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mistersmithx
Contributor
Contributor

AHCI drivers for SSD disks in Fusion (Win 7 or XP?)

I have installed a solid state drive (SSD) in my MacBook Pro 2010. It's SATA-III and should be fast. I guess things are faster in OS X, things open in one or two bounces. Nice.
But I mainly wanted it for WIndows work using some GIS apps heavy on the CPU. I have XP and Win 7 (Win 2008 R2) installed on two Boot Camp Partitions. I also have VMWare Fusion 4.1.1.
Apparently Windows needs "AHCI" drivers to fully utilize the speed of a SSD. Does anyone know if making WIndows 2008 R2 use AHCI drivers will interfere with VWMare? Or does VMWare ignore the AHCI and just default to IDE? Also what about XP? In other words will VMware use AHCI and if so, will it be faster, when I'm using Windows XP or 7 in Fusion?
Thanks all.
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keiooz
Enthusiast
Enthusiast

My problem was a bit related as I am also trying to install AHCI on Windows 7, but I don't think it is possible and I can't find any answers in the Internet.

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ChipMcK
Hot Shot
Hot Shot

You are asking about installing the drivers in the bootcamp partition, yes?

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Technogeezer
Immortal
Immortal

I'm assuming that you're not using Bootcamp here.

Hard drives presented to a virtual machine are virtualized SCSI or IDE drives. Virtualized hard disks never see the underlying hardware, rather they are either .vmdk files residing on the Mac's file systems, or a raw disk device file presented through the Mac's file system. In either case, Fusion reads files through the Mac OS to satify I/O to the virtual disks.

From the WIndows virtual machine's point of view, it uses standard SCSI or IDE drivers for its virtual disks. The virtual machine has no access to the physical hardware which the AHCI driver would require. You therefore do not need and probably will not be able to use specialized Windows AHCI SSD drivers in the Windows virtual machine.

You are at the mercy of the Mac OS disk drivers for the behavior and speed of the virtual machine's disk access.

- Paul (Technogeezer)
Editor of the Unofficial Fusion Companion Guides
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mistersmithx
Contributor
Contributor

I am using Boot Camp yes. I like to have the option of rebooting in pure native Windows. It's great to have Windows in Fusion so I can use OS X while waiting for processes to complete sometimes, but it's also nice to boot into native Windows if I need the absolute maximum performance at times.

So if I use Win XP and/or 7 on Boot Camp, but I boot this BootCamp partition into VMWare Fusion 4, will it use AHCI drivers inside of Windows or will it use OS X as the host and will whatever OS X uses control my disk access from Windows inside Fusion to the partitions?  (These are all one partitions on the one SSD I have in my MacBook Pro. Also..I have 10.6.8 which says it is using AHCI to access my drive.)

I have been using Fusion with Windows and noted that it's not much faster. I was reallly, reeeeally hoping an SSD would speed up my use of some intense GIS apps inside Fusion. However, after researching, I am guessing maybe it is because I have not installed AHCI drivers? (XP and 7 are still on IDE).

keeiooz it's very possible to install AHCI drivers on Windows. It's a bit more complicated IF you have already installed Windows but is doable for both on a MacBook Pro. Well, at least for Win 7. For XP it appears best to "slipstream" the drivers into the XP installer so it installs them while installing a fresh XP setup. I do not want to reinstall if at all possible.

Follow the threads I posted... For Win 7 some smart people at MacRumors etc have created a patch that will install them. (The MacRumors thread is the best one).  You have to do a few things first and after the patch, so follow the directions carefully, or there will be serious problems. However, I have not done this yet. But I will, if in fact anyone here knows if AHCI driver installation will increase Fusion XP or 7 performance when running Windows from a Boot Camp partition.

Thanks for any input or comments everyone.

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ChipMcK
Hot Shot
Hot Shot

Apple supplies drivers for the bootcamp environment.

Is not Apple also supplying the disk drivers?

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mistersmithx
Contributor
Contributor

Apple Boot Camp drivers are IDE, not AHCI. AHCI drivers dramatically increase SSD performance.

VMWare drivers are also IDE. My question is, if I install AHCI drivers, will VMWare fusion use them? Or is there way I can force VMware to use the AHCI drivers? In either XP or Win 7?

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continuum
Immortal
Immortal

Installing AHCI driver only makes sense if the system uses a SATA controller.
VMs do not have SATA controllers so you do not need AHCI drivers inside a VM


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ColoradoMarmot
Champion
Champion

If you're that concerned about SSD performance, don't run Boot Camp.  You should then get the full OSX performance bump.

FWIW, I thought that you could only have one Boot Camp partition, and (if you upgrade), note that newer Mac's can't run XP in boot camp at all.

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mistersmithx
Contributor
Contributor

Thanks for all the input everyone, wow this forum is really fast-moving!

So VMs don't have SATA controllers? Hm. I bet they'll add this eventually because, eventually everyone will have SSDs.

Continuum you make a good point...just install directly to a Fusion VM image, vs. using Boot Camp, to take advantage of OS X and its inherent speed with its use of AHCI drivers. Originally, I used Boot Camp for the times I needed performance.

I will try installing Windows straight to a Fusion VM and report back on the change (if any) in performance. If it's fast enough I may ditch Boot Camp. I also like the 100% compatibilty booting natively offers, in case I need it...but the slooow performance of Fusion on Boot Camp is killing me.

dlhotka you can in fact have two partitions with Boot Camp. Google triple booting. It's actually quite easy. FIRST install the old version of WIndows, for example, XP. Then install Win 7, or Vista. It will know an older version of Windows exists. It will point the MBR to boot the newer Windows partition always, but it will offer a menu (BCD) that allows you to choose which version of Windows you want. And it's good to install rEFIt and Easy BCD and Visual BCD as tools to configure and repair this setup. Also, dlhotka, I believe if you ALREADY have an XP installation in Boot Camp it will continue to work in Lion. It's just that Lion won't let you create a fresh XP install...but from what I remember (if I recall right) if it's already there, it will continue to work. I have 10.6.8 so I can not verify this. I will be holding off from updating OS X...there are multiple issues I have with Lion.

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ColoradoMarmot
Champion
Champion

They actually use SCSI controllers - remember, we're talking virtual hardware, not physical.  My experience with Boot Camp/Fusion is that the big performance gain with the former is only in Graphics...disk seems roughly the same.  Thanks for the pointer on triple booting though - I have a collegue who wanted to try that.

On the new HW, Apple no longer provides boot camp drivers (not a Lion thing - a HW thing, early 2011 MBP if I remember right).

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mistersmithx
Contributor
Contributor

In VMWare Settings it says "Hard Disk (IDE)". Aso it says IDE in Windows' Device Manager.

However, should we assume, as someone above noted that VMWare, since it's running on top of OS X, is using OS X AHCI drivers? I don't understand why Windows still runs so slow if that is the case. It's almost as slow as it was with a regular HDD. I wonder if VMWare can use AHCI drivers and if so if it'll speed it up? Because since it's "virtual IDE" or whatever, I presume it still has those IDE limitations, like not being able to use SSD NCQ (Native Command Queuing) and other features that enable SSDs to be fast.

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ColoradoMarmot
Champion
Champion

Runs as slow as a HD?  That's really odd, my VM's run almost as fast as native when I host the file on an SSD.  What version of Fusion did you create the VM in?

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