Virtual Memory Optimization Guide!

[Adrian Wong]

Originally Posted by SmartDrv

Thanks for the quick response. I hope I didn't come off as being too negative but as I'm sure you understand there are a lot of "tweak" sites around that offer information that either does nothing or that actually hinders performance (i.e. most of those sites that tell you to edit low level memory management parameters)

While I don't see anything in your guide that would hinder performance, I do suggest a section about how changing what physical drive the page file is on is more important to overall performance than how fragmented it is. I imagine your next section will probably go over that mentioning things like how it's best to keep the page file on "fast but less busy" drives and how spanning the page file over multiple physical disks is good in some cases (i.e. SCSI) but bad in others (i.e. over 2 drives on the same IDE channel)

And as I suggest, if you need some more information, check out some of the past threads on the forum I posted. I'm not affiliated with the owners and am not trying to advertise that forum for them, however, there are a lot of smart people (Network Admins, Developers, Engineers, etc) mixed in the crowd. Some like DriverGuru seem to know so much about lower level functions of operating systems that it can make your head spin.

I look forward to your next update!

Hello SmartDrv!

Not a problem. If there's a mistake with my guide, I would like to know about it so that I can improve it. No one's perfect.

ROTFL! You certainly can read my mind!

Actually, I posted a list of methods I will cover in this revision of the guide in the last page of the guide, as well as page 4. There should be two more parts to this guide!

[T8000]

Originally Posted by Viper007Bond

Wow, that's a good idea.

I'm going to try to make mine use like 2 MB of space all of the time though as I should never have to use all of my GB of RAM... right?

You need a page file to run Windows, since a lot of applications expect one. Even if you have more free RAM than total pagefile when running them, some applications cannot run without the page file.

If you have a lot of RAM, using the same size for the pagefile as for the RAM should be OK.

Since todays Harddisks are rather large, I just use a small NTFS partition. Do remember that pagefiles do not like being on partitions with less than 15% free space, so to prevent annoying error messages, make sure to make 15% more space than you plan to use for your pagefile.

I think having a slightly too large pagefile does not have any performance disadvantages over a small one, so you should not try to save a few 100 MB to see how small you can go.

[Chai]

I used to run 384MB of pagefiles only! Obviously it wasn't enough, but Windows will kindly warn you about running low on space allocated for pagefiles. I don't see any potential hazard if you allocated very little space. I wanted to force Windows to use more of my RAM doing this! Obviously that doesn't work!

[Adrian Wong]

Originally Posted by Chai

I used to run 384MB of pagefiles only! Obviously it wasn't enough, but Windows will kindly warn you about running low on space allocated for pagefiles. I don't see any potential hazard if you allocated very little space. I wanted to force Windows to use more of my RAM doing this! Obviously that doesn't work!

There are other ways of doing that.

I think that will be covered in Part 4.

[Protools_Opearator]

Hello!
The guide was very helpful and I can't wait to part 4.,

I have a question regarding an option in XP AntiSpy that called Clean page file on shutdown.,

I wonder if it'll change the postition of permanent pagefile from the outer HD space to the inner?

Thank you,
-Noam

[Adrian Wong]

Originally Posted by Protools_Opearator

Hello!
The guide was very helpful and I can't wait to part 4.,

I have a question regarding an option in XP AntiSpy that called Clean page file on shutdown.,

I wonder if it'll change the postition of permanent pagefile from the outer HD space to the inner?

Thank you,
-Noam

We are posting the third part tonight.

Actually, that option is only for security purpose. If you use it, Windows XP may not recreate the paging file in the original position. Therefore, it may end up split into two or worse.

[Dashken]

The guide has just been updated!

Even today, virtual memory is still very important component of the operating system. No matter how much memory you have, there is always a need for virtual memory. Therefore, its performance is of great importance. Optimizing the virtual memory system will greatly improve the performance of the computer.

Today, we will take an in-depth look at virtual memory, what it really is and how to optimize it! In this edition, we will also take a thorough look at moving the paging file to a different partition as well as the pros and cons of moving it to a different hard disk. Come and check out the definitive Virtual Memory Optimization Guide!

Here are the updates:-

• A thorough look at moving the paging file to a different partition.
• The pros and cons of moving the paging file to a different hard disk.

Link : Virtual Memory Optimization Guide Rev. 4.0!

[Viper007Bond]

Ooo, goody!

[Scarceas]

I realize the guide is not complete, but I was wondering if in part 4 (or
maybe I missed it) you might discuss data localization and virtual memory
performance.

I've read two different arguments on this, and they are somewhat conflicting.

On the one hand is the argument you already provided, regarding a fragmented vs contiguous page file:
http://www.rojakpot.com/default.aspx...ar1=143&var2=0

On the other hand, some have asserted that under Windows XP the paging file,
when left to its default behavior, will store it's pages in close proximity
to other data on the physical disk. So if you're in your "my documents" a
lot, the paging file would store itself near that physical location. The
theory here is that the seeks are much shorter.

I'd like to know how important locality is, and how it fits into the
definitive virtual memory guide.

[Adrian Wong]

Hello Scarceas,

Actually, no. I don't think there will be any discussion of data locality and virtual memory. That's because I don't think Windows XP even bothers about data locality when it comes to creating virtual memory.

AFAIK, Windows XP simply uses the nearest available clusters for the dynamic paging file. In fact, Microsoft states that if you create multiple paging files, Windows XP will favour the partition that is LEAST active. That goes totally against what you claim others are asserting.

If you are interested, read this - http://support.microsoft.com/default...b;en-us;314482

In any case, it doesn't make sense for Windows XP to create the paging file based on spatial locality to work files like your documents. Once opened, Windows keeps the working copy in the Temp folder, not your paging file.

Incidentally, can you give us the link to the sources that mention this spatial data locality feature of the Windows XP paging file?

Thanks!