"No matter what the initial reason for implementing the pagefile system was, pagefiles are still used, even heavily used by Windows today as nowadays available software has developed as well, not only available RAM, and are much more demanding today than they were back in the days when there's much less RAM available.
Especially on gaming PCs there are programs running which need a lots of your installed RAM to perform properly, but also video post processings, packing/unpacking, streaming and such processes ... at worst all at once, require a place for Windows to swap data which are not urgently needed at the moment but will be needed later again. And that's what the pagefile is for.
Always let Windows manage this file/those files, unless you're absolutely sure what you're doing and know how large it should be (btw, Windows already recommends how large it should be). To prevent unnecessary fragmentation and HDD activity you can set a fixed size by setting the same value for min and max size. This way it won't be shrinked and then increased again depending on the workload. But to set the correct sizes you have to have a proper understanding of what Windows is doing with it and when.
The old 1.5 times your RAM rule still seems to hold true, as this is always Windows' own recommended pagefile size. So, for a 16 GB RAM machine it would be something about 24 GB pagefile size (recommended).
I don't know if it is useful or maybe even bad to have several pagefiles, I for one have a fixed size of 2 GB min/max on my boot drive (HDD) for partition C and a managed one on an SSD. But I was searching for pros and/or cons to have more than one pagefile or not, as I tend to delete the 2 GB on my boot partition. Alas, haven't found any valuable arguments yet, but I assume, just for the crash dump files and stuff, it's useful to allocate some GB for Windows' where the pagefile resides normally by default. Hence I leave it like that. But for the other SSDs where my games are installed I do not have any pagefile. Wouldn't even know which size they should have to make a difference, whereas I also don't want Windows to occupy another up to 24 GB on each SSD (or at least 16+ GB as it uses now for the managed pagefile)."
"The only advantage to setting the page file elsewhere is to distribute I/O operations. This was important in the old days, when memory was costly and small, and so programs competed for memory and swapped each other out of memory to the page file. Nowadays, when memory is counted in the gigabytes, the usefulness of this file has become rather doubtful. The only advantage to setting the page file elsewhere is to distribute I/O operations. So, the short answer is : don't worry too much about the page file. The long answer is that if you do have more than one physical disk (meaning real disks, not partitions of the same disk), it might be worthwhile to allocate the page file on another disk, although for every argument for it I can find one against ..."
"The page file is still used and will continue to be used regardless of how much RAM you have. Under XP and earlier (and I THINK this holds true in Windows Vista, 7, and 2008) the pagefile allows memory dumps for debugging but must be on the C: drive for them to work. That said, in 15 years, I've never had a need for a full memory dump so I generally recommend moving it OFF the C: drive when space is an issue on workstations.
I've never heard or read anything to suggest multiple page files have any negative effect. I would appreciate anyone with knowledge of this to post a link describing the issue - preferably from Microsoft's web site, but other sites may do.
If you put the page file on multiple physical hard drives, Windows tries to identify the least used drive and use that for paging operations. So if you have multiple physical hard drives - as opposed to one hard drive partitioned - moving it can be a good idea.
Now, that said, I don't know how much improvement you would see with it on multiple physical disks, especially if you kept the need for paging to a minimum by having a good amount of physical RAM."
