Mechanical designers demand some of the most powerful workstations available.  The number of mathematical calculations behind creating and manipulating 3D solid models are unfathomable.

The user experience of a person who uses mechanical design software tools is crucial. Mechanical Designers are highly skilled; they are constantly balancing form, fit, and function while meeting marketing/sales requirements and designing for manufacturability to bring a product to market that will meet and hopefully exceed quality requirements – it is a tall order.

It is important that these people be well supported in their work as much as possible so that they can achieve maximum productivity and quality results.

This is where the topic of persistence and non-persistence comes in. For most people, these are probably new terms. For most people, you are accustomed to a persistent compute environment. For users of mechanical design software, they are used to sitting down at their computer in the morning, firing it up and having the environment they left yesterday pop back to life – this is persistence.

The organization VirtualDesktop recently published an article on persistence VERSUS non-persistence. Their article was general in nature for any application. Our article will focus on the implications for the MCAD user.

For Starters – What is VDI?

Before we discuss persistence, you need to understand what a VDI is; because the VDI is what makes persistence a topic to consider. If you have been investigating moving CAD applications into the Cloud, you have probably come across this term – VDI. Virtual Data Interchange, did that help? Not really, I am assuming. Said another way, when you have your heavy-duty MCAD applications like CATIA, JT, NX, PTC Creo, Solid Edge, SOLIDWORKS, etc., the VDI is your access to the cloud-hosted application. The VDI is the thin-client, where the user interface (UI) resides, and that is pretty much it. The heavy-duty crunching is off in some datacenter, just not under your desk.

So, for example, a SOLIDWORKS user could be using an iPad or a ChromeBook as their thin-client VDI while SOLIDWORKS is actually running in the Cloud in a secured location perhaps even using an NVDIA or AMD GPU. Another advantage of cloud computing for the MCAD user is that these expensive GPU resources can easily be shared which can result in huge productivity gains, but this is a topic for another post.

VDI: Persistence V. Non-Persistence

Your laptop or your desktop are persistent. When you turn it on or boot it up, it is just as you left it. Your programs – your files – what you were working on, all of these will be there. A persistent VDI will behave in exactly the same way.

A non-persistent instance would be like sitting down at some else’s desk and starting new every day.

“Advancements in technology have brought together a confluence that is enabling a new computing paradigm,” said Chad Garrish, EpiGrid President and CEO. “And this paradigm can radically decrease costs by reducing capital expenditures and reducing the human capital required to manage design environments, all while increasing the productivity of the designers.”

Alyssa Provazza of VirtualDesktop said about persistent implementations, “The user’s settings are saved and appear each time at login. These types of desktops allow for more personalization, but they require more storage and backup than non-persistent desktops.” At EpiGrid, we believe the personalization is what is important and a more storage is inconsequential.


As outlined in the VirtualDesktop article, they rate persistence with higher marks for user in customization and familiarization; we believe this is directly translates to increased productivity.

Also in the article, they rate non-persistent as having better security. That could be true in some cases, but our recommendation is to implement your VDIs within a private-cloud. The private-cloud VDI implementation offers several advantages, one of which is security – more on this topic in a future blog post.

When moving to the cloud with a persistent VDI, users will have the same experience as they do with their high-performance desktop that sits under their desk. Moreover, they will have some added advantages, such as:

  • Remote access from any internet connected client
  • Scalable computing resources on-demand including access to GPUs
  • Simplified collaboration and file sharing with your team regardless of their physical location

About EpiGrid

EpiGrid provides CAD in the cloud virtualization services (VDI) for the mechanical design industry. Applications include MCAD, PDM, PLM and CAE. In addition to cloud hosting, EpiGrid provides complete managed services for these applications, including the initial implementation.

Companies use EpiGrid to augment existing on-premise computing (hybrid compute model) to complete cloud hosting. Contact EpiGrid to learn more.