Image-Editing Speed Demons
If Photoshop is your business, and work is piling up, two things can make your life easier: techniques that improve your workflow and hardware that doesn't keep you waiting. Throughout this book, you'll find the former, and in this chapter, you'll find information on how various parts of your system work with Photoshop and how you can speed things up.
Dual Processor Prowess
The processor (technically, central processing unit or CPU) is the brain of the computer, the part that does the mathematical calculations on which virtually all computing is based. The faster the CPU, the sooner your work is done. Adding a second CPU to the machine can improve performance by allowing two "brains" to share the work, by simultaneously working on filters and performing other calculation-intensive processes.
Photoshop is tuned to take advantage of multiple processors in both Windows (except Windows 98, which does not recognize the second processor) and the Mac OS. Mac OS X itself is dual-processor aware, further improving performance. Most, but not all, of Photoshop's filters can take advantage of a second processor. However, the speed gains might not be noticeable except with very large files.
The Processor Wars
You might notice that this discussion studiously avoids the questions of Mac/Windows and Intel/AMD, and makes no mention whatsoever of specific processor speeds. Processor capabilities change with furious speed, so anything written the day this book is sent to the print shop will be outdated before copies hit the bookstore.
There are numerous resources on the Web (some of which are impartial and unbiased) that compare various processors and computers in both benchmark (laboratory) tests and real-world situations. Photoshop is often used in the testing because of the demands it places on a system as well as the number of high-end computers on which it runs.
A few words of advice: Ignore the megahertz (or gigahertz) rating when comparing different types of chips. A Pentium III and a Pentium 4 at similar clock speeds perform differently. A Celeron processor and an Intel processor at the same megahertz rating work differently. A Macintosh G4 at 1GHz is faster than a Pentium 4 at 1GHz. How much so depends on the tasks being performed. (Apparently, it also depends on who is doing the testing, which leads to the next point.) Be aware of the sourcevarious manufacturers have a vested interest in making their product look good in testing. Likewise, some "independent" Web sites have links to a particular manufacturer or platform.
Among the most dependable sources of up-to-date information on Windows-compatible hardware are Tom's Hardware (http://www.tomshardware.com) and Upgrading and Repairing PCs (http://www.upgradingandrepairingpcs.com). For information on Macintosh computers, visit http://www.barefeats.com. You'll also find lots of information about both types of hardware at http://www.zdnet.com.
A number of factors other than the processor speed contribute to a computer's performance. System bus (the speed with which data moves to and from the processor), level 2 and level 3 cache (small amounts of memory immediately available to the processor), and a variety of other hardware all play their parts.
RAM Up
Often more important than processor speed is the amount of memory available to Photoshop. The CPU can process information only as fast as that data can move to and from the processor. Information that's available in the computer's memory can get to the processor far faster than information that must be read from the hard drive.
NOTE
Like CPUs, memory comes in several different types. Which is faster, and by how much, is subject to change. Macintosh users have no choice; their computers use only one kind. When building or ordering a Windows-compatible machine, however, a decision may be necessary. Check the links mentioned earlier (see the sidebar "The Processor Wars") for current information.
The price of RAM is extremely low. Many systems can be filled with their maximum amount of RAM for under $200. It's critical that the correct type of RAM be installed. Check the documentation that came with your computer for its specific requirements.
Seeing the Big Picture
Monitors are available in a variety of sizes and a pair of technologies. Cathode ray tubes (CRTs) are the large, heavy, TV-looking monitors. Liquid crystal displays (LCDs) are the thin, elegant, lightweight monitors similar to those found in laptops and other portable computers. Each has advantages:
CRTs are generally less expensive for a given monitor size.
LCDs have more usable screen space at a given monitor size.
Color calibration is still a young art for LCDs. However, some Apple LCDs are self-calibrating, and some hardware calibration equipment for LCDs is now available.
LCDs are generally easier on the eyes and sharper than CRTs.
That having been said, the price of LCDs is rapidly coming down, and the technology continues to improve.
The monitor itself really doesn't have much of an impact on the speed with which Photoshop runs. Rather, it is the video card (the circuit board to which the monitor is attached) that may be a factor. Most modern monitors have multiple resolution and color depth settings available. (The monitor resolution is set through the operating system's control panels or system preferences.)
The higher the resolution, the greater the number of individual pixels that have to be refreshed (updated) to change the screen's appearance. The greater the color depth (the number of different colors an individual pixel is capable of displaying), the more information is required for each pixel. The greater these two requirements, the higher the demands on the computer's video card. There are several different chip sets (technologies) available. If you have a choice when ordering or designing a system, remember that Photoshop is primarily a 2D graphics program. If you also work with digital video, 3D, or games, you might want to make those requirements your priority.
Perhaps more important than the chip set is the amount of VRAM. VRAM is memory built into the video card for the purposes of speeding onscreen performance. Generally speaking, more is better. Ensure that your chosen video card has enough VRAM to power your monitor of choice at the required resolution and color depth.
If you have multiple video cards (or a dual card), you can use multiple monitors with Photoshop. Two or more monitors can be set up to serve as one extended screen. Photoshop (and other programs) enables you to use the entire space of multiple monitors as one large work area. Multiple monitors are set up and controlled through the operating system.
Storage for Now and Later
Another factor that affects the speed at which Photoshop runs is data storage. Photoshop must write to and read from disks. The most obvious examples are opening and saving files. The speed of the hard drive is important, as is the technology linking it to the computer.
Internal Hard Drives
Internal hard drives are typically either small computer system interface (SCSI) or advanced technology attachment (ATA). Portable computers typically have ATA drives. ATA is the official name of Integrated Drive Electronics (IDE), which was developed by Western Digital and Compaq. SCSI is generally a faster interface technology, but ATA/IDE drives are considerably cheaper. Both SCSI and ATA come in different varieties, with a wide range of capabilities.
Keep in mind that not all SCSI drives are created equal. There are, give or take a few, eight varieties of SCSI available that differ in how fast they can transfer data. The original SCSI (SCSI-1) has a maximum burst speed of 1MB/sec, but the most recent SCSI implementation can reach 320MB/sec. Table 3.1 shows the maximum burst transmission speeds by SCSI type.
Table 3.1 Burst Transmission Speeds by SCSI Type
Version |
Maximum Data Transfer Rate |
SCSI-1 |
5MB/sec |
SCSI-2 (Fast SCSI) |
10MB/sec |
Fast Wide SCSI |
20MB/sec |
Ultra SCSI |
20MB/sec |
Wide Ultra SCSI (aka Ultra Wide) |
40MB/sec |
Ultra-2 SCSI |
80MB/sec |
Ultra 160 |
160MB/sec |
Ultra 320 |
320MB/sec |
Likewise, there are varieties of ATA/IDE technology. Typically, you'll see ATA/33, ATA/66, or ATA/100, with the number signifying the maximum transfer rate in MB/sec.
Both SCSI and ATA can be used for other types of hardware, too, including CD and DVD drives and scanners. ATA allows only two devices per connector, but more recent versions of SCSI can link up to 15 devices.
External Hard Drives
External hard drives, drives not physically located within the computer itself, are easily added to most computer systems. In addition to SCSI, you have the option of drives using Universal Serial Bus (USB) and FireWire (also known as IEEE 1394). USB is also used for keyboards, mouse devices and trackballs, drawing tablets, digital cameras, scanners, printers, and more. You'll find FireWire connectors on hard drives, scanners, printers, digital still cameras, and digital camcorders. Both USB and FireWire enable devices to be connected and disconnected while the computer is running (unlike SCSI), but that's not a good idea with hard drives.
NOTE
Remember that USB and FireWire are connection technologies. The drives themselves are ATA/IDE. When shopping, check to see whether you're looking at an ATA/66 or an ATA/100 drive.
USB now comes in two varieties. USB-1 has a maximum data transfer rate of 12MB/sec, and you can attach as many as 127 devices in a single USB chain. USB-2 offers speeds up to 16MB/sec. FireWire's top speed is currently 400MB/sec. A chain of FireWire devices can include up to 63 pieces of hardware. Some portable hard drives have both USB and FireWire connectors.
RAID
When two or more hard drives are arranged in an array (the computer sees them as a single device), you can establish a RAID. RAID, which stands for redundant array of independent (or inexpensive) disks, can be used to provide increased data protection through redundancy or to speed system performance in read/write operations. There are several different types of RAID, as shown in Table 3.2.
Table 3.2 Possible RAID Configurations
Level |
Description |
Drives |
RAID 0 |
Data striping, highest performance |
2 |
RAID 1 |
Disk mirroring, data protection |
2 |
RAID 0/1 |
Combines data striping and protection |
4 |
RAID 5 |
Data striping with parity |
3 |
RAID 0/5 |
Combines RAID 0 and RAID 5 |
6 |
The number of drives listed is the minimum necessary for each level of RAID. RAID 0/1 is also referred to as RAID 10; RAID 0/5 is also referred to as RAID 50.
For Photoshop, RAID Level 1 is most appropriate. It writes the identical data to two (or more) drives, providing data protection through redundancy. If one drive fails, the data is still safe (you hope) on the other RAID drive. RAID Level 0 is more appropriate for digital video and other applications in which it's necessary to record huge amounts of data as quickly as possible. It works by using the arrayed drives as a single drive, spreading the data among them. Because the data is being written to two (or more) drives simultaneously, it can be recorded almost twice as fast. It's rare to need this type of hard drive performance in Photoshop, but there might be some workplaces for which it is appropriate.
Recordable Media
Hard drives can be reserved for data that is used often. The operating system and your programs need to be on the hard drive(s). Files with which you're working should be on the local hard drive. However, there's no need to clutter your hard drive with archives of files. Older files can be recorded to recordable media, such as CD-R, CD-RW, DVD-R, Zip, Jaz, optical disks, tape drives, and, in some cases, even floppy disks.
The advantages of storing files on removable media include security, data protection, and convenience. The files can be kept safe and secure by storing them in an appropriate container and/or location. Labeling the media makes it easier to locate a specific file. In addition, your hard drive is less cluttered, making it simpler to find and work with current files.
The various types of media have their advantages (prices noted are, as always, subject to change):
3.5-inch Floppy DisksFloppies are virtually free these days. Ask a few friends and colleagues, and you might find yourself buried in old, reusable floppy disks. There is a reason for that, however. Floppies hold only about 1.3MB of data, are slow, and are not particularly reliable. Floppy drives are no longer standard on all computers, and Apple Computer no longer offers them at all. (There are, however, many third-party floppy drives available.)
Zip DisksIomega is the manufacturer of both Zip and Jaz drives. Zip drives come in 100MB and 250MB varieties. The larger drives can read both types of disks, but the older drives work only with the 100MB disks. Basically oversized floppies, these drives are not fast. The 100MB disks cost $9$10 each, and 250MB disks generally retail for $14$15 each.
Jaz DisksJaz drives and disks come in 1GB and 2GB varieties. The large amount of storage space is offset to some degree by a huge price tag. In addition to the cost of the drives, the media are very expensive. The 1GB disks cost about $80 each, with 2GB disks available for about $100 each.
CD-RThese disks are write once/read forever. Once you record (or burn) a CD-R, the disk is permanently recorded. Recordable CDs hold about 650MB or 700MB each and can be purchased for as little as $0.25 each in bulk (without jewel cases or paper sleeves). Although recording is often slow, the disks can be read very quickly.
CD-RWThe RW stands for "rewritable," meaning that you can record these disks over and over. You can write once and later add more info to the disk, or you can erase it and start over. CD-RW disks generally must be recorded and read at slower speeds than CD-Rs. They are also more expensive, costing between $1.25 and $2.00 each (with cases).
DVD-RHolding 4.7GB of data, these disks are the larger kid brother of CD-Rs. Like CD-Rs, DVD-Rs can be recorded only once. They can be purchased for $6$10 each.
DVD-RAMAs DVD-R is to CD-R, so DVD-RAM is to CD-RW. Think of them as a very large brotherdouble-sided DVD-RAM disks can hold as much as 9.4GB of information. (Single-sided DVD-RAMs hold 4.7GB.) Expect to pay $15 for one-sided and $35 for two-sided disks.
CAUTION
If you're recording files to CD for archival purposes, don't buy discount media. The low-cost disks can be much less reliable. This is especially true if the CD will hold the only copy of an important file.
Tape back-up systems can also be used to store files, as can magnetic-optical (MO) drives.
Dedicated Scratch Disks
Another way that hard drives affect Photoshop's performance is when serving as scratch disks, which are hard drive space set aside for Photoshop to support the memory. When Photoshop is idle, it copies the contents of the allocated memory to the scratch disks. In some cases, Photoshop has to handle more information than can fit into memory. The program then uses the scratch disk space as though it were additional memory.
NOTE
Photoshop works with scratch disks much the same way that the operating system works with virtual memory. The primary difference is that Photoshop alone controls scratch disks.
Scratch disks can be assigned by using Photoshop's Preferences (see Figure 3.1). By default, the startup drive is used as the scratch disk, although up to four drives can be assigned. Theoretically, there is no limit on the amount of scratch disk space. Photoshop accesses the drives in the order assigned.
Figure 3.1 If there is more than one hard drive or partition on the computer, use Preferences, Plug-Ins & Scratch Disks to assign scratch disks.
It's important that the amount of available scratch disk space be at least equal to the amount of memory allocated to Photoshop. If 512MB of RAM is available to the program, but only 50MB of free space on the scratch disk(s), Photoshop uses only 50MB of RAM.
For optimum performance, add a small, fast hard drive to your system and use it exclusively for Photoshop's scratch disk. The disk need be only somewhat larger than the memory allocated to Photoshop. (A 2GB drive should be adequate.) By dedicating a drive to scratch space, you ensure that there's never a delay in reading from or writing to the drive.
Here are some additional guidelines for Photoshop's scratch disks:
If multiple hard drives are available, put Photoshop's primary scratch disk on a drive other than Startup. (That's the drive used by the operating system to support the memory. It's best if the OS and Photoshop are not trying to read/write at the same time to the same drive.)
If there's only one physical drive, but it has multiple partitions, keep the scratch disk on Startup. (You don't want the OS and Photoshop trying to write to separate areas of the same drive at the same time.)
If there are multiple drives available other than Startup, use the fastest drive as the first scratch disk.
It's a very good idea to defragment drives used as scratch disk space. That eliminates the slowdowns caused by the drive jumping from place to place to find an area in which it can write.
CAUTION
Never use removable media or network drives for Photoshop's scratch disks. Using such drives can lead not only to slowdowns, but also to program failures.