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Infrared

macrumors 68000
Original poster
Mar 28, 2007
1,716
65
Hi, does anyone have any comparisons of disk performance under
OS X and Windows?

The reason I ask: I've come to notice that the sound of disks
being accessed is very different under the two OS varieties*.
So much so, I can recognize the OS in use merely by the sound
of the disk!

So, I'm led to wonder: which OS on a Mac Pro has better disk
read/write speeds?

* - Really rather rough and silly descriptions follow :)

Windows - snow being crunched underfoot
OS X - a spun coin settling on a table
 
It's hard for me to compare, as I use a dedicated disk for windows. But I do notice a difference. I'll listen out for crunched snow / spun coins next time. :) Not sure which sounds worse!
 
It's hard for me to compare, as I use a dedicated disk for windows.

Definitely the way to go for comparisons, though. The performance
for a typical "Boot Camp" partition can be expected to be worse
because of where it is found on the disk.
 
Definitely the way to go for comparisons, though. The performance
for a typical "Boot Camp" partition can be expected to be worse
because of where it is found on the disk.
That, and you don't have to worry about them "playing nice" with one another. :p
 
i have two separate hard drives for each OS.

i have a 500AAKS (Western digital) drive for windows and its only noticeable when transferring large amounts of files.

my original drive in my system was a Seagate ST3500641AS 500gb (seagate barracuda 7200.9 ... and you could hear it almost any time something was being accessed; which seemed to be the case with ANY Segate harddrives in any of macs and as well as using other seagate drives in enclosures.

i recently just cloned and updated the original drive in my macpro to a 500aaks for my OSX drive and now its completely silent even on transferring large files and launching apps, a complete difference compared to the previous drive before.

so i suppose it just depends on the drive you have; seagates have been known to be pretty noisey drives when being accessed.
 
i have two separate hard drives for each OS.

i have a 500AAKS (Western digital) drive for windows and its only noticeable when transferring large amounts of files.

my original drive in my system was a Seagate ST3500641AS 500gb (seagate barracuda 7200.9 ... and you could hear it almost any time something was being accessed; which seemed to be the case with ANY Segate harddrives in any of macs and as well as using other seagate drives in enclosures.

i recently just cloned and updated the original drive in my macpro to a 500aaks for my OSX drive and now its completely silent even on transferring large files and launching apps, a complete difference compared to the previous drive before.

so i suppose it just depends on the drive you have; seagates have been known to be pretty noisey drives when being accessed.

Definitely the OS in my case. I have two identical WD drives. But I've
also had Windows on a Boot Camp partition along with OS X. In that
case, the characteristic drive access noise is there. So it's not a drive
difference that leads to a sound difference.

It is also not necessarily a file system issue. If I run Windows off a
drive in VMware Fusion, it sounds like OS X. Incidentally, as I have
mentioned before, disk performance seems better in Fusion that it
does running natively:

https://forums.macrumors.com/threads/509885/

So, what are we left with? File system structure and layout could be
a factor. But I suspect a bigger factor is the way each OS deals
with disk accesses. E.g., maybe OS X caches more. Or maybe there
is something strange about Apple's BIOS emulation. I only mention
that because there have been problems with it in the past. However,
I appear to have both AHCI and UDMA mode 6 enabled, so that may
be irrelevant.
 
So, what are we left with? File system structure and layout could be
a factor. But I suspect a bigger factor is the way each OS deals
with disk accesses. E.g., maybe OS X caches more. Or maybe there
is something strange about Apple's BIOS emulation. I only mention
that because there have been problems with it in the past. However,
I appear to have both AHCI and UDMA mode 6 enabled, so that may
be irrelevant.
Apple's EFI is different. As I understand it, it's a proprietary version of EFI 1.10. Presumably to implement the hardware lock needed to install OS X. And apparently, it can cause headaches for 3rd party hardware manufacturers. I know it's been an issue with some RAID controllers.

BIOS Emulation may allow the drive to be accessed in a manner more accordant with your drives. They would have had greater levels of testing with BIOS I should hope, compared to Apple's EFI to solve any issues.
 
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