31-03-2010, 10:54 AM
full report
31-03-2010, 10:54 AM
full report
10-04-2010, 12:26 AM
05-09-2012, 02:18 PM
Virtual Memory
2Virtual Memory.pdf (Size: 128.83 KB / Downloads: 38) Physical and Virtual Memory V-Ray uses both physical and virtual memory but let's keep this simple. V-Ray uses MEMORY, period. It doesn't separately access or allocate physical or virtual memory. Your operating system handles how physical and virtual memory are being allocated, not V-Ray. So, when V-Ray starts a render it's going to allocate MEMORY to satisfy its needs (based on a lot of settings of which I will explain the most important and most common settings later on in this article). It doesn't care nor knows what type of memory is being used - physical or virtual. That's being handled by the OS. Now, there's a limit to how much memory V-Ray can use based on what operating system you are using. A default Windows 32 bit version installation (XP / Vista) will not allow you to use more than 2GB per application because it's not able to access larger memory blocks (it’s a mathematical limitation of 32 bits). In practice this means you will run into problems once your render is nearing the 1700MB - 1800MB range, since there's also a lot of overhead in each process (= application). If you use the /3GB switch in your boot.ini you are able to have your applications use up to 3GB of RAM. This limit includes virtual memory and is on a PER APPLICATION level. Remember though, if the application doesn't support the IMAGE_FILE_LARGE_ADDRESS_AWARE value in the .exe header it will never be able to access memory blocks over 2GB and the /3GB switch would be rendered useless!! This executable header value is a special value (actually it's an API - Application Programming Interface) that was made available by Microsoft to allow programmers of 32 bit software to access memory blocks larger than 2GB. So if you have say 4GB of physical memory and a 6GB page file set up (and no additional switches enabled in the boot.ini), your application could for instance use 800MB physical memory and 1200MB page file space depending on what other applications are running at the same time. These other apps also use physical memory of course (as do the OS and kernel!) so you will never have the entire 2GB - 3GB (depending on boot.ini switches) available for your application! Your operating system controls how memory is allocated to applications. CONCLUSION The tips and tricks mentioned here are just a small collection of things you can do to save memory / optimize performance. Also, some tips are V-Ray specific while others will work with and for all render engines out there. It’s truly impossible to list all of the available options to tweak and configure 3DS Max and V-Ray to perform optimally. Read up on and experiment with the options available and you will eventually start to understand how they work. Understanding your render engine is imperative to be able to achieve quality results while maintaining decent render times / memory flow. The ability to successfully render certain scenes might actually depend on your knowledge of your render engine! I hope this document gives you some food for thought and maybe some of the tips will actually solve some of your problems (I’m sure they can!). As always, questions are welcome and if required / wished we can discuss certain aspects or methods in-depth on the forum. |
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