render performance

[wannabeArtist]

Hello,

I just upgraded my desktop with a new quad core processor and the 64-bit version of Windows 7 with hopes of shorter render times.

I have to say that at least out-of-the-box it isn't that impressive - unfortunately I wasn't wise enough to record the times on the renders with my old set up (Vista 32-bit and a dual core), but I would say the improvement is rather modest.

Is there something I should do to make sure I'm using the hardware efficiently?
I did check from task manager that all four cores are munching on the render, but that's about it. I also doubled the memory to 8Gbs and raised mental ray's limit to 6 Gbs, but that doesn't seem to be the bottleneck - not much of that seems to get used on the scenes I'm working on.

One more thing: Does anyone know a way to stop Windows from going to sleep during rendering? Of course I can turn the feature completely off, but I would prefer a "smart" sleep.

[wannabeArtist]

I've been trying to play with mental ray's optimization settings, but no real improvements - tips are still very welcome, especially those specific to 64-bit, if any

I set up distributed rendering last night out of curiosity. It started working quite nicely, after reading the tips on this thread. However my render time only shortened a little, from 1:36:32.15 to 1:16:38.05 for a single frame (ok, some settings are pretty high).

The slave is not as efficient as the main computer, but I kind of expected more
Is there a difference between the efficiency of tile-based and frame-based distribution? Because it seems like my slave didn't get all the tiles it could have handled.

[Rork]

A 64 bit version of Windows doesn't automagically render scenes quicker, at best it renders at the same speed. Most of the time it's a bit slower due to the 64bit 'overhead'.

What should be of influence is the quadcore vs. the dualcore and the upgraded amount of memory.
You should see at least a performance increase of about 80%, and that warm fuzzy feeling of having MR not complain about memory problems anymore ;)

If you don't see any performance gain in your scenes with your updated hardware, there's something really wrong and you'll might want to have a good hard look at your settings.
Also, did you try other tests, e.g. video encoding to see if this -is- faster?

Tilebased rendering looks good on paper, but basically sucks in real life. The amount of traffic created on the network most of the time cancels out any performance gains. If you can keep it up and running in the meantime. There are tons of threads on people getting really frustrated with it. Better install a render manager and distribute frames.

About sleepmode in W7, no idea, but some Google'ing will probably help you out there.

rob

[wannabeArtist]

Thanks for clarifying that!

It was stupid of me not to record the times on the renders with the old setup. Now there isn't an easy way to compare them anymore.

I don't see any issues with MR's memory consumption though, but I wasn't having that much trouble with it before either, not after I tweaked the virtual memory size as instructed somewhere.

But what comes to performance, I would estimate it to be a far cry from 80% improvement, in fact it feels more like 8%! Yet, looking at task manager, all cores are doing 100% during render. It might be of course, that my scene is being wasteful somehow with textures for example or that my fg/photon settings are too high, but still it should be much faster than on the old machine.

I had that hunch about tile-based rendering - thanks for confirming that

[Rork]

Hi,

Maybe you could verify your rendertimes on somebody's 32bit Softimage.

I went from a dualcore, 32 bit Windows/2Gb RAM/Softimage v7 to a quadcore 64bit Vista/8Gb RAM/Softimage v2010 and saw a speed increase of about 80-90% depending on scene setup.

Only 10% speedincrease with a hardware upgrade like that, there's something really wrong. I've heard of mobo's/BIOS setups throttling down the CPU speed to conserve energy. I would give the entire hardware setup a good look.

rob