To page or not to page

[guileman]

What do you guys think about paging file on windows 7 x64?

Is protools 9 running better with or without a page file on every hard drive?

I want to know if i should disable it or let windows configure the page file on every drive.

What are the pros and cons?

Thanks

[MikeLip]

If you've got enough RAM, then running without a page file will speed up your Windows boot time. When windows starts, it loads a bunch of the o/s into RAM them dumps it out to the page file - you can see this if you watch the memory usage when windows starts - its pretty significant, about a gig.

The pagefile by default is a dynamic size on the sys drive (C:). A standard tweak is to set the pagefile to a static size. Set the minimum size and maximum size to the same value and 'Set'. This stops Windows from allocating new space when it needs more pagefile - which takes time. If you have the hdd space, set the minimum and maximum values to the recommended maximum and 'Set'. You only need one pagefile.

I ran with no pagefile (12Gb ram) to speed booting up, but since my last rebuild am running a static pagefile because the boot time isn't a great concern now - my Pro Tools C: needs to be manually chosen in the boot menu now for a bit more security so boot speed is sort of moot to me now. Pro Tools works great both ways.

My pagefile is sitting on a third hdd in my rig as my Pro Tools C: is an SSD.
Never have a pagefile on an SSD. You want to minimize writes to an SSD as its longevity is based on writes. fyi my third hdd is a bootable Windows drive with Internet access - its a WD Green or similar low grade drive, maybe an old 5400rpm. To be honest, apart from storing my pagefile for Pro Tools, this third hdd is really only used to boot into World of Warcraft after hours :)


Mike.

[guileman]

Alright so if i put my page file on the same hard drive as all my sound project.
And if i put the same amount minimum and maximum as my ram (8gb)
So no page file on the c hard drive where windows and all my software are installed, including protools.


Is it good?

[Bill Denton]

Seems to be a bit of confusion here...

While parts of the O/S may end up in the Page File, that is not specifically its purpose.

The purpose of the page file is to allow your system to operate as if it has more memory than the physical memory installed in the computer. Physical memory is utilized in units called "pages". When a given physical memory page is not being accessed very frequently, Windows will write the contents of that physical memory page to the Page File, thereby freeing up the physical memory page for use by other applications, etc.

When a page that has been written to the Page File is needed, another page of physical memory is written to the Page File, while the other page is read from the Page File into the vacated physical memory page.

If you go back to the early days, this whole concept was called "Virtual Memory", and the Page File was often referred to as the "Swap File", since it was used to "swap" pages in and out of physical memory.

One important thing to keep in mind...the reads and writes to/from the Page File are done at a much lower level that the reads/writes done by an application, or by the "main" portion of the operating system, such as a file copy operation in Windows Explorer.

The Page File is written in contiguous units exactly the same size as a memory page. Since it is totally under the control of the operating system, reads and writes can be done without having to deal with problems such as multiple applications trying to read and/or write to the file at the same time.

So, you can see that the Page File is in fact some very slow-access memory. The speed of this slow-access memory is determined by...you guessed it...the performance of the drive on which it is stored. Which means that you would not want to place the Page File on something like a 5400 RPM USB drive, you would want to have it on one of the faster drives in one of the faster configurations in your system. But note that you do not want to put the Page File on the same drive you are using to record audio.

It is generally a good idea to have the Page File, if you use one, on the same drive that holds your operating system, applications, etc...this is normally your C: drive.

So, should you use a Page File? It depends. For audio applications, the best advice is to start out with one, then, if you want to experiment, you can try running without one. If you are running a well-configured, decent-performance system you should get better performance with a Page File, but YMMV.

Handy Hint...if you are going to mess around with your Page File, do it like this. Assuming your Page File is on your C: drive, temporarily move it to another drive. Defragment your C: drive, then move your page file back to the C: drive. This will enable you to avoid having a split Page File. A split Page File results when you increase the size of your Page File, and the new portion cannot be written contiguously with the existing portion. While we are talking a fraction of a gazillionth of a second here, a split page file will not perform as well as does a contiguous one...

[MikeLip]

Don't use your Audio drive for pagefile.

If your C: is a physical hdd (not SSD), then use that for your pagefile. You wont gain much by moving the pagefile off C: and you risk (probably guarantee) errors in Pro Tools due to contention between Windows and ProTools on the Audio drive.

If your C: is an SSD then I'd recommend getting a third physical hdd for the pagefile (say on a Samples drive). If a third drive is not option, then use the SSD for the pagefile and be prepared (C: backups) for it to fail say within a year.

With three physical hdd's you can move your pagefile from C: to the non-audio third hdd (say Samples drive).
If the pagefile is active during normal operation (say you have <4gb or running additional software on your rig on top of pro tools) then moving the pagefile to the third hdd will speed up paging operations.
If your pagefile is not active during normal operations (your RAM is enough and windows is not paging to drive) then the benefit is so marginal I wouldn't bother - you'll speed up win boot time by allowing windows to dump from C: to the third drive rather than from C: to C: - but the benefit is so small with windows boot times being what they are nowadays.

Hope thats clear.

And yes, the maximum pagefile size recommended is 'usually' the amount of ram in your pc. But I say 'usually' with no evidence. When I was running with 6GB ram, win7x64 recommended a max of 9136 - dunno why, but thats what I went with.

Mike.

[MikeLip]

Originally Posted by Bill Denton

Handy Hint...if you are going to mess around with your Page File, do it like this. Assuming your Page File is on your C: drive, temporarily move it to another drive. Defragment your C: drive, then move your page file back to the C: drive. This will enable you to avoid having a split Page File. A split Page File results when you increase the size of your Page File, and the new portion cannot be written contiguously with the existing portion. While we are talking a fraction of a gazillionth of a second here, a split page file will not perform as well as does a contiguous one...

^^^ Very true. Good tip.

[guileman]

Thanks guys, now i have a really good idea of what the page file is.

Thanks

[spenner]

Originally Posted by Bill Denton

It is generally a good idea to have the Page File, if you use one, on the same drive that holds your operating system, applications, etc...this is normally your C: drive.

From all the articles and threads I've read on this topic over the years ^^^^ is what I chose to do.

W7 handles the page file well. I leave it set to system management on the C: drive on both W7 Pro x64 PT9 systems, one with 12G RAM and the other with 8G RAM. My drives are WD Black SATA 6Gb/s 64 MB. Windows boots in seconds and there are no problems with heavy VI sessions. There are no pros or cons. It just works fine for me when set to system management.

[Benoni]

In general, there is no real benefit by disabling your page file. Which by default should only be on the OS drive. No need to enable it for non OS drives. I would set the Min and Max to the same amount. I set mine to 4GB min and max, but it can vary based on other factors.

Here is more info from Mark Russinovich

Some feel having no paging file results in better performance, but in general, having a paging file means Windows can write pages on the modified list (which represent pages that aren’t being accessed actively but have not been saved to disk) out to the paging file, thus making that memory available for more useful purposes (processes or file cache). So while there may be some workloads that perform better with no paging file, in general having one will mean more usable memory being available to the system (never mind that Windows won’t be able to write kernel crash dumps without a paging file sized large enough to hold them).

Configuring a system with lots of RAM to run without pagefile may have either negative or positive perf impact depending on what the system is doing. The general recommendation in this case is to create a reasonably sized pagefile (for example, 4 GB) and increase it if the Paging file\% Usage counter gets close to 100%.

By the way, there are actually 2 separate reasons why pagefiles are necessary.
The first reason is to allow dirty pages that are never (or very rarely) referenced to be moved to disk, freeing up more RAM for other purposes.
The other reason is to enable better use of *virtual* memory, given that physical memory is allocated on demand. Remember that when a process calls VirtualAlloc(MEM_COMMIT) there are no physical pages allocated at this time. Physical pages are only allocated when the app accesses virtual pages for the first time. This is good because it makes committing pages a relatively cheap operation, so apps can commit memory in bigger chunks, without having to worry about each page they may or may not use.
Now, even though committing memory does not allocate physical pages, it still guarantees to the application that reading from/writing to the committed pages will never fail (or deadlock). It might be slow if other physical pages have to be moved to disk in order to make room, but it will eventually succeed.

Originally Posted by Jeff Atwood from Coding Horror

So, if you have a lot of RAM, you don't need a pagefile, right? Not necessarily. When certain applications start, they allocate a huge amount of memory (hundreds of megabytes typically set aside in virtual memory) even though they might not use it. If no pagefile (i.e., virtual memory) is present, a memory-hogging application can quickly use a large chunk of RAM. Even worse, just a few such programs can bring a machine loaded with memory to a halt. Some applications (e.g., Adobe Photoshop) will display warnings on startup if no pagefile is present.

My advice, therefore, is not to disable the pagefile, because Windows will move pages from RAM to the pagefile only when necessary. Furthermore, you gain no performance improvement by turning off the pagefile.

http://www.sevenforums.com/performan...ld-faster.html