RAM shortage consequences

Super cheese sandwich

What could happen if I the image I have to render needs 30 gb and I have only 12?

 

Thanks

SixDs

Assuming that your machine has been configured to do so (it usually is by default under Windows), once your RAM has been exhausted, the operating system will switch to Virtual Memory for any excess - basically it will use a portion of your hard drive as though it were memory. There must, of course, be sufficient free space available for the purpose on your drive(s). When the system starts using virtual memory, there will also be a performance hit as your hard drive access and transfer rates will be slower than that of your RAM.

System memory management has evolved over the years in attempts to ensure that the CPU is kept supplied with the data it requires and thus maintain system performance. As a consequence there are several types and levels of memory in use, depending upon the task. The fastest memory is that built-in to the CPU die itself, referred to as cache memory. Although relatively limited in size, the cache memory ensures that the most important or immediately required data is available to the CPU without delays, and there are actually several layers or types of this on modern CPUs - L1, L2, etc.. Next in speed is your system RAM, which is not quite as fast as cache, but of far greater capacity. Finally, slowest but of potential greatest capacity is the virtual memory mentioned. The memory controller on the CPU is responsible for ensure which memory is used for what data, and exchanging data between the different types as required, to maximize performance. Unfortunately, VRAM on a video card is not part of this subsystem, nor does it have a similar subsystem of its own, so what you see is what you get.