topic Inventor performance affected by cpu speed stepping? in Inventor Forum

Inventor performance affected by cpu speed stepping?

pball — Fri, 02 Jun 2017 23:06:48 GMT

I decided to retest my personal computer with the Inventor Benchmark program to compare it with the new 7700k computer at work I'm setting up. While doing so I noticed something funny. Skipping the back story I found out that I get a significantly lower score when my computer is in "Balanced" power mode which adjusts the cpu clock speed depending on the load. Changing to the "High Performance" power mode which keeps the cpu clock speed at the maximum, the scores are higher.

I'll be running the same test on the new work pc to see if different hardware has the same kind of result.

I ran four 3 cycle tests in a row, two tests in each power mode and alternating modes between tests.

My specs:

i7 5820k overclocked to 4.3ghz

32gb ram

250gb 840 Evo SSD

9.83, 9.76 high performance mode

6.71, 6.62 balanced mode

test1

test 2

test3

test 4

I know the benchmark program isn't the end all but these results are consistent and different enough that I wanted to share this.

Re: Inventor performance affected by cpu speed stepping?

blair — Fri, 02 Jun 2017 23:58:08 GMT

CPU clock speed is critical for the performance of Inventor. Since it only utilized a single core for modeling, the higher/faster the clock speed will produce better results. Nothing unusual with those results, since it's CPU speed dependant.

Re: Inventor performance affected by cpu speed stepping?

pball — Sat, 03 Jun 2017 01:58:53 GMT

blair it sounds like you might be misinterpreting what I'm saying. The max clock speed is not being changed during these tests. The cpu can and does run at 4.3ghz in all tests. The difference is the built in power savings feature that automatically under clocks the cpu when there is less load and returns the clock speed to normal under higher loads. I am fully aware of how Inventor performance is closely tied to single core clock speed and this post is about not about comparing different clock speeds.

To elaborate, when the balanced power mode is on the cpu clock speed varies depending on the load. So for example during the times Inventor closes between some of the tests the cpu will down clock to 1.0ghz or so and then when the next test starts up again the clock speed will go up again. I have seen programs which do not function well when this dynamic cpu speed feature is enabled and the performance will be lessened.

Re: Inventor performance affected by cpu speed stepping?

blair — Sat, 03 Jun 2017 06:30:20 GMT

My systems are always set to Performance. The Balanced Power setting is always trying to throttle back the CPU clock speed. Since IV only uses a single core for modeling, allowing the other cores to idle. The overall affect for the power management is to throttle back.

Since all our workstations have an external UPS, Windows thinks they are laptops and wants to employ the "Balanced" setting as the default. I'm pretty sure it started with SP2 for Windows XP.

Another setting, on laptops with conventional Hard-Drives can be found in the system BIOS setting. Dell is famous for having a "Quiet" Hard-Drive setting which slows down the Read-Write heads for quieter operation.