You've likely heard it before, lurk 3D communities long enough and someone is bound to ask ďwhatís the best desktop for 3D rendering
Ē, "what's the best laptop..." and so on. Well, assuming the question isnít being asked for reasons of idle curiosity, as the saying goes "if you have to ask, you canít afford
Flippancy aside, if youíre specifically asking "what's the best desktop for 3D rendering
" and accompanying the question with a list consumer rated components and parts, you are fundamentally misunderstanding the problem because, frankly, the best desktop
(or consumer-grade 'whatever') for 3D rendering are is not going to be your typical desktop, workstation or thingamajig, but machines built specifically for the task (often as rack units), rendering 3D content in similar fashion to ASIC 'computers' mining bitcoin and only bitcoin - render 'blades' are set-up and managed just to produce rendered output and little else. Not especially cheap, user-friendly or with a great ROI for the consumer compared to the common-garden hardware the end-user might be more familiar with.
So, if youíre serious about wanting to know what the best computer for rendering is because youíre considering an upgrade, what might be better to ask is; "whatís the best desktop for 3D rendering in the $600-$1500 price range
", or "the best desktop under $1000 for 3D
" or some such, that way you set a practical (pragmatic) budget limit on the question that helps others answer more appropriately instead of what normally happens, they shoot for the moon and suggest buying a system stacked with multiple bleeding-edge graphics cards, CPUís and huge amounts of ram (because that's what they have!)
If you want a sensible answer, ask a sensible question.Tips for buying 'the best' computer for 3D rendering
With all that said, depending on your circumstances, the older your current hardware the more options you have for buying better (not necessarily "best") hardware for 3D than you currently have, especially if youíre on a budget. If, for example, youíre still using a second (2xxx) or third (3xxx) generation Intel processor or equivalent AMD, upgrade costs can be kept down looking at used or refurbished desktops, laptops or workstations, hardware one or two generations down the family tree (childrens children), 4th (4xxx, e.g. i7-4790) and 6th (6xxx, e.g. i5-6400) in particular; as newer generation CPUís become available older gear is often sold complete and ready to run much more cheaply than for the cost of a low-end new machine. The same holds true of GPU and graphics cards.
Obviously, this upgrading in this way does mean doing your homework and perhaps watching sites where end-users sell their old desktop and computer components for a reasonable price and in good condition.
With this in mine research CPU and GPU benchmark sites because many commenters responding to the "bestÖ" question often incorrectly suggest you should just get the latest generation hardware because "it beats old generation processors/graphics hands down
". Not true, at least not always, or where it is, a marginal 10 or 15% increase over five generations hardly qualifies as "beats hands down
", certainly not for the additional expense involved.
Where possible stick with branded hardware as they are less likely to have issues with parts and compatibility (hardware age notwithstanding; the older something is the more difficult is might be to source spare and replacement parts).
Within the budget youíve allowed yourself try and max out on RAM; if the system being looked at has a maximum allowance of 16GB, try and source that (in addition to, or to replace, what may already be in the system when purchased). Similarly, try opting for an SSD for the OS (256GB min for Windows 10) and at least 7k rpm hard-drives.
Being frugal, and patient, itís possible to build a workable solution for 3D generally not just rendering, for few hundred dollars that will out perform a new computer in the same ball-park.
 quote apparently attributed to J. P. Morgan.
 this is the digital artist, developer or computer users equivalent to red-Ferrari compensatory activity.