What are you doing in Inventor when it runs a single core at full speed? That often happens to me and it's not necessarily an indicator of a problem.
As was mentioned already, Inventor is generally a single threaded application with a few exceptions. To borrow from the car world, there's no substitution for Gigahertz! I'm partial to the E5-1650 myself. It starts at 3.2 GHz but can turbo boost to 3.8 GHz; a bit better than the 2643's max 3.5 GHz. Plus it's a 6-core, which helps if you have multithreaded apps. It's also cheaper than a E5-2643.
If you feel that your system is slower than it should be, here's some ideas...
-Check that your hard drive is plugged into the fastest SATA port available. I've recently found some 6 Gbit 10K RPM drives plugged into the 3 Gbit port on the motherboards. Although, it probably won't make any appreciable difference in overall performance.
-See what speed RAM shipped. That CPU is capable of using DDR3-1600. Sometimes vendors install slower ram and that can be a huge bottleneck during intensive CPU activity.
-The CPU is also capable of quad channel ram configuration. That means the best performance is achieved by installing ram modules in groups of four in the same color ram sockets. Not doing this can reduce performance, but not as much as using slower clock speed ram.
Some reference material...
Just seen the effects again. An Inventor IDW of a 33,000 part assembly: HT = on, drawing opened in 6.5 minutes. HT = off, drawing opens in about 2 minutes.
I would love to know why HT makes such a difference if anyone has any facts? (Opinion is OK as long as it is substantiated!)
I'm assuming this is repeatable both ways, so you aren't dealing with data being cached or similar effects?
Hyperthreading deals with "virtual" cores rather than physical ones, and gets handled with code rather than hardware. If the calling software isn't optimized for multi-threading then you could be dealing with the overhead of spooling up and reconciling not only different threads between cores but between the virtual cores as well. With hyperthreading turned off, any miscellaneous threads are being forced to a different physical core rather than sharing a virtual one.
Ah, for the days with an 8088 and an LED probe...
No caching. The advantage of testing HT on/off is that it's changed in BIOS which forces a reboot between tests.
The tests were on the same drawing and followed exactly the same procedure, so repeatable... Yep.
The actual numbers were 6.5 minutes with HT on, and 2.5 minutes with HT off. 4 minutes saved per file, per number of open's, per user, per day... Adds up really fast! Just going to do some more testing on view-creation and update times.
I conducted an experiment this morning. I'd like to do more testing with different scenarios, but I have to do SOME real work, too.
Update all sheets: 16s
Update all sheets: 27s
Update all sheets: 15s
Update all sheets: 28s
These were both multi-sheet drawings with about 65-80 sheets of an assembly and details with around 1000-1500 instances of 120-160 unique parts. Note that we have approx. 30% faster opening times with HT off, but no appreciable change to the update time.
I'm going to work with HT off for a while and try to get a seat-of-the-pants feel until I can get around to doing more testing.