Rendering in SketchUp

38
Part 1: Overview and Concepts
the Computer Processor
The most important computer component that determines rendering speed is the central 
processing unit (CPU). More commonly referred to as the processor, the CPU affects stages 2 
and 3 of the rendering progression. 
Processor count is analogous to the number of cylinders in a car engine: the more cylinders, 
the more powerful the engine and the faster the car can go. The more processors your com-
puter has, the faster renderings will be completed (Fig. 4.4). 
Fig. 4.4: 
Processors can be compared to car engines. 
Generally speaking, each additional processor halves the rendering time. If a render takes 
one hour with a single processor, it will take 30 minutes with two, 15 minutes with four, and 
10 minutes with six. The differences are significant.
Multiprocessing
Multiple-core processing computers have become standard. Currently, computers come with 
dual-core (2), quad-core (4), or six-core (6) processors. The number of processors used can be 
expected to continue to increase. 
However, more processers do cost more money. The cost for a decent quad-core rendering 
computer currently ranges from $1,500 to $2,200. In the future, you will see computers with 
six, eight, twelve, and more cores available for the same price. This revolution in processing is 
one of the main reasons the average SketchUp user can now create photorealistic images with 
IRPs. When SketchUp was first released, and for several years after, this was not an option 
because processing power was either too expensive or not available. 

---

39
Chapter 4: How Rendering Works
If you’re buying a new computer for rendering, make sure you buy the most processors you 
can afford. Currently, the Intel i5, i7, and Xeon chips are the most cost-effective processors to 
use for rendering. They are available for both Macs and PCs.
Computer processors are also rated by processing speed, which is measured in gigahertz 
(GHz). The faster the chip, the better it is for rendering. 
Unless you have to have the latest bells and whistles, avoid the top of the line or recently 
released chips. The cost-to-benefit ratio of these chips is minimal.
RAM and Computer Memory 
Random-access memory (RAM) is the amount of memory that is available for the processor 
to use to read and write data. The more RAM you have, the larger the model the computer can 
process. Insufficient RAM can cause a render to crash or fail.
RAM is measured in gigabytes (GB). A typical computer possesses 2 to 8 gigabytes of RAM. 
Large complex models usually require at least 4 GB of RAM. With 8 GB, you should be able to 
render most models with no problems. If you’re rendering light sources such as bulbs and fix-
tures, or models with large amounts of three-dimensional vegetation, you might need from 8 
to 12 GB of RAM.
A typical system comes with 4 to 8 GB of RAM and is relatively affordable.