlimeyLimey]

I don't know the source of the 300 mate limit or when it first surfaced, but when past threads here have reported assembly performance problems the limit had usually been exceeded and reworking the assemblies to reduce the TL mates apparently alleviated the problem.

For sure, good model creation techniques and assembly practices can only serve to improve performance.

Not mate limit related but maybe helpful nonetheless;

http://solidworks.com/swexpress/pages/cadalyst_archive/CAD_AssemblyTips.html

 

[brengine]

Will any of your files be imported? In particular imported from Catia? It only takes one of these files (that is really complicated, and may or may not have converted to SW without errors) to bring SW to it's knees.

Ken

 

[AnthonyK]

Thanks CBL, for tip about fix trick to supress mates, I did not know that. Star from me.
To Ken: no imported parts in the asembly,but thanks for a tip, now I'll be aware of this.