In part 1 of Hardware for the CAD Professional, we reviewed the basics of system requirements. In part 2, we defined some commonly used terms. In part 3, we talked about processors and how they can affect your workflow. Part 4 helped you calculate how much RAM you need. Now, let's talk about hard drives.

Hard Drive Capacity and Speed

This is an area where lots of change is happening, both in drive capacity and in connectivity options. It was not all that long ago that the 1TB drives became available, but now there are multi-terrabyte drives in a number of configurations — both for internal use and as externally mounted drives. If you’re creating design files, you’ll want to take advantage of the larger capacities, while paying attention to how much time it takes to save data to the drive and/or back up the drive for security.

RAID Configuration

Many users opt to configure their hard disks in some form of RAID configuration. Among the most common configurations, RAID 0 is the fastest RAID level, using a technique called data striping. It requires at least 2 disks. RAID 1 uses a pair of hard disks at a time to provide fault tolerance (no performance benefit) — it requires at least 2 hard disks. By using disk mirroring, the same data is written to both disks at once, so if one hard disk crashes, the same data is available from the remaining hard disk. There are other RAID configurations, but these two seem to be the most popular for workstations.

I will provide a caveat here — I’ve used RAID extensively in the past, but some bad experiences resulted in data loss and I no longer trust RAID as an option. This is strictly based on my personal experience — your mileage may vary.

Like faster RAM, higher RPM rates on drives tend to provide a percentage point or two increase in performance, so if you’re looking to eke every bit of performance from a system, this may be something you should consider.

SSD Drives

SSD drives store data in solid state memory rather than using conventional hard disk platters. These drives tend to be both speedy and pricey at present, but some hybrid drives combine features of both HDD and SSD in one unit. These hybrid drives typically contain a large HDD with a smaller SSD cache to improve performance of frequently accessed files. These drives can provide fast system startup and fast application loading, while being less expensive than pure SSD drives, but they’re not ideal for data intensive uses.

The old adage about getting a hard drive at least twice as big as you think you’ll need still holds true.

Next, let's talk about connectivity.

Author: Ron LaFon