Low optimisation speed

Use this forum to post Vensim related questions.
Post Reply
Simplifier
Senior Member
Posts: 51
Joined: Tue Sep 11, 2018 2:04 am
Vensim version: PRO

Low optimisation speed

Post by Simplifier »

Since my model was being optimised really slowly on my MacBook air (Macintosh with CPU Core i5 1.6Ghz , and 4 GB Ram), for example each simulation run would take at least 5 secs, I purchased a very powerful PC (Windows with CPU AMD Ryzen 7 (3700X) 8 core, and 32 GB Ram) so I could accelerate the optimisation process. I have run the same model with the same features on this new powerful PC, but each simulation run takes about 7 secs.

It has extremely disappointed me as I have paid a lot of money for the new PC and I still do not know why it's running faster on my low performance Macbook Air than the powerful PC. Is it because of the Windows operation system on which the Venism is running slower??

tomfid
Administrator
Posts: 2937
Joined: Wed May 24, 2006 4:54 am

Re: Low optimisation speed

Post by tomfid »

There shouldn't be much difference from the OS. Any chance you were running compiled on the Mac?

Simplifier
Senior Member
Posts: 51
Joined: Tue Sep 11, 2018 2:04 am
Vensim version: PRO

Re: Low optimisation speed

Post by Simplifier »

tomfid wrote:
Fri Mar 27, 2020 3:56 am
There shouldn't be much difference from the OS. Any chance you were running compiled on the Mac?
I dont exactly know what compiling means in this particular situation, but I am doing the same process, borrowing the different required files from their sources individually.

Simplifier
Senior Member
Posts: 51
Joined: Tue Sep 11, 2018 2:04 am
Vensim version: PRO

Re: Low optimisation speed

Post by Simplifier »

tomfid wrote:
Fri Mar 27, 2020 3:56 am
There shouldn't be much difference from the OS. Any chance you were running compiled on the Mac?
Any other recommendation Tom?

Administrator
Super Administrator
Posts: 3522
Joined: Wed Mar 05, 2003 3:10 am

Re: Low optimisation speed

Post by Administrator »

Simplifier wrote:
Fri Mar 27, 2020 3:26 am
Since my model was being optimised really slowly on my MacBook air (Macintosh with CPU Core i5 1.6Ghz , and 4 GB Ram), for example each simulation run would take at least 5 secs, I purchased a very powerful PC (Windows with CPU AMD Ryzen 7 (3700X) 8 core, and 32 GB Ram) so I could accelerate the optimisation process. I have run the same model with the same features on this new powerful PC, but each simulation run takes about 7 secs.

It has extremely disappointed me as I have paid a lot of money for the new PC and I still do not know why it's running faster on my low performance Macbook Air than the powerful PC. Is it because of the Windows operation system on which the Venism is running slower??
It could be a number of things. Does the new machine have a solid state hard drive? And if yes, are you running the model from that? Many machines have a solid state drive for the operating system but a physical drive for storing files.

You could also try comparing the CPUs directly on userbenchmark.com.

My Windows machine is much faster than my Mac, so operating system is unlikely to be an influence. Multiple cores also make no difference. The main things for performance in Vensim are CPU and hard drive speeds.
Advice to posters seeking help (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391

Units are important!
http://www.bbc.co.uk/news/magazine-27509559

Simplifier
Senior Member
Posts: 51
Joined: Tue Sep 11, 2018 2:04 am
Vensim version: PRO

Re: Low optimisation speed

Post by Simplifier »

Administrator wrote:
Fri Mar 27, 2020 8:33 am
Simplifier wrote:
Fri Mar 27, 2020 3:26 am
Since my model was being optimised really slowly on my MacBook air (Macintosh with CPU Core i5 1.6Ghz , and 4 GB Ram), for example each simulation run would take at least 5 secs, I purchased a very powerful PC (Windows with CPU AMD Ryzen 7 (3700X) 8 core, and 32 GB Ram) so I could accelerate the optimisation process. I have run the same model with the same features on this new powerful PC, but each simulation run takes about 7 secs.

It has extremely disappointed me as I have paid a lot of money for the new PC and I still do not know why it's running faster on my low performance Macbook Air than the powerful PC. Is it because of the Windows operation system on which the Venism is running slower??
It could be a number of things. Does the new machine have a solid state hard drive? And if yes, are you running the model from that? Many machines have a solid state drive for the operating system but a physical drive for storing files.

You could also try comparing the CPUs directly on userbenchmark.com.

My Windows machine is much faster than my Mac, so operating system is unlikely to be an influence. Multiple cores also make no difference. The main things for performance in Vensim are CPU and hard drive speeds.
Yes the machine has ssd. I transferred the files to the ssd and started running the optimisation through there. But still the same.
I also used the benchmark website. It ranks my new cpu extremely faster and more powerful than my mac's. I dont know what else to do. May I email my model and its files to you to do an optimisation run on your system?

Administrator
Super Administrator
Posts: 3522
Joined: Wed Mar 05, 2003 3:10 am

Re: Low optimisation speed

Post by Administrator »

Please do (vensim@vensim.com).
Advice to posters seeking help (it really helps us to help you)
http://www.ventanasystems.co.uk/forum/v ... f=2&t=4391

Units are important!
http://www.bbc.co.uk/news/magazine-27509559

Simplifier
Senior Member
Posts: 51
Joined: Tue Sep 11, 2018 2:04 am
Vensim version: PRO

Re: Low optimisation speed

Post by Simplifier »

Administrator wrote:
Fri Mar 27, 2020 9:18 am
Please do (vensim@vensim.com).
Thanks.

I just sent all the files.

tomfid
Administrator
Posts: 2937
Joined: Wed May 24, 2006 4:54 am

Re: Low optimisation speed

Post by tomfid »

I don't think the SSD will matter much for optimizations, because it's not writing much data until the end.

I didn't notice in your first post that it was a Ryzen 7. This could be an AMD/Intel difference. Historically, AMDs had more cores, but Intels were about twice as fast per core. I thought they had caught up on per-core speed with the Threadrippers, but I haven't tested one. It's possible that's the difference.

There's potentially something we could do on our side to recompile with some AMD-specific extensions enabled, but that won't be an immediate fix.

If you need speed, you should definitely be compiling. Using the Microsoft Visual Studio Community Edition is free for small teams and pretty easy to set up.

Simplifier
Senior Member
Posts: 51
Joined: Tue Sep 11, 2018 2:04 am
Vensim version: PRO

Re: Low optimisation speed

Post by Simplifier »

tomfid wrote:
Fri Mar 27, 2020 1:19 pm
I don't think the SSD will matter much for optimizations, because it's not writing much data until the end.

I didn't notice in your first post that it was a Ryzen 7. This could be an AMD/Intel difference. Historically, AMDs had more cores, but Intels were about twice as fast per core. I thought they had caught up on per-core speed with the Threadrippers, but I haven't tested one. It's possible that's the difference.

There's potentially something we could do on our side to recompile with some AMD-specific extensions enabled, but that won't be an immediate fix.

If you need speed, you should definitely be compiling. Using the Microsoft Visual Studio Community Edition is free for small teams and pretty easy to set up.
Thanks very much for the tips.
I also responded to your email with few more concerns. I appreciate if you can kindly cover those as well.

tomfid
Administrator
Posts: 2937
Joined: Wed May 24, 2006 4:54 am

Re: Low optimisation speed

Post by tomfid »

If you have some time to experiment, I'd be interested in some timing comparisons between your Ryzen machine and my Intel-based workstation.

tomfid
Administrator
Posts: 2937
Joined: Wed May 24, 2006 4:54 am

Re: Low optimisation speed

Post by tomfid »

I just ran a test on a Ryzen 9 3900x. According to benchmarks, it should be faster than my dual Xeon workstation. But it was 4x slower. I'll investigate further.

At the moment, the best bang for the buck is probably a fast i7 or i9. Core count will matter in the forthcoming parallel version, but otherwise you want clock speed.

Post Reply