Computer Setup
This page discusses various options for setting up a computer for use as a DAW. This includes choosing hardware (outside of the audio interface), hardware installation, BIOS settings, and OS settings.
Hardware
Hard Disk Drives
Uncompressed digital audio can be quite large. When dealing with multiple tracks and banks of samples, audio production will require lots of reads and writes from your hard disk drive(s). Thus, the faster the better - disk drives are typically slow and can easily create a bottleneck in an otherwise fast system.
Solid State Drives
I recommend using a Solid State Drive (SSD). These are essentially lots of RAM in an enclosure, removing the mechanical operations of a traditional hard disk. This means there is no head seek time or need to spin the disk to the correct sector, which create wait times. When files are fragmented or multiple files need to be read/written simultaneously (almost always the case in audio production), these operations are constantly occurring, massively slowing down the disk's overall throughput. Operating systems use the disk as a spillover from RAM for temporarily cached data, adding to the importance of hard disk speed. SSD's are thus much faster in this regard.
Interface
There aren't many disk interfaces to choose from these days. Commercial servers often use SCSI, while most consumer computers use ATA. ATA is almost always found as Serial ATA or SATA these days, and SATA has several versions, which correspond to the maximum possible speed. SATA I is 150 MB/s, SATA II 300 MB/s, and SATA III 600 MB/s. Obviously, higher/more is better. SATA III is well established and doesn't carry a significant if any price premium over SATA I and II.
Some brands may advertise SCSI for audio production, but most SATA implementations are actually faster than older parallel SCSI interfaces. Check the actual throughput numbers - only more modern serial implementations like iSCSI, SCSI express, Fibre Channel 8/16Gbit, SAS 3.0/4.0, and USB SCSI 2.
For more see Wikipedia - SATA and SCSI.
Spin Speed
For traditional disk drives (not SSD), the speed of how fast the disk spins can improve its read/write performance. Typical hard drives operate at only 5,400 rpm; however, 7,200 rpm and even 10,000 rpm disks are available. Faster speeds are recommended; however, keep in mind that disk speed also can lead to faster degradation. You should always be sure to backup your work across multiple disks or occasionally burn it to dvd's or use some other backup method.
RAID Arrays
RAID uses multiple disks operating in parallel, either to provide data redundancy (automatic backup) or increase performance, or both simultaneously. It can be implemented on traditional disks or SSD's.
RAID is not for the light of heart; and it can get expensive; however, it will provide excellent performance as well as reduce risk of losing data. I recommend RAID for backup reasons outright. For performance, I would first recommend a faster hard drive. Only if using a fast drive and you are still having disk bottlenecks that you should resort to doing a parallel RAID array for performance.
USB/Firewire Controllers
North and South Bridge Options
CPU
DSP Chips
Video Cards
Networking
Audio Monitors
Displays
BIOS Settings
BIOS stands for basic input/output system and is basically a low-level operating system specific to certain hardware that allows more robust OS's like Windows, OS-X, or Linux to communicate and control the hardware. It often allows customization, allowing you to change rather technical hardware-related options, such as clock speeds, voltages, the boot order of storage devices, and disabling/enabling motherboard features/ports.
Most BIOS software can be accessed for configuration during bootup by pressing Delete, Escape, or one of the Function keys (F1 - F12).
Power Saving Features
Most modern computers feature numerous power saving features. Usually these can be disabled via BIOS, and I recommend doing so for two reasons.
Power-saving features such as C states and Turbo Boost for the CPU work by shutting off power to CPU cores when they are not in use. Sounds good and it usually is. But for DAW usage with processor-intensive real-time audio streams, offline cores may often need to be brought up in the middle of recording or bouncing tracks, resulting in latency at best and hiccups/crackles at worst.
My computer had some nasty EMI/RFI being emitted that was certainly getting into my guitar pickups, regardless of how well they were shielded...any high-gain sound picked up what sounded like a modem - lots of somewhat high-pitched droning, pulsing garbage. I tried pushing the case further back - helped a little but holding the guitar in certain positions still sounded bad. I tried unplugging everything I didn't need - USB devices, printers...eventually I had everything unplugged from the wall and computer except the computer itself and my Kemper. I tried plugging everything through a power conditioner. I tried swapping the power lines used on the modular power supply. Nothing helped. Finally I decided to try BIOS and disabled all the power saving features. Eureka! I'm not sure if the CPU itself is the problem (AMD FX-8 8120), or the motherboard, or how the PSU switches to regulate voltage when the CPU is enacting such power saving, but whatever it was the issue is now resolved and I can move on with my life <3.