Allocation size on disk format for FSX

[jlaine]

Hi,

I am following the guide for setting up a new system for FSX and have the Windows XP Pro (x64) set up on a gen 1 raptor 150M drive, and followed the list to the letter.

I now have my second drive a new gen 2 raptor 300M drive and was wondering what would be the best allocation size for the format using disk management.  

Should I just use default unit size or pick something else?

Thanks,

John L.

[NickN]

If you do not have 3rd party disk software like Partition Magic or Acronis Disk Director then the best you can do is the DEFAULT of 4K or 4096

If you have one of the tools I mentioned you can format the drive in NTFS @ 64K clusters which will significantly cut down on fragmentation and help perf

You can NOT format a Windows OS drive or ANY drive that has a Windows Page File on it to anything other than 4K

[jlaine]

Nick,

Thanks for the info.  I went and purchased the Acronis Disk Director and will be using this to format my FSX drive at NTFS and 64K clusters.  Not sure but the default Windows XP Professional x64 Disk manager looked like it could also format the drive at NTFS 64K but this software looks like I can use it to back up my partitions so if I need to go back to the initial known good setup of my system I can do that.

Thanks,

John L

[NickN]

[quote]Nick,

Thanks for the info.

[Gypsy_Baron]

If you do not have 3rd party disk software like Partition Magic or Acronis Disk Director then the best you can do is the DEFAULT of 4K or 4096

If you have one of the tools I mentioned you can format the drive in NTFS @ 64K clusters which will significantly cut down on fragmentation and help perf

You can NOT format a Windows OS drive or ANY drive that has a Windows Page File on it to anything other than 4K

I have used the "Disk Management" feature contained in the WinXP Pro "Computer Management" function
to format several of my volumes with cluster sizes other than 4K.
And I have one small partition with a 2K cluster size that contains a
pagefile. My C: drive is 4K but all my others are generally not.

   Paul

[NickN]

Paul

You may want to do some research on that

1. Moving the page file nets absolutely nothing in performance with modern home/game systems unless they are being used as a server in which the admin has correctly ascertained performance from user workstation requests in which memory of the server may be better optimized by placing the page file on a different volume, and, that volume is faster or equal to the OS partition.

None the less any access of a mechanical volume page file kills perf, period. A user will NEVER, EVER access that file, nor will that page file size or location have any affect (positive or negative) on Windows or system performance unless the system runs out of available physical memory

What you are doing if that page in on a every day HDD solution is a throw-back to Windows98 and ME from years ago when memory amounts averaged 128-512 in very expensive systems and no longer presents any value in most modern, correctly configured systems.

Network Servers and engineering systems however may be different if they are not 64bit and have very large amounts of PM available to them. A home user that is running 2GB and less will also see the memory used up in a app like FSX.

In those cases adding more memory is a much better option than a remote page file, or, if not possible due to the max memory already in use, a SAS/SCSI, RAID or in modern systems SSD will provide the best solution for a remote page file and those volumes should always be allocated to 4K, with exception of the RAID array which allocation can be calculated based on the number of drives in the array.




2. There must be a minimum page file on the OS drive or diagnostics are not possible in the event of a crash and it must be a 4K allocation due to #3.


3. Windows VM Management allocates memory in 4K pages. Even MS states qute clearly the page file set on a separate volume which is not allocated to 4K is not wise after XP was updated.

4. Since WindowsXP SP2 no Windows install can be loaded onto partition with a allocation size of greater than 4K which was designed into Windows from SP2 forward and which was partially done to keep people from making the mistake of installing the OS and page to a file allocation of anything greater than 4K which is in line with how the VM system allocates.

Windows will refuse to boot after attempting to install on any volume greater than 4K



The system only needs a page file for diagnostics and program boot allocation when the system memory is well above the users max use. Some programs demand a page file be present when they are booted, most do not. Turning the page file completely off can be done but only after the proper assessment of the system use with applications. It is still wise to leave a small page on the OS drive in the event of a crash so a minimum dump may occur. In a 64bit OS for file servers it is possible to

[NickN]

I just emailed Redmond to get a confirmation on this. Although I do understand the VM system I also like to be sure what I post is correct.

The only thing I posted above which was not quite right is the remote page file volume allocation size

It can be placed on a volume other than 4K however here is skinny directly from the horses mouth

Hi Nick,

I agree with what you said about page file use. It has no bearing on system or operating system perf unless PM is exhausted.

I do wish to point out that although we frown on any page file other than 4K located on another volume, it can be done. The only part of the file that must be 4K is one located on the volume which the operating system resides. By default Windows will seek the largest page file location and write to that area first ignoring a smaller file on the mother volume.

However allocating 2K on that page volume will fragment that file extensively effectively degrading its performance rapidly while in use. If anything you would want that to be greater than 4K, not less. The only volume which would benefit from less than a 4K allocation would be a page file on a multivolume array.

[Gypsy_Baron]

Nick,

Thanks for those details!

Paul ( doing some rearranging now.... )

[NickN]

Nick,

Thanks for those details!

Paul ( doing some rearranging now.... )

Glad I could help Paul

I have gotten a lot of information from you about scenery and inner workings of the sim from your travels in the application... its about time I was able to repay the favor

[CaptainCrunch81]

Does the Allocation size of 64k apply when using Vista 64?

And could you explain a bit about why/how allocation size can increase performance of FSX?

Edit* Also i am not finding allot to support using a second HDD for Programs and increased performance?

Thank you in advance

x2Edit* @NickN
Cant express how much you've helped me in getting a flyable and visually stunning FSX that runs "SM00TH" and id personally like to thank you for all your tireless work and amazing insights you've given so many, all the while just trying to help us all have a pleasurable time flying FSX  :D

[CaptainCrunch81]

Be great if i could get any advice/answers to the above, as id like to try a full install of FSX on my second hard drive.

[NickN]

It has nothing to do with 'FSX Performance' directly.. it has to do with keeping the disk from fragmenting and it also places more data per cluster on the disk, effectively reducing overhead in mechanical drive action to locate data in flie calls


It does however reduce the amount of disk available to the system. How much depends on how large the drive. In example, after formatting to 64K allocation a 300GB drive may only show 280GB, or slightly less


Its effect is minor in the grand scheme of CPU and memory speed, the key however with success in a peformance computer is: every little bit helps and adds up

[CaptainCrunch81]

It has nothing to do with 'FSX Performance' directly.. it has to do with keeping the disk from fragmenting and it also places more date per cluster on the disk, effectively reducing overhead in mechanical drive action to locate data in flie calls


It does however reduce the amount of disk available to the system. How much depends on how large the drive. In example, after formatting to 64K allocation a 300GB drive may only show 280GB, or slightly less

Great thank you, going to give it a try then  :)


Its effect is minor in the grand scheme of CPU and memory speed, the key however with success in a peformance computer is: every little bit helps and adds up

[Stuart Holmes]

Am I correct in thinking then, that I should install my sim on a seperate drive from the OS?

If so, would that include addons (Traffic/Mesh/Aircraft etc.)?

Thanks,

Stuart