Trying to understand GPU speeds and cycles

I am wanting to understand the speeds of using cycles on graphics cards.

I currently render on my dual core CPU @ 2.4ghz as my current graphics card is a 8600 GTX and it is not much faster.

If I were to buy a faster computer with top graphics card - what sort of speeds would I be looking at compared to my CPU?

5x faster? 10x faster?


Seems to me that you might be comparing apples with oranges. If you are comparing a CPU-based (i.e. “BI”) render with a GPU-based (“Cycles”) render … well-l-l-l … might we (not?) agree that the only characteristic that these two things actually have in common with one another is: that both of them produce as their output “a graphic image that looks like a car.”

We humans like to think in terms of “… it’s a (real) car.” But a computer really has no idea what “a car” is. In both cases, an input data-set (a great big file of numbers…) is merely being presented to “a computer algorithm” to produce an output data-set. Which data-set, “oh, by the way,” when properly displayed by the appropriate software, “looks to our human eyes like a picture of a car.” But the "a computer algorithm"s in question are entirely different, because the hardware that has been tasked with carrying out each respective algorithm is as different as … well … an apple and an orange. :slight_smile:

You have to approach each version of the problem with careful consideration of the nature of the hardware that will be employed to solve it. At the risk of presenting an analogy that is too absurd: “If what you have to work with is a (pocket calculator | statistical package), you’d do this; whereas if what you have to work with is an (abacus | electronic spreadsheet), you’d do that.” Both “to generate a picture of the same car.” Both “to generate pictures that look pretty similar to one another.” Both to exploit the unique advantage of each platform|strategy while minimizing its weaknesses.

A solution “for BI” quite naturally will play into the strengths of BI, artfully avoiding its weaknesses; whereas a solution “for Cycles” quite naturally ought to play into the strengths of Cycles, artfully avoiding its weaknesses.

In Cycles. If you were to put, say a GTX560Ti in your box, yes, at least 10x faster, maybe even 20x faster. It is one h*ll of a diff. ;D

thanks for your replies.

I am rendering Cycles on my dual CPUs - my card is old and really not as good - and so I want to buy a new cards - or computer.

I just wanted to gain some perspective on how fast GPUs were compared to a CPU.

As my rendering is REALLY slow :frowning:

For rendering in Cycles, if that’s your issue, but a new card.

The thing is, if you put a faster card in your box, the rendering will get X times faster without you changing anything else. So it’s a very economical way compared to upgrading to a new box. But you need to go GTX460 or faster for all functions in Cycles (*) and you will need to upgrade your PSU to runt that kinda card. A doubt a box like your have more than 3-400w PSU now and you’ll need a 550w PSU for such a card.

(*) Like my GTX285, it will render beauty-pass, but not AO, depth, all that… You need GTX460 or better for all functionsm - or render on the CPU, but that’s slow. As you know. :wink: