140hour Renders on Terragen 3 with GTX750 2GB and 8Core AMD

Started by HecubaAssassin, December 12, 2017, 06:53:48 AM

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HecubaAssassin

I have found the render times so slow on my main system, I tend to do them all on my second system which is also and 8core AMD.  Clearly this software does not take advantage of the huge boost a GTX750 can give a system.  I am told by techies that the graphics card is faster than my 8core system... and is slightly better than what a PS4 uses natively.

Stats here on my 2 year old system... AMD FX-8300, 8GB DDR3 RAM  NVIDIA GeForce GTX750 2GB.   5GB across 2 hard drives...

My 4 year old system... is a slower AMD 8-core with 8GB RAM.   This runs at around 60% of the render speed in Terragen compared to my newer system. 

By my calculations it should be a lot slower...
Is it just failing twice, once not supporting a non-Intel architecture, and then not using the graphics card?  I hear that Terragen 3 and 4 never use the graphics card for a heart beat, which is sad having those mege GPUs sitting there soaking up power, doing nothing.

The perplexing thing is that I get renders that will take over 140 hours to do...  And then on a clean boot it works fine.

HecubaAssassin

I will say the 140 hour renders are very complex with multiple planetary objects, 4 or 5 modified clouds layers, and 5 or 6 populations (very thinned out).  Detailed lighting, mostly turned off for the area.  Or just usual renders with more detail.  When it works perfectly, rendering in under 3 hours at 3840x2160, I touch nothing in the settings... just add more hard disk swap space to 1,350kb.  (Somewhere fter about 1,500kb it hurts instead of helps.)  Then I use one cloud layer and 4 or 5 populations, at high density... in one area.  And adjust as needed.  With multiple added elements... including water, but nothing too big.

Oshyan

It's hard to be sure without seeing the details of your scenes and how much memory they would use in an unconstrained environment, but my very first guess as to why you are sometimes (but not always) seeing crazy render times is due to having only 8gb of RAM. Terragen 4 in particular uses more memory than Terragen 3 to render objects and the new "v3" clouds. This produces both higher quality and faster results (faster in the case of objects), but it does need more memory to work. The problem then with having 4-5 cloud layers and big populations (even if they are "sparse") is you're using a lot of memory and eventually you start to swap to disk. You *never* want to use swap space on disk (even with an SSD) when rendering, it is far too slow and will cause a dramatic increase in render time.

So my recommendation would be to upgrade the RAM on both machines if at all possible. RAM is still fairly cheap and 16GB will get you a lot further with large scene rendering than 8GB.

If you want us to run some tests on your scenes to see if there is anything unusual going on, or any way to optimize your settings for faster render, feel free to send them to support AT planetside.co.uk

- Oshyan