You love taking photos. You carry your DSLR or mirrorless camera along wherever you go. You’re always checking out new Photoshop filters or interesting editing applications. You have a Flickr Pro or Smugmug account, and you upload hundreds of photos a year. Now you want a PC that can be responsive and fast when you're editing and tweaking your pictures.
Whether you build your own system or buy one off the shelf, several considerations are key to choosing the right mix of components for a photographer's PC. You want robust storage, a balance between CPU and graphics performance, and a great display. But before I dive into speeds and feeds, let’s consider a photographer's requirements.

Meet the Photographer

Every photographer shoots a little differently, has varying workflow needs, and takes a unique attitude toward their photos. In this article, I’m going to talk about a PC as it meets my photo-editing needs and my workflow, which may not be the same as yours. Consider this a rough guide, with rules of thumb that apply to most photographic applications.
Currently I use a Nikon D800 DSLR, and I almost always shoot in raw mode. Raw mode captures the pure sensor data, performing no compression or modification on the data it collects. That translates to large files, and the need to have a photo editor that works well with Nikon’s RAW format. In the past I’ve shot with D7000 and D300 bodies. (I'll discuss software in more detail shortly.)
I shoot a variety of subjects, ranging from flowers to landscape to sports action. I've taken the liberty of sprucing this article up with some of my shots to illustrate what a good production rig allows a user to do.
I prefer shooting with ambient light whenever possible, but I do use flash when necessary. I also own a lighting kit for shooting product photos in my home studio. Here's a quick look at the gear I carry.

Whatever gear you use, a good PC for editing and archiving digital photographs will have a few common elements. Assuming that you hang on to most of your photos, you’ll need lots of storage. Photo editing, particularly involving effects such as HDR and noise reduction, requires good performance. If you’re editing large RAW images (12 megapixels and beyond), lots of memory helps. You’ll also want to display images as accurately as possible, so a good monitor is a must.
Rather than discuss a lot of hypotheticals, let’s take a look at a real-world system: my own production PC. Bear in mind that I don’t use this computer only for digital photography--I also use it for some light video editing and PC gaming. I’ll break it down by each major component type, and I'll suggest alternatives as appropriate.
After going over the needs for a good desktop PC, I’ll walk through what you should have when you’re on the go. In some ways, choosing a laptop for mobile photo editing is both more complex and simpler.

CPU and Memory

Right now, my production PC carries a Core i7-3930K CPU. The 3930K is a six-core CPU built on Intel’s 32nm manufacturing process, so it isn't using the latest-generation Ivy Bridge architecture. It costs about $560, and requires a motherboard that supports an LGA 2011 socket. Such motherboards can be pricey--particularly if you’re into heavy-duty overclocking--but I’m content to run the 3930K at its default settings, so in my system the CPU lives in a Gigabyte GA-X79-UD3 motherboard, which is available for under $240.
My machine also has 16GB of RAM, in the form of four Kingston HyperX LoVo DDR3-1600 modules. These modules can run at full 1600MHz (effective) speed at 1.5V. All of this helps the system consume less power. And that 16GB of RAM comes in handy when I have multiple raw images open: The D800's 14-bit raw files range from 45MB to 48MB each, but while I'm editing, they consume more memory than the disk space they occupy.
Alternatives
The 3930K CPU contains six cores, and can execute 12 simultaneous threads. That much power may be overkill for many users, so a good alternative is a CPU in the new Ivy Bridge line, such as the Core i7-3770K. Clocking in at 3.5GHz, the 3770K runs four cores and up to eight threads. It’s capable, it costs around $350, and it's quite power efficient. You can buy a Core i7-3770 (note the lack of the “K” suffix) for a little less money. That version of the chip is not overclockable, but most users shouldn’t care.
In addition to supporting Hyper-Threading, the Core i7 CPUs offer large L3 caches, which improve performance in most editing applications. If you’re eyeing a laptop, ideally you’ll want a Core i7 CPU, mostly because i7 processors have larger caches than their Core i5 and i3 siblings.
As for the system's memory, if you edit lots of raw files, I still recommend 16GB of RAM, given that today’s memory-module prices are pretty low.

Storage...and More Storage

If you’re at all like me, you’re shooting a ton of raw images. You may not be using a Nikon D800, but even 12-megapixel raw images consume at least 10MB of disk space each, while 12-bit, 16-megapixel images eat up 14MB to 16MB.
Storage begins with the flash memory cards you use in your camera. Recent developments in flash memory storage technology have afforded us products with very high-speed data rates. The fastest 1000x CompactFlash cards can move data off the card at roughly 120MB per second. The fastest SD Cards are now capable of read speeds up to 95 MBps. Write speeds are slower--closer to 70 MBps for the fastest CompactFlash cards, and only in those cameras with high-speed controllers.
But let’s not get too concerned about the write speeds of flash memory cards for our photographer’s PC. It’s moving data from the card to your PC that can become a bottleneck in the workflow. If you have a 32GB flash memory card packed with 350 45MB RAW images, moving them off the card is an exercise in patience with a USB 2.0 reader. Ideally, you’ll want a USB 3.0 reader connected to a USB 3.0 port. I own a US Robotics USB 3.0 reader that works reasonably well.

PC Storage Guidelines
Where do you put all those photographs? Whatever you do, don’t store them on the boot drive if you can avoid it. At a minimum, you’ll want two drives in your PC. Currently, I have a single, 512GB solid-state drive as my boot drive. A half-terabyte is enough to hold all my applications, as well. My secondary drive is a single 2TB, 7200-rpm Seagate Barracuda XT. If you’re concerned about data integrity, you might want a RAID 1 array for your secondary drive, which holds all the Windows user folders, including photo storage. (RAID mirrors two physical drives. You get only half the space, but each volume is a duplicate of the other, preserving your data if one drive fails. Remember, though, that even RAID 1 is no substitute for a good backup plan.)
I need to hammer home two key points when it comes to desktop PC storage for photographers:

• Have more than one physical drive. A good combination consists of an SSD for a boot drive and a large-capacity hard drive or RAID 1 array as secondary storage. Even if you’re using standard rotating storage, having two physical drives will improve performance. By keeping applications on the primary drive and photo storage on the secondary drive, you help to increase data throughput. More-sophisticated users can put scratch files on the secondary drive as well, also improving performance.
• Develop a good backup strategy. Even if you’re running a RAID 1 array, you aren't completely safe from disaster, since a catastrophic PC failure can kill the array. Making regularly scheduled backups of your photos is critical.

Be somewhat wary of using external drives as primary storage. I’ve had drives go into sleep mode at awkward times, or lose sync over eSATA. Even with high-performance standards such as eSATA and Thunderbolt, external drive connections aren’t always reliable. External drives can be handy for backups, however. I happen to use a NAS (network-attached storage) system for backups, but locally attached external storage is fine. Just make sure you have enough capacity.
For laptops, try to avoid 5400-rpm or slower hard drives. It’s great to have a lot of capacity, but most photo applications create a large scratch file on the storage device, and waiting for a slow drive to grind through your editing chores is no fun.
What About the Cloud?
People have spilled lot of virtual ink discussing whether to back up data to cloud storage. I don’t use cloud storage for general backups--it’s expensive and time-consuming. If you’re a subscriber to online photo sharing sites, though, you often can use such services as a kind of cloud backup just for your photos. For example, Flickr Pro costs only $20 per year, and allows unlimited uploads of full-resolution images.

Graphics Card

The GPU is increasingly important in today’s computational environment. Photo and video editors are rapidly incorporating GPU acceleration into their products. The graphics card doesn’t just serve to accelerate the display and scroll the canvas; it also acts as a parallel compute engine for a number of filters, particularly blur filters.
Why worry about GPU acceleration? Photo-editing applications are increasingly offloading some work onto the graphics card. Most of these applications use OpenGL and OpenCL, two key software programming standards. OpenGL focuses purely on graphics, while OpenCL allows developers to use the GPU for general-purpose parallel compute tasks, such as blur filters. For example, Photoshop CS6 uses both OpenGL and OpenCL. Corel AfterShot Pro uses the graphics card to assist in file-format conversion. Chinese programmers have built an entire photo-editing application, MuseMage, from the ground up using GPU acceleration.

That said, you don’t need one of those $500 objects of gamer desire to power your photo editing. I confess that I’m running a Radeon HD 7970 in my system, which is priced close to $500. As I mentioned before, though, I also use my system for PC games. If you’re not a hard-core PC game player, you can get by with a relatively low-cost, midrange card. You can find a Radeon HD 7770 for around $150. If you want a little more GPU horsepower, a Radeon HD 7850 costs about $250, and it can do a pretty good job on the occasional PC game too.
Nvidia-based cards also work well; the main reason I’m currently using an AMD card is that AMD has enabled its OpenCL driver. As I noted, OpenCL is a standard for graphics compute chores, such as in Photoshop blur filters. Given the pace of driver updates, however, that could well change in the near future.
A discrete GPU for a laptop is nice to have, but the latest Ivy Bridge processors from Intel have improved the performance of integrated graphics, including GPU compute performance. In the end, a discrete GPU probably will still perform better.

Displays

If you’re serious about photo editing, you should choose a display that you can calibrate to be color-accurate. No monitor is perfect, of course, but some offer much better color fidelity than others do. Prior to buying a monitor, you might want to read up on LCD panel technology.
My general rule of thumb is to use high-quality displays with IPS or IPS-based LCD technologies. Unless you’re doing pro-level print work, you don’t necessarily need a professional-grade monitor, but you do want a display that will fully support true 8-bits-per-pixel color. IPS displays used to be fairly pricey, but their cost has come down considerably. You can find good-quality 24-inch IPS monitors supporting 1920-by-1200-pixel resolution for under $400.

Similarly, if you’re looking at laptops, try to find one with an IPS panel. They exist, but they tend to be among the more premium models. Asus, Dell, HP, and Sony all ship laptops with IPS displays. More pixels are better on a laptop, as well--look for a native resolution of 1600 by 900 pixels or better.
Note that many modern LCD screens offer wide-gamut options. Be sure to set Windows to display the correct gamut for your monitor. Just type color management into the Windows Start menu search box, select Advanced Color Management, and then choose the Advanced tab.

You’ll also want to set the correct ICC profile for your display. Usually you can find the profile included on a CD that ships with the display, or you can download it from the manufacturer’s website. If the process seems a little overwhelming, you can bypass all these confusing settings by using simple tools to calibrate your display.
Monitors: More Is Better
More pixels are better--and more displays are also better.
On my desktop system, I have three 30-inch displays that each support 2560-by-1600-pixel resolution. My main display is an HP ZR30w, which is technically capable of 10-bits-per-pixel color. I also use an older HP 3065 and a Dell 3008WFP, though the Dell often pulls double duty by being connected to one of my test systems. I've calibrated all three using the Spyder 4 Pro calibration puck and software.
You don’t need three displays, but having two is extremely handy. Generally I run Photoshop on the ZR30w and have Adobe Bridge running on the 3065. Even lower-cost applications, such as Lightroom, support dual displays. Simply put, having two monitors makes your workflow more efficient. Note that you don’t have to use two high-end displays--the secondary monitor can be a lower-cost model, though having similar displays is ideal for calibration purposes.

Shoot!

Photo editors, like cameras, are merely tools to get the photograph. The art and craft of the photographer are what really makes photographs shine. You get better as a photographer only by shooting and editing photos. Having the right PC hardware and software, however, will make editing chores just a little bit easier.