Viewing and manipulating large models requires significant compute resources. For post-processing FE and CFD results three areas control the amount of wall time required to generate each image: number of CPU’s, available system RAM and Video Cards. This post focuses on video cards with information provided from benchmarks performed by PMI. It is shown that the latest generation of video cards provide significant improvements in performance over video cards that are a few years old.
Based on initial tests that we performed for benchmarking our machines we found large differences in machine performance depending on the hardware that was available. Additionally, with the release of Star CCM 10.02, CD-Adapco has started supporting GPUs. With measurable performance differences between machines with different hardware and the new support of GPUs we decided to perform additional benchmarks to determine a good machine configuration, primarily for pre and post-processing of CFD models.
Description of Cards Used for Benchmarks:
- Nvidia FX3800 (workstation card) (http://www.nvidia.com/object/product_quadro_fx_3800_us.html). This is the primary video card used by PMI for the last couple years. The cards have provided acceptable performance, but we were starting to get persistent OpenGL errors, primarily with SolidWorks, Hypermesh and Star-CCM+. Based on internet research, we believe this is because the card only supported OpenGL 3.1. 4gb Of memory.
- Nvidia GeForce GTX 660 (desktop card) (http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-660). This is a great midrange video card with 2gb of memory.
- PNY Nvidia Quadro K4200 (workstation card) (https://www.pny.com/nvidia-quadro-k4200). This is a beast of a card with 4gb of memory.
The test model was about 34 million cells and had a file size of 15 Gb. The test started by opening a Geometry scene followed by a velocity scene. A mesh scene was then opened and the model was rotated through the same increments using standard view controls in CCM+.
Below is a table of the recorded times with each video card.
|FX3800||660 Windows Driver||660 Nvidia Driver||K4200|
|(Vel already open) Metal Temp Scene||2m55s||1m48s||1m48s(crashed)||1:50|
|MT, rotate, +x+y+z to -x+y-z||1m43s||1m28s||(crashed)||0:02|
|MT, rotate, -x+y-z to +x+y||1m54s||1m25s||(crashed)||0:02|
CCM allows you to specify Nvidia Graphics or Windows.
The GTX660 with Nvidia driver would crash when trying to load the second scene. We could never figure out exactly why it wouldn’t use some of the pc’s resources for the left over memory needed.
You can see the K4200 is an amazing card. The initial load times are about the same but when it comes to rotation there’s nothing even close and yes that is 2 seconds. By the time I started the timer and looked up the rotation was complete. This is huge when exporting images to create a video. The code and sample video can be found HERE. Workstation cards are designed for specific types of work. In this case the workstation cards are a must.
When installing multiple cards make sure you are removing all of the old drivers. When installing the new drivers there is an option for clean install. In the test computer I used a software called Display Driver Uninstaller. Use this program at your own risk.
By, James Greeson