More cores or more Ghz? The answer may surprise you.

Did you read the “CadTempo and BricsCAD Performance post series written by Patrick Hughes? He’s the author of CadTempo, and he found some really interesting performance numbers when running batch processes in BricsCAD. Patrick detailed his findings, and we were pretty excited to post them here on the Bricsys Blog. Patrick raised a question at the end of Part 3 of his post regarding CPU performance, and we thought that it would be good to address it here. Your BricsCAD hardware choices will depend on it!

What is a core?

Two numbers are important when choosing a CPU – processor speed (in GHz) and the number of “cores”. Let’s look at Intel’s current Core i7 series. Most desktop i7 CPUs are quad-core processors. “Quad-core” means that there are four micro-code execution units inside the CPU package. You’ll also hear about the concept of “threads”. A thread represents a virtual processor – Intel calls this Hyper-Threading Technology (HTT) – and it’s a way to get more work out of a physical processor core. Each physical processor core is split into two virtual cores or threads. A four-core CPU runs eight virtual threads.

Serial vs Parallel

CAD data – the stuff stored inside your drawings – are structured in a way that creates dependencies between these entities. Because of this, it’s really tough to process them using parallel techniques. The processing needs to be done one entity at a time – serially. BricsCAD can leverage some parallel processing power when loading .dwg files, and when regenerating display objects. BricsCAD can leverage all cores on your PC when you’re rendering an image. However, today – the majority of processing that happens when BricsCAD is running on your PC happens in a single thread.

What does this mean? Quite simply, in a quad-core CPU world, you’ll see BricsCAD – or any CAD application – utilize a maximum of 12.5% on your PC’s performance meter. Not 25%, but 12.5%, because your i7-based PC has eight virtual cores and ( 100/8 == 12.5 ).

So what do I do to get faster CAD?

The fastest BricsCAD hardware platforms are the ones that have the highest single-thread performance (STP). All the data you ever need to make your selection are here at PassMark Software’s site. The higher, the better – but don’t spend foolishly. We’ll let you do the mathematics on price vs. Single Thread performance number. Some of the numbers may surprise you!

We also recommend a Solid State Drive (SSD) as your boot / primary drive, and a fast SATA drive as a secondary. RAM is so inexpensive that we recommend at least 16, if not 32GB, but BricsCAD will run just fine in less than 8Gb of memory.

Finally, most of today’s graphics cards will work just great with BricsCAD. When editing 3D models, these cards will allow you to work in a “rendered” visual style with decent performance. It’s important to know that when you’re editing 3D models, the processing “bottleneck” is usually with the CPU, not the graphic card’s GPUs. If you do a lot of rendering, a high-end GPU will make a significant difference in performance.

CadTempo’s measurement of BricsCAD hardware

Patrick used a Xeon E5-2630 based machine, with an STP of 1,549, and a Core i7-2600 that has an STP of 1,943. The Core i7 should be about 25.4% faster if the difference was based solely on single-thread performance. However, Patrick saw a different result – the time to run the batch script in BricsCAD went from 6m51s down to 3m43s – a 45.7% faster result.

We postulate that the hard drives and disk controllers differ between the two machines, as this benchmark involved opening and saving hundreds of files. We’ll find out more from Patrick and share our findings here.

Conclusion: if you want BricsCAD hardware that runs really fast, get a CPU with the highest Single Thread Performance number possible. Next, set up a fast SSD as your primary disk drive. With today’s low, low hardware costs, it’s easy to build a screaming machine to run BricsCAD!