Could you rely on Virtual Memory on your PC?
Wow. Great post! Thanks.There are new DIMM modules that are being supplied with a hybrid type of technology that includes the same tech found in solid state hard drives. Similarly, new hard drives are being designed with a RAM designation in mind. It would not be unusual to see your idea in motion 5 to 10 years or now if it is deemed feasible or possible by major motherboard manufacturers. As there are already hybrid hard drives (with a SSD partiton for the OS and conventional drive for the files), we are beginning to see an evolution in how we understand volatile and non-volatile on a traditional system. However, running the entire system straight from a pagefile or cache today would be disastrous. The type of change you are talking about would require a new chipset - one where the processor knows to look for memory in multiple locations, capable of sustaining a large amount of bandwidth. To give you an idea of how much bandwidth DDR3 can consume vs. the pagefile even on a SSD, it is something on the order of 10,000-15,000MB/s on modern systems. When you are talking about a SSD the max read/writes are something like 600MB/s on a SATA-3 SSD, which does come close to old RAM speeds, but could never match the voltage and high bandwidth consumption needed by the processor. RAM is typically used by the processor, dedicated, at all times, and would not be able to function properly with "writing things to disk".
There was a time in computing where everything was loaded into RAM - the opposite of what you propose. Floppy disks were loaded to kickstart the OS, specifically on Apple and Commodore systems. After that, everything resided in memory. There was no way to "save" anything other than re-installing a floppy. Those days are over, but how RAM is used and how we perceive memory on a modern computer will change over time.