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Testing Dynamic Local Mode on AMD Threadripper 2970WX - Photogrammetry

Written on December 11, 2018 by William George
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Introduction

Dynamic Local Mode is a new feature on AMD's biggest Threadripper processors. These CPUs have cores grouped internally, some with direct access to system memory and some which have to communicate through those other cores to access data in memory. DLM prioritizes running code on the cores which have a direct line to the memory, helping to improve performance in situations where not all of the cores are in use. How does that translate to real-world workloads, though? Let's take a look at two photogrammetry applications - Pix4D and PhotoScan - and see how the 24-core 2970WX behaves with this feature on and off.

Test Hardware

The CPU platform for this had to be AMD's X399 chipset since that is the only option for Threadripper. We utilized the recently-released 2970WX since we already have test data for the bigger 32-core 2990WX, and these are the only two models which support (or need) Dynamic Local Model. If you want to see full system specs, with links to part pages, .

Methodology

In order to be able to test multiple image sets with multiple iterations, we put together AutoIt scripts that run Pix4D and PhotoScan without manual input. Because of the automation we used, all steps were performed back-to-back with no editing in-between to clean up point clouds. That means these results may not perfectly match up with what you'd see when using these programs in a real-world workflow, but it removes any chance of human error altering results between runs. We did still observe small variances on total processing time with each image set, so we ran them three times and selected the fastest result (lowest time) for each image set to be included in the charts below.

As mentioned above, we tested several different image sets: two each in both 3D Model and 3D Map modes within Pix4D, and two models in PhotoScan. No settings were altered from the defaults in Pix4D, while all steps were run at "High" quality in PhotoScan. Descriptions of the image sets we used, and which application/processing mode they were used with, are available below.

Image Sets

Here is information about the image sets we used, including project type (3D Model vs 3D Map), listed in order of complexity:

Pix4D Eagle Model
Eagle Statue Photo Set Point Cloud44 Images from Pix4D website

Pix4D Building Map
Building Map Photo Set Point Cloud36 Images from Pix4D website

PhotoScan Monument Model
Building Map Photo Set Point Cloud32 Images from PhotoScan website

Pix4D Wolf Model
Wolf Statue Photo Set Point Cloud100 Images provided by Pix4D

Pix4D Station Map
Wolf Statue Photo Set Point Cloud739 Images provided by Pix4D

PhotoScan Building Model
Building Map Photo Set Point Cloud50 Images from PhotoScan website

Results

Here are the results for total processing time on each of the image sets, with DLM enabled ("On") and disabled ("Off"):

Pix4D 4.3 AMD Threadripper 2970WX DLM On vs Off Comparison - Eagle Model Image Set with 44 Photos

Pix4D 4.3 AMD Threadripper 2970WX DLM On vs Off Comparison - Building Map Image Set with 36 Photos

Pix4D 4.3 AMD Threadripper 2970WX DLM On vs Off Comparison - Wolf Model Image Set with 100 Photos

Pix4D 4.3 AMD Threadripper 2970WX DLM On vs Off Comparison - Station Map Image Set with 739 Photos

PhotoScan 1.4.3 AMD Threadripper 2970WX DLM On vs Off Comparison - Monument Model Image Set with 32 Photos

PhotoScan 1.4.3 AMD Threadripper 2970WX DLM On vs Off Comparison - Building Model Image Set with 50 Photos

As these graphs demonstrate, there isn't a big impact from DLM - but it does help a little, across the board, in these applications. Performance improvements range from less than 1% to over 5%. It is not ground-breaking, by any means, but if you have a Threadripper 2970WX or 2990WX you will want to make sure you have DLM enabled for the fastest photogrammetry processing.

For those who want details, here are charts showing the time (in seconds) for each step within these processing tasks:

Conclusion

AMD's Dynamic Local Mode (DLM) feature doesn't make a massive difference in photogrammetry applications, but it does improve performance a little bit across the board in our tests. Since this is an easy setting to enable in a free application that AMD provides, it is definitely worth turning it on if you use Pix4D or PhotoScan and have a supported processor.

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Tags: Pix4D, PhotoScan, CPU, Performance, Photogrammetry, Dynamic, Local, Mode, DLM
Lady_AMD

When are you guys going to test the update to metashape?

They say the update "introduces a new method of mesh generation from depth maps, increasing the speed at which detailed geometry can be generated."

Posted on 2019-01-13 16:33:52

I would like to test it soon, but the fact that they changed the branding will likely break a lot of stuff in our test scripts (which often depend on looking at window names, which probably changed). I am about to start in on SOLIDWORKS testing, in preparation for SWW next month. After that, hopefully, I can update our scripts and do some testing of Metashape. I'd also really like to get hold of better image sets to use with that software, though :/

Posted on 2019-01-14 19:43:02