How To Build A Faster 3D CAD PC

This is a special guest post from GrabCAD user Scott Bruins

For an updated (7/2015) post with more modern specs and prices, click here.

Tired of trying to do 3D CAD on an outdated system? Can you read a novel in between rebuilds? Waiting days for a rendering? It may be time to upgrade your workstation. In this article I’ll go over what you need to know to build a fast 3D CAD PC.



The general rule of thumb when it comes to a CAD workstation is that, the CPU is king. The majority of CAD operations are CPU based so it's a good idea to get the best one you can afford. The better the processor, the faster your rebuild and rendering times will be. The speed of a processor is referred to as its “clock speed” and is measured in GHz. The core count refers to how many cores per CPU. For instance, a 3.2GHz hex-core processor has 6 cores, each running at 3.2GHz.

More cores vs. higher speed?

Now, do you spend your hard earned cash on a CPU with a higher speed or more cores? That depends on what kind of work you will be doing, rendering or CAD design?

When rendering, you want as many cores as possible to get faster render times. A common misconception is that rendering is performed by the graphics card, when it is primarily CPU based. A even though rendering is primarily CPU based, some modern rendering programs can utilize higher end graphics cards for rendering. The graphics cards are essentially turned into an additional processor cores to aid the CPU in rendering.

Now, rendering is a multi-threaded operation, meaning it can utilize more than one processor core at a time. A quad core processor will render much faster than a dual core processor with a higher clock speed. The more cores you have, the faster you can render. There are motherboards that support multiple CPUs on a single board. For example, you could have two hex-core processors giving you a total of 12 processing cores.

On the other hand, modeling with 3D CAD software (such as SolidWorks) is primarily a single threaded operation. This means it will only use one CPU core at a time. So when speaking about CPU's in regard to 3D modeling, the higher the clock speed, the better the performance. It may seem odd, but a dual core processor running at 3.5GHz will rebuild a complex part faster than a quad core running at 2.5GHz.

Many processor are also capable of running at much higher speeds than advertised by the manufacture. The process of manually increasing your CPU’s clock speed is called “Overclocking”. With overclocking you can increase your processors performance by changing timing and voltages of the processor to achieve a higher clock speed.

Overclocking often requires improved cooling for the processor such as a larger heat sink or liquid cooling, but can yield significantly improved performance. However, If not done properly overclocking can damage your hardware. So do your homework and proceed with caution! If you are nervous about overclocking, there are several companies that offer pre-overclocked computers with a warranty.

3D CAD PC CPU Cooler

Graphics Card

After the processor, the graphics card (GPU) is considered the second most important piece of hardware. The graphics card handles the visual display of the model when you roll, pan or zoom. For 3D CAD applications you will need a professional, OpenGL graphics card.

There are are two main brands of workstation cards, the NVIDIA Quadro and ATI FirePro series. These graphics cards range in price from $100 all the way up to $2,000+. These OpenGL cards are considerably more expensive than their DirectX based “gaming” counterparts, but are necessary for most 3D CAD applications.

The easiest way to think about the difference between OpenGL and DirectX is an OpenGL card calculates higher detail models at relatively low frame rates, while a DirectX card calculates lower detail models at high, sustained frame rates.

When choosing a graphics card you want to keep in mind the type of work you will be doing. If you work on very large assemblies with lots of models you will want a graphics card with more memory. If the graphics card does not have enough memory, the frame rate will lag or stutter when moving the model. However, most users won’t need more than 256MB memory and can get away with a cheaper card.

It is possible to use DirectX cards for 3D CAD, however some features may not function properly (such as SolidWorks RealView) and you may experience slow frame rates as well as graphical glitches.

Hard Drives

Although not as important as a CPU or graphics card for CAD work, the hard drive can have a significant impact on overall performance. Hard drive technology has come a long way in the past few years. With the rise of the Solid State Drive (SSD) transfer speeds have increased dramatically.

The fastest traditional disk drives have a transfer speed of around 100MB/s, while modern SSDs range from 120MB/s to 750MB/s (and getting faster!) The faster transfer rate of the SSD will let you save and open models faster, make programs start faster, and decrease your computers boot time.

The downside of the SSD is its cost. Although the price has come down significantly in the past few years, an SSD is still considerably more expensive per GB. That being said, in my opinion an SSD is worth every penny. The massive performance increase over disk drives is very noticeable. Because of the cost, it is a good idea to use a small SSD as the main drive for the operating system and programs, and a high capacity disk drive as a media/storage/backup drive drive.


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If you build it, it will rock!

So now, when it's time for an upgrade, you’ll know what you need to build a screaming 3D CAD eating monster! Check out all the computer parts on GrabCAD and design your own custom PC. I will keep an updated list of components for a budget performer and dream machine below. What are you running now? What is your dream system? Let me know in the comments!

Budget Performance System (Workstation): Updated July 11, 2011
CPU: Intel Core i7-2600K Sandy Bridge 3.4GHz
Motherboard: GIGABYTE GA-P67A-UD4-B3 LGA 1155 Intel P67
Graphics Card: ATI 100-505682 FirePro V5800 1GB
SSD: OCZ Vertex 3 VTX3-25SAT3-120G 2.5" 120GB
HDD: Western Digital Caviar Green WD20EARS 2TB
RAM: Mushkin Enhanced Blackline 8GB
Cooling: CORSAIR H80 (CWCH80) High Performance Liquid CPU Cooler
Case: NZXT H2
PSU: CORSAIR Professional Series Gold AX850

Approximate Cost: $1,743.86

Dream System (Rendering) : Updated July 11, 2011
CPU: 2x Intel Xeon X5690 Westmere-EP 3.46GHz LGA 1366
Motherboard: EVGA Classified SR-2
Graphics Card: 4x PNY VCQ5000-PB Quadro 5000 2.5GB
SSD: OCZ Vertex 3 VTX3-25SAT3-480G 2.5" 480GB
HDD: 4x Western Digital Caviar Black WD2002FAEX 2TB
Cooling: Custom Liquid Cooling
PSU: CORSAIR Professional Series Gold AX1200
Approximate Cost: $15,000-$17,000

Scott Bruins is CAD designer/drafter at a machine shop that specializes in high precision medical implants and devices. He specializes in SolidWorks 2011 and rendering with PhotoView 360.

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