How to Speed Up Rendering Time

[Bill Tillman]

One thing I can hopefully share with everyone is how to NOT speed up rendering time.

 

The attached render was done yesterday in Presentation mode at 1024 x 768 on a computer with an AMD Athlon 64 4000+ 2.4 GHz processor with 3 GB of RAM. This machine was running Windows Vista Ultimate x32 with AutoCAD 2010 x32. At the time I was running MS Outlook sending a few e-mails, lightly surfing the web and checking back on the render now and then. It took 1 Hr 44 min to complete.

 

This morning I put in a new hard drive and installed Windows Vista Ultimate x64 then installed AutoCAD 2010 x64. I purposely did not run anything else on this machine, only AutoCAD 2010 x64 and opened up the same file and allowed the render to run in Presentation mode at 1024 x 768 resolution. It took 1 Hr 25 min to complete.

 

While a little bit faster I certainly did not get the results I was expecting. I realize this scene is very slow because I have the sun and sky with illumination enabled. I also know that I can drastically speed up the render time by using a background instead of the sun and sky. But still one would have thought that by using an OS that's processing twice as fast it should have cut the time in at least half.

 

What is exactly the trick to get the speed one is investing in with the x64 OS and x64 version of AutoCAD? Let's all remember the point of this question is not to inquire how to speed up this render. There are many suggestions I'm sure that would speed it up. The purpose of this inquiry is to find out why the faster OS and copy of AutoCAD did so very little in doing the same thing one can do without investing more $$$ into the process.

[Cad64]

What is exactly the trick to get the speed one is investing in with the x64 OS and x64 version of AutoCAD? Let's all remember the point of this question is not to inquire how to speed up this render. There are many suggestions I'm sure that would speed it up. The purpose of this inquiry is to find out why the faster OS and copy of AutoCAD did so very little in doing the same thing one can do without investing more $$$ into the process.

 

The faster 64 bit OS is not enough. I ran the same tests at work with a 32 bit machine vs. a 64 bit machine, with each machine having the exact same specs. The only thing that was different was the operating systems. But the render times did not decrease very much with the 64 bit OS.

 

In order to speed up render times you need multiple cores and more RAM. If you had a 3.0Ghz quad core processor and 8GB RAM you could probably cut your render time down to about 20 minutes. But just switching out the OS is not going to help much.

[Bill Tillman]

Okay, it took me some time to finally get my hands on a monster machine but I just built an i7 Quad Core 920 with 12 GB of RAM. I have installed Windows Vista Ultimate x64 OS and AutoCAD 2010 x64.

 

Two weeks ago a rendering I was working on with AutoCAD 2010 x32 on an AMD64 machine with Vista Home x32 took about 45 minutes. This same rendering took 23 minutes on this new high-performance machine. Not the improvement I was looking for but still an improvement nonetheless. Was it worth the $1500 I spent on this machine, not really especially when you factor in the cost of the software which has now exceeded $5K over and above the cost of the machine.

[Cad64]

The new machine cut your render time in half. I would say that's a pretty dramatic improvement. What exactly were you expecting? If you look at my previous post, I said "you could probably cut your render time down to about 20 minutes." Looks like I hit the nail on the head with that estimate.

 

If you're looking for 'real time' rendering, it ain't gonna happen. At least not yet. The technology just isn't there yet.

 

What you need to do now is start looking at your scene and figure out what you can do to further reduce your render time. I'm no expert with rendering in Autocad, so I can't really help you with that. But if you can post your scene file, along with materials, I can take it into Studio Max and play around with it and let you know what kind of render times I'm getting. Then maybe you can apply similar techniques in Autocad. I really think that image you posted could be rendered in less than 10 minutes with the proper set up.

[ReMark]

To achieve dramatic render reduction times you'll have to build your own render farm. Start by reading this...

 

http://www.extremetech.com/article2/0,1697,1815797,00.asp

 

Otherwise a computer utilizing a quad Quad-core (16 cores), (2) Raptor 15,000 rpm (150GB) hard drives and 16GB of the fastest DDR SDRAM might be a good start. $1500 for a computer isn't all that expensive. A really ripping one would have set you back anywhere from $4500 to $8000.