Desktop PCs


Which interfaces do I look out for?

The predominant interface on the motherboard used to connect graphics cards is PCI Express x16. Some motherboards may have two of these types of slots, which means that two graphics cards can be installed in unison. For NVIDIA-based cards, this is called SLI; while for ATI-based cards it's called CrossFire. A motherboard will only support one or the other, but not both. SLI and CrossFire are aimed at enthusiast users and hardcore gamers who want to have the most graphics processing power available to them. All new motherboards will ship with one PCI Express x16 slot, but only high-end motherboards will have two PCI Express x16 slots.


PCI Express

PCI Express, or PCIe, was ratified in late 2002 to overcome the limitations of AGP, which was the old graphics card interface that can't be found in new systems today. The PCIe interface has a higher bandwidth throughput than AGP, lower pin count and lower latency, making it a superior connection interface for graphics. .PCIe can be used not only for graphics cards, but for other add-in PC expansion cards, such as digital TV tuners and wireless networking cards. As such, there are currently four PCIe modes that can be found in today's PCs:

  • PCIe x1 mode (500MBps) uses a single data lane -- both directions
  • PCIe x4 mode (1000MBps) uses a double data lane -- both directions
  • PCIe x8 mode (4000MBps) uses a quadruple data lane -- both directions.
  • PCIe x16 mode (8000MBps) uses 4000MBps per directions.

Nearly all graphics cards are of the PCIe x16 variety.


Which memory?

Graphics cards also contain onboard RAM, which is used as a working space for the graphics operations.

The two graphics memory types you are likely to encounter are DDR3 (Double Data Rate) and DDR4 (this can be found in some high-end cards). Some budget cards also feature slower DDR2 memory.

A powerful graphics card will have up to 512MB of memory, while a mid-range card will have 256MB (but some can be found with 512MB) and budget cards can also be found with 256MB. A key specification is the memory bus, not just the memory capacity. Two cards that have the same memory capacity will perform differently if they have different sized memory buses. High-end cards can have a memory bus as wide as 512 bits, while mid-range cards have a 256-bit bus and budget cards can have a bus as narrow as 64 bits.

Join the Good Gear Guide newsletter!

Error: Please check your email address.

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

PC World Staff

PC World
Show Comments

Essentials

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Michael Hargreaves

Windows 10 for Business / Dell XPS

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?