Thinking about buying some new simulation hardware? Make sure to check out our updated ANSYS Hardware Requirements page to read about the many factors that affect simulation performance, including our recommendations on how to get the most out of your hardware investment. Notable updates to returning readers include the importance of keep it in memory and more detail on storage recommendations. I’ll also highlight a few interesting developments on the hardware horizon.
Importance of Storage
With Solid State Drives (SSDs) becoming cheaper and RAID0 arrays of SSDs becoming feasible due to TRIM support, SSDs are starting to go from a luxury to a baseline for new simulation hardware. If you are commonly performing one of the following types of I/O bound analysis:
- Out of core Sparse Solver in Mechanical
- Block Lanczos Eigensolver
- Distributed Memory Parallel (DMP) solves (in SMP, there is one set of files, in DMP each core has its own set of files and IO becomes a bottleneck)
- Transient FEA or CFD runs where many results are being written to disk
…then you will see fantastic speedup from increasing storage performance. ANSYS R18 Mechanical allows you to specify a custom project scratch directory so you can automatically take advantage of specialized high performance solve drives.
The top of the line storage solution is a RAID0 array of SSDs. Make sure that your SSD/OS supports TRIM on RAID0 arrays specifically, like on this page, or you will see decreasing write performance over time.
Read more in the Updated Storage Section
Even Better than Storage: Memory
Improving storage performance is well and good but many times the best performance is to use the disk (Mechanical or SSD) as little as possible. For some types of analysis using the disk is unavoidable but what you really want to avoid is not having enough memory so that the CPU uses the disk in place of memory. The disk is the slowest type of memory, with the system memory (RAM) being faster and the on-CPU cache (different levels of which are called L1/L2/etc…) being the fastest you can get. To compare the relative speeds of these memory levels we can use the metaphor from this article:
- L1 Cache: Grabbing a piece of paper from your desk (3 seconds)
- L2 Cache: Picking up a book from a nearby shelf (12 seconds)
- System Memory: Taking a walk down the hall to buy a Twix Bar (4 minutes)
- Accessing the Hard Drive: Leaving the building and roaming the earth for 1 year and 3 months
While the CPU is accessing these various memory levels it is sitting idle. The difference between those last two levels is why you should always get as much as memory as possible!
Read more in the Updated Memory Section
Don’t Forget to Upgrade Your Software Too!
Another way to get the most out of your hardware is to keep up with current versions of ANSYS. Every new release there are improvements in solve time, pre and post processing time and ease of use. In addition to these there are some improvements to HPC licensing as well with the latest release:
- 4 cores with the new Fluids Packaging: In addition to giving you DesignXplorer/Fluent/CFX, all levels of the new CFD Package come with 4 cores to get you started on running your simulations in parallel
- 1 HPC Pack = 10 cores: Those first cores that you parallelize will often have the greatest effect on your simulation time. With the new HPC Pack licensing, you get 10 cores off the bat.
Some Interesting New Developments
AMD has come back in force with their new Ryzen CPUs. They are especially good for multi-threaded applications so there is definite application to ANSYS:
— Jeff Kampman (@jkampman_tr) March 23, 2017
What’s happening in this mysterious picture, taken at the SVEC Banquet earlier this year?
Contact us to schedule a visit to find out!
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