core i7 rendering

[TP-Oreilly]

In 3ds max, my file takes 3 minutes and 42 seconds to render on my colleges computers, which are i7 920 cpu's, on my computer at home it takes 5 minutes and 28 seconds on a i7 930 cpu. why is mine slower? the only real difference between mine and theirs is that i have 3gb of ddr3 triple channel ram and they have 6gb of triple channel ram, but my file is tiny so i would NOT need alot of ram, plus ive saw benchmarks were the difference between rendering with 3gb of ram and 6 gb of ram is 0! so that cant be the problem i think our graphic cards are similar, plus, when rendering it uses the cpu anyway, not gpu.

any ideas why mine is slower???????

 

[Remeniz]

You mention your friends 'computers' and 920 CPU's, as in more than one computer. Does your friend have a network of computers that share the rendering process?

 

[TP-Oreilly]

nah, its not my friends, its the computer at my college, they are all set up to be stand alone, i know for a fact the render is NOT share by other pc's

 

[Kage]

Does the motherboard automatically overclock the college's computers? I know some that do.

It could be the RAM though, as rendering is very CPU/RAM dependent, and if more information can be stored in the RAM and not retrieved, it could make a difference.
It really depends on the quality of the settings you have set.

 

[TP-Oreilly]

thanks for the information, but seeing as my file is veryyyyyyyyyyy small, and only quickly made it so i could do these tests, surely having 6gb of ram over 3gb of ram wouldnt make a difference,

and the overclock speed of both of our cpu's are both 3 ghz, i checked up on that earlier, so our cpu's are basically the same, running at the same speed.

so in this case would ram stilllll matter?

 

[Celegorm]

What are you trying to render and what is a "small" file? I ask because some small cad drawings can still be 4+gigs in size.

 

[Kage]

Yeah, like I said, depending on settings, even 4GB's of RAM can be used up, because polygons are increased rapidly during render time, and then you have the calculations stored based on light bouncing off a surface. Materials that are more complex are obviously going to have to have more light bounces per pixel. Then you've got to throw in the fact that each pixel is anti-aliased a set number of times.

Trust me when I say RAM does matter.

Rendering a pretty basic scene comprising of around 3,000,000 polygons a couple of years back, I used up a lot more than my 3GB's RAM, even though it ran in the view-port perfectly fine.
I had to render in parts since it wasn't taking it.

It also depends on the resolution you are rendering at.

What I suggest you do, is set a render region, and render a given number of pixels, like say 640x640 and then render on each machine. You'll find the speed, if I'm right, will then be the same.
Or just render a full frame at a lower resolution, and check on each machine.

Then scale the resolution up, until you start noticing a difference between the two.

So render at 320x320
640x640
800x800
1024x1024
1280x1280
1680x1680

and so on

 

[TP-Oreilly]

i have, ive rendered at different resolutions on both of the pcs, mine, and theirs, and they still render about 30% faster or so, the polys in my scene is only 6500, so i dont think ram is the issue here,

 

[Kage]

Yeah, in that case, I have no clue. Resolution would be a factor causing RAM to be more of an issue, but since its not...

 

[TP-Oreilly]

someone told me today that it could be because my graphics card is not as good as their ones, but im 99% sure that rendering just uses cpu????