Vista - VHD placement - on faster/same OR slower/different disk ?

10-21-2009

Hello,

I am not sure, if to store VM files

on faster, but the same physical disk as the system,
( on data partition - system one does not have enough space),

SATA II AHCI 7200RPM, 250GB, 50GB system+200GB data,
typical max steady transfer speed 60-80 MB/s)

or on slower, but separate PATA IDE disk 5400RPM,
ATA mode not handy, transfers about 30 MB/s.

Speed speaks for the former, but there can be "fight" over disk
operation between host and guests.
The fight cound be mitigated by NCQ AHCI feature.

What is major opinion ?

--
Poutnik
The best depends on how the best is defined.

10-21-2009

On Wed, 21 Oct 2009 17:35:24 +0200, Poutnik <me@newsgroup> wrote:

Quote:

>Hello,
>
>I am not sure, if to store VM files
>
>on faster, but the same physical disk as the system,
>( on data partition - system one does not have enough space),
>
>SATA II AHCI 7200RPM, 250GB, 50GB system+200GB data,
>typical max steady transfer speed 60-80 MB/s)
>
>or on slower, but separate PATA IDE disk 5400RPM,
>ATA mode not handy, transfers about 30 MB/s.
>
>Speed speaks for the former, but there can be "fight" over disk
>operation between host and guests.
>The fight cound be mitigated by NCQ AHCI feature.
>
>What is major opinion ?

A separate disk. Windows is a pretty disk heavy OS, so when you have
2 Windows OSes using the same disk you see a perf hit.
IMHO, you will probably still see better overall performance, host and
guest, if you move the VM to the 2nd disk.

--
Cheers,
Steve Jain, Virtual Machine MVP
http://vpc.essjae.com/
http://smudj.wordpress.com/

10-21-2009	#1 (permalink)
Poutnik n/a posts	VHD placement - on faster/same OR slower/different disk ? Hello, I am not sure, if to store VM files on faster, but the same physical disk as the system, ( on data partition - system one does not have enough space), SATA II AHCI 7200RPM, 250GB, 50GB system+200GB data, typical max steady transfer speed 60-80 MB/s) or on slower, but separate PATA IDE disk 5400RPM, ATA mode not handy, transfers about 30 MB/s. Speed speaks for the former, but there can be "fight" over disk operation between host and guests. The fight cound be mitigated by NCQ AHCI feature. What is major opinion ? -- Poutnik The best depends on how the best is defined.
My System Specs

10-21-2009	#2 (permalink)
Steve Jain [MVP] n/a posts	Re: VHD placement - on faster/same OR slower/different disk ? On Wed, 21 Oct 2009 17:35:24 +0200, Poutnik <me@newsgroup> wrote: Quote: >Hello, > >I am not sure, if to store VM files > >on faster, but the same physical disk as the system, >( on data partition - system one does not have enough space), > >SATA II AHCI 7200RPM, 250GB, 50GB system+200GB data, >typical max steady transfer speed 60-80 MB/s) > >or on slower, but separate PATA IDE disk 5400RPM, >ATA mode not handy, transfers about 30 MB/s. > >Speed speaks for the former, but there can be "fight" over disk >operation between host and guests. >The fight cound be mitigated by NCQ AHCI feature. > >What is major opinion ? A separate disk. Windows is a pretty disk heavy OS, so when you have 2 Windows OSes using the same disk you see a perf hit. IMHO, you will probably still see better overall performance, host and guest, if you move the VM to the 2nd disk. -- Cheers, Steve Jain, Virtual Machine MVP http://vpc.essjae.com/ http://smudj.wordpress.com/
My System Specs

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