making blender render faster

hi,
im just wonder what affects rendering speed the most (processing speed, memory, etc).
i have an old comp that is rendering really slowly rite now, and only have enough money to add one thing (or 2 really cheap ones). im hoping to use it only for rendering.

Proscessing speed, memory, and I don’t know what else.

imn pretty sure the determinate factor of render speed is the processor

processor type, processor speed, memory size, memory speed, bus speed, etc.

No matter what you do, there will always be a bottleneck somewhere. All of the factors are related. It depends on the specifics of your system.

On low end machines, try tweaking your scene settings first. I hear a few people say things like this transparent cube had 3 million polys and took a couple of hours to render and they maybe use full GI, raytracing and AO.

If you have a subdiv surface, try a lower subd level, use dmap shadows instead of ray shadows, use AO sparingly - I never use it because it’s too slow. Also, don’t hang about to wait on high quality renders, do it at night when you’re sleeping. Render what you need for the time you sleep and use the time during the day to do modelling/animation and use low quality test renders.

You have to remember that Pixar made their first feature movie in 1989. Do you think they had any better computers then than you have now?

Well, the slower the computer the slower the render, it all depends on how fast the comp can do the calculations required to complete the render.

osx, thanks for the inspiration (pixar)
just wondering if using a renderer besides blender’s internal or yafray such as:
http://www.3delight.com/
would go faster or slower?

you can enter the render command from the command window ( the dos window that opens with blender ) the only trouble is i don’t know what the command is,…someone else might though. anyway it speeds up render time.

blender -b filename.blend -f 1 (for a single frame, in this case frame 1)
blender -b filename.blend -a (for an animation)
blender -h (get a list)

Blender’s internal renderer is the fastest renderer I’ve ever seen. It’s designed to be that way at the expense of quality. Yafray, 3Delight etc. are all slower but support more features. Like I say, it depends on the scene settings. If I render the default cube, it renders instantly, but if you use high res geometry, turn on advanced lighting and raytracing and it’ll take much longer.

Check out this image (hit return in the location bar when the page fails):

http://www.geocities.com/ajr650/plantperson.jpg

This had a GI hemisphere and some other lights with anti-aliasing. Ok, it’s not brilliant quality but it’s still an ok image and it rendered in just 40 seconds on my 700MHz laptop. If you want to do very realistic images, older machines aren’t ideal but you just need more patience. As always, just save the looong renders for when you go away for the weekend or when you are asleep. You can easily break animations into segments to render. I did a 30-40 hour long render (the animation was just 1.5min) over 4 nights and didn’t compromise my modelling.

Rendering does take a while if you need the quality. Renderman is the most popular renderer and it’s one of the slowest around but the quality is outstanding. You just have to compromise quality vs speed.

dont like going against the crowd but it is a couple of factors not really metnioned and that is that the vpu processor needs to be atleast 400mhz and the memory should be like 64 minum (although i use 32 right now) and in addition to that your card quality should be good - a good cheap card is the geforce fx 5200 with 128mb ddr ram. you can pick these up for like 60$ and another better alternative is the more expensive but much better quality fx5700 which could run you around 120$. Oh and avoid scams like the fx5700le cause the le part means it is basically a fx5600 which they sell for 90$ but you are going to pay 120$! also pay attention for things like triangles a second - this is the render engine - the higher the better and a good one is more than a billion!

a good place to get these parts is tigerdirect.com or .ca if you are in canada!

hope that is what you are going to get cause they absolutely will improve your render time by about 100%!

other factors are like said - processor but more importantly buspeed cause a amd althlon 64 (with 1600fsb) will creem a P4 3.4 with 800fsb anyday even though the P4 is 1.2 ghz faster! other things are ram - but that is more for actual developement and always go for faster ram not more ram! (if you are buying for new not update) and if your memory is ddr don’t get two different speeds or amounts cause then it doesn’t take advantage of the feauters in ddr memory!

hope that that wasn’t all too confusing pm me if you want more info!

prince

rendering speed has at the moment nothing to do with the graphic card, as blender doesn’t use it for acceleration of the final render. other software like maya or XSI can use it, but the acceleration and quality heavily depends on the supported OpenGL extensions and the way they are implemented.

Yeah, there’s no denying that a faster machine is better for Blending. As Prince quite rightly says, it’s not recommended to have anything less than about 400MHz although laptop and desktop speeds vary. A 400MHz laptop is generally not the same speed as a 400MHz desktop.

For pro work, you really need both processor and graphics card. You’ll find it hard to model hi-res scenes if you have a rubbish card. My Radeon 7500 buckles at about 50000 polys in a scene. I heard a GeForce 4 Ti can do over 1million polys in real-time and the some of the FX series will be higher still.

If you were really stuck for rendering, you could maybe use an online render farm like http://www.ap3d.com/core/render_farm.htm

It would be handy if there was one for Blender users, though they might use Blender if you asked. Maybe just have an XGrid with 1100 G5s for $5million - 3rd fastest supercomputer in the world but the cheapest. :slight_smile: Then just send your blend files away for rendering and get emailed the image back.

well. it can not be reccomended to use a slower computer than a pentium 400 mhz but the fastest computer i blend on is a pentium 2 350 mhz (with 128 mb ram). during my vacation i used a pentium 75 laptop with 8 mb ram. so you can use blender on very slow computers. if you can wait

yes you see that is the thing - the difference isn’t really in the processor speed but in the front side bus speed! you see the bottleneck isn’t at the proccessor but rather at the link between the cpu and the exchange of memory thus your fsb has to be as fast as it can. seeing that you aren’t going to go get a new cpu i’d suggest the vpu - and go for the best you can afford! cards like the geforce4 mx4400 are good for desktops rendering but actual gaming or 3d animation stuff you want to step up to something like the geforce fx5200 with its 1million plus trigs a sec! If you plan on heavy heavy rendering or if any gamers are out there - go for the geforce fx5700 with more than 1.2million trigs a second! this card is a screamer and for only a little more!

in a while i’ll post a thread on what to look for in buying a pc for rendering and cinema production so i’ll link you to it! :wink:

@Prince: As solmax already pointed out, the graphics card has nothing to do with rendering speed in Blender! It affects only the framerate of the viewports.

i don’t aggree with that - more memory and more cpu is better but a vpu is what is going to make a difference if he has such an old computer…(btw post your cpus specs!)…the processor is just fast enough and teh memory (well i agree get more) but he probably still has integrated graphics and so simple graphics card update would be most effective for teh cost and for his application.

i do speak from experience - i have a 32mb nvidia and my dad has a 128mb ati the difference in just the memory alone makes a huge difference - his P4 3ghz with 800fsb ht makes the second difference! If anything the new vpu would allow for better desktop use during rendering! :wink:

prince

like usagi said, graphic cards have nothing to do with offline rendering speed. why that? because rendering algorithms run on main CPU (or better on their FPUs) and NOT on the graphic card.

real time rendering is done by the graphic card. so a good graphis card is improving your blender GUI performance but NOT the speed if you make an image.

this should be quite obvious when you use blender command line rendering. in this case blender can do realy fast renderings on computers with an aged 4MB graphic card if the main CPU is fast.

the memory of the graphic card is just for realtime shading, texturing, meshes and so on. again, it wont help you increase your offline rendering time when making an image (by pressing F12 in blender)

okay i’ll face the facts you’ve presented me! :frowning:

still if he wants to use any other type of renderer taht doesn’t do computational rendering (knock on wood he should ever want to!) he needs a better vpu. Else go for the memory! ast ddr 400mhz or higher and be sure to get matched size and speeds!