There have been many topics posted in the Random Musings forum about asking tips & advices when buying a desktop or laptop. So I thought it would be nice to summarize all the useful info here, with fantastic support on this article from Cyberdemon who has already given some great advice on hardware and software questions on the forums.

First of all, the important differences between a desktop and a laptop are the appearance, mobility, upgrade ability, user friendliness and price. A laptop with the same specifications as a desktop is likely more expensive. And in general, people find it more convenient to work behind a desktop than laptop.
So it depends on your purpose and personal preference whether you want to buy a desktop or laptop.

There are a few things you should know about specifications that influence the performance of your 2D graphic or 3D CAD software. For most designers it is important that they can create and manipulate graphics or 3D model renderings as fast as possible.

Processor (CPU)
A more powerful CPU means faster rendering times. Dual and Quad Core processors will drastically improve rendering performance on software that supports multiple cores.

Memory (RAM)
Get enough RAM. More RAM means more displacement/ file textures/ proxies etc you can cope with. 4Gb RAM is usual nowadays, but if you are low in budget then 2Gb RAM is not too bad. If you work a lot with big file sizes like large images in Photoshop or complicated 3D models in CAD software, or if you like to run several applications at the same time, then RAM is really important to make your applications run stable.

It is important to note that 32 bit operating systems can only handle a maximum of 4 gigabytes of total system ram. This means if you plan on working with large amounts of data, you should opt for a 64-bit operating system

Photoshop Tip: For better performance, you can increase the memory usage through the ‘Performance’ settings by going into the ‘Preferences’ menu. Don’t allocate too much RAM to Photoshop because your operating system still needs RAM.

Graphics Card
A more powerful graphics card results in more smoother (higher FPS rate) real time view ports renderings. Always choose a laptop with a dedicated graphics card, which result in better performance in general. On-board graphic cards tend to have unacceptable performance or are not compatible with many modern pieces of software.

Many machines will come with a consumer grade Nvidia Geforce or AMD Radeon chipset. These dedicated chipsets will provide better performance, but may not be compatible with all features of software. An Nvidia Quadro or AMD FireGL workstation class graphics card will provide maximum compatibility with all modern 3D software, and will provide maximum performance in any real time rendering applications. Always remember to properly install and update your graphics drivers to improve performance and resolve possible bugs.

If purchasing a desktop with plans to upgrade the video, keep in mind that you will need an open PCI-Express 16x slot, as well as a power supply that is capable of properly powering your graphics card

Hard Drive
A faster hard drive (7,200 to 10,000 RPM) will improve overall system performance, especially for large video or image editing. Solid State disks while still low in capacity and high in price can provide an extremely fast drive for storing operating system and program files, when coupled with a standard hard drive for data storage.

Furthermore, a high resolution display, or dual monitors are excellent ways to boost productivity. Running dual monitors allows you to easily drag and drop between multiple applications (moving images from Photohsop to Indesign) or allow for a dedicated 3D modelling window while storing menus and other information on the second screen. In most cases 2 smaller monitors provide more overall screen real estate at a lower price then a single large screen. For example two 20″ monitors can be purchased for less then many 24″ monitors.

Please note that your system is a set of interacting parts. In other words, do not spend all your money on CPU only without having enough RAM, which will become a bottleneck.