SUPER FAST HardDrive/RAMDISK

Never do that! Putting the page file on a RAM disk is the biggest mistake one could do, because it negates the very function of the page file to begin with.

The page file is there to "simulate" that there is more RAM than really is installed. When Windows runs out of memory, it unloads the least recently used (at least, in theory) and saves to disk, so that memory is available to something else. But by putting it in a RAM drive, to simulate that extra memory, you're consuming memory. So, what you gain by the page file, you're losing on the RAM disk.

Because of that, putting the page file on a RAM drive is WORSE than disabling the page file altogether. The ideal place is a second, physically different hard disk, or the system drive if there is nothing better. But never on RAM.

I have never been a fan of using a RAMDisk with a modern OS. It was useful with DOS and 16 bit versions of Windows. But that was a long time ago. Modern operating systems have a sophisticated caching system that provides most of the benefits of a RAMDisk with fewer of the problems.

A RAMDisk provides very fast access to whatever files you have chosen to store there. The system cache is essentially a smart and dynamic RAMDisk. But you don't have to choose what is kept there, the OS does that for you based on actual usage. Portions of files that are frequently accessed will be kept in the cache for quick access. And the contents of the cache varies according to how it is used. And the size of the cache is dynamically adjusted according to current needs. If you are running applications that really benefit from the cache it will grow accordingly, always consistent with overall system needs for memory. On the other hand, if you are using a large application that makes little use of the cache it will be trimmed back.

A RAMDisk offers none of those advantages but it does deprive the system cache of a substantial amount of memory that it could be using to improve performance. If you really understand how the system memory manager works and you really understand how it interacts with your workload you may be able to use a RAMDisk to your advantage. But the odds against that are pretty long.

The pagefile is a particularly bad use of a RAMDisk. There are two possible scenarios here:

1. You have sufficient RAM that diverting a substantial amount of it to a RAMDisk will not significantly impact performance. In that case the pagefile isn't going to be used enough to impact performance anyway and you have gained nothing.

2. You do not have sufficient RAM to spare for a RAMDisk pagefile. In this case the gains in pagefile performance are more than offset by the losses of the RAM for process working set and the system cache. The pagefile is a net drain on performance.

All of this becomes clear when you understand how the memory manager works. That is far to complex to explain here.

Alejandro85 said:

Never do that! Putting the page file on a RAM disk is the biggest mistake one could do, because it negates the very function of the page file to begin with.

The page file is there to "simulate" that there is more RAM than really is installed. When Windows runs out of memory, it unloads the least recently used (at least, in theory) and saves to disk, so that memory is available to something else. But by putting it in a RAM drive, to simulate that extra memory, you're consuming memory. So, what you gain by the page file, you're losing on the RAM disk.

Because of that, putting the page file on a RAM drive is WORSE than disabling the page file altogether. The ideal place is a second, physically different hard disk, or the system drive if there is nothing better. But never on RAM.

I was told that some games and programs will skip to the page file so if you put your page file on the RAM DISK you know its FAST!

I was told that some games and programs will skip to the page file so if you put your page file on the RAM DISK you know its FAST!

Can you explain what that means?

Back in the XP days we wondered why Microsoft didn't design a system to take care of this Ram thing. Well they answered with Windows 7 taking care of the Ram thing.

XP wasn't as bad as many people think. Actually memory management in XP was very good. Of course Windows 7 is better.

One problem was the misleading information in Task Manager. It wasn't wrong, just mislabeled and thus misinterpreted.
I am speaking of the graphs labeled "PF Usage" and "Pagefile usage" which actually referred to the commit charge. Many computer professionals didn't understand this. I saw one forum thread where a number of "experts" were stumbling over themselves trying to explain the apparent behavior, but never understanding what they were seeing. The designers of XP were seriously maligned, all over a mislabeled graph. This was by no means an isolated incident. Task Manager often confused rather than informed.

NT4, Windows 2000, and XP all had a graph showing the commit charge but labeled otherwise. The graph was finally done away with in Vista. It really wasn't that important anyway.