What works better for you & why: parallels using a real partition or a virtual hdd?

virtual hdd or real partition? (ala bootcamp)

  • Total voters
    36
  • Poll closed .
J

jalyst

Hunter
I would think the former if you're a performance nazi but I imagine it could depend, any further thoughts on this?

Incidentally...
I'm using an ext (firewire) hdd as my main system drive (1x 500gb HFSX partition).

My mac mini's internal 2.5' 74.5gb SATA has two partitions:
1 HFSJ (43gb) for general storage/back-up, & 1 NTFS (31.2gb) for bootcamp.

I'm not sure if this is the most optimal config, yet to be determined.

cheers,
jed
 
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Depending on what you need parallels for and how much resources you need. I use visual basic and 2005 sql and mysql on a daily basis for school and it works great. If my build screws up I can just overwrite it very easily with a new copy of my back up so no worries for me. Good luck with your decision but personally I would say go wit the Virtual Drive.
 
I do software development here using VS2005 & a bunch of tools. The optimized setup I use is:

- Main Windows XP image on an expanding 32Gb virtual HD (full install with tools uses around 11Gb)
- Development virtual HDD separate from the Windows HDD, on a 3Gb fixed size image
- An additional 1Gb fixed size virtual HDD that I use when dealing with large files in transit (I tend to manipulate very large files for what I do).

I regularly defragment the volume on which my Parallels files are stored using Coriolis System's iDefrag. This way, I can achieve maximum efficiency without the burden of using a whole HD partition.

The benefit of separating the development HDD from the main windows HDD is that I can keep several separate installs of Windows XP with different / unrelated tools and they all use the same secondary HDD for source code. The additional benefit is that when XP goes down (happened to me once after a Parallels Desktop crash, XP was broken very hard and wouldn't boot anymore, couldn't be repaired by the install CD), you grab the last backed up image of the main OS HDD and you are up and running in 10 minutes, without losing any of your work because it's on a separate image.

Go for virtual HD images. It rocks.
 
Interesting websyndicate, darkone, & fpillet, your feed-back is appreciated has been taken on board.

As far as I can tell....

The only reason they added the ability to mount an existing partition with XP (ala bootcamp) was to cater for lazy people, no?

Is there any inherent performance advantage in accessing a windows install from an entirely separate partition or totally different physical drive?

I can see how it might bring some reliability into the fray i.e. if ones main OSX system gets fried, the XP install on a totally separate partition/disk should be fine.

But I struggle to see how it might 'perform better' e.g. better I/O/s etc.
Any thoughts?
 
The way I see it, the reason Bootcamp-partition support has been implemented is because people asked for it, so as to be able to switch between Bootcamp (when 100% windows work is being done) and Parallels (when they also want to use Mac software).

The primary reason to use Bootcamp is maximum graphics performance (and overall maximum system performance) at the cost of not being running Mac OS X. Granted, better graphics performance is a benefit, but I don't see many advantages over running on virtual HDD mode which gives you much better flexibility (i.e. ability to run several VMs at the same time, easy backup / restore, etc).
 
jalyst said:
Interesting websyndicate, darkone, & fpillet, your feed-back is appreciated has been taken on board.

As far as I can tell....

The only reason they added the ability to mount an existing partition with XP (ala bootcamp) was to cater for lazy people, no?
Click to expand...

No.

Boot Camp allows you to run pure Windows and to give Windows 100% of the platform including full native access to all hardware features. When Parallels allows using the Windows partition for the virtual machine it saves you space on your disk, and you need only one license for Windows and all applications. You need install all your applications one time and can use them either natively in Boot Camp or in Parallels. It is a convenience to maintain a single system with service packs and software installations, and it keeps your system legal by not requiring multiple copies of software to be installed. The EULA's can be pretty nasty about that.
 
yes but what I'm curious to know is:

Is there a significant performance advantage in accessing a windows install from an entirely separate hdd, as opposed to having a virtual hdd on the same physical disk/partition as the OSX system?

Logic would dictate yes, but I'm interested in how this translates in practical terms for various users on this forum. It would of course depend on what each user was wanting to do with their guest XP system.

For instance, someone doing something on their XP system which requires heavy disk usage, 'may' benefit if that high IO/s could be offloaded to a separate hdd

can anyone speak from experience along these lines?

cheers,
jed
 
Im running alot of programming apps like vb 2005 express and vb.net 2003 along with sql and it seems to run fine for me. Yea it not the fastest thing in the world but its fine enought for me. I just like to have the luxury of using OS X at the same time rather than rebooting my computer. Now with 3d support most things should run okay. My build is about i would say 11 to 15 gigs full of what I need.
 
jalyst said:
For instance, someone doing something on their XP system which requires heavy disk usage, 'may' benefit if that high IO/s could be offloaded to a separate hdd
Click to expand...

So far as I know you can put your vm's on any disk installed on your system. I'd not recommend running it on a USB drive - firewire, maybe. I've not tried this so I could be wrong.
 
I think I'm going to stick with my current config:

1x ext (firewire) 3.5' 7200rpm SATA as my main system drive.
It has 1x 500gb HFSX partition.

1x internal 2.5' 5400rpm 74.5gb SATA with two partitions:
a HFSJ (43gb) for back-ups, & a NTFS (31.2gb) for bootcamp.

The internal is rarely read or written to (cept for scheduled backups)
so it's ideal as a dedicated drive for XP in parallels, or bootcamp.

I will of course experiment with some virtual hdd's to see if they're
more reliable/practical in the longer term

Thanks everyone for your input, feel free to add anymore thoughts if you wish.

all the best,
jed
 
hard drive seperate, or shared, or virtual,or how large is in itself of no
consequence,as it all runs thru the same pocessor and ram.
the difference is cpu and ram. if you read the parrallels fine print
you will notice that it only uses one core. i have pretty much
stopped using it as virtual because my music recording software is
cpu / ram intense. not to mention you are limited to 1/2 of your ram to
start with.
so basically you get half of your ram running on a

CORE "1" DUO. so if you are using it for office stuff or
communications or internet , virtual is fine, but if you wan't
it for intense gaming, graphics or professional music software
keep in mind that you will be running 1/2 speed and 1/2 power.

i wish i would have realized it before i wasted my 80 bucks.
boot camp is free, and uses 100% of your system power.
 
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jalyst said:
yes but what I'm curious to know is:

Is there a significant performance advantage in accessing a windows install from an entirely separate hdd, as opposed to having a virtual hdd on the same physical disk/partition as the OSX system?

Logic would dictate yes, but I'm interested in how this translates in practical terms for various users on this forum. It would of course depend on what each user was wanting to do with their guest XP system.

For instance, someone doing something on their XP system which requires heavy disk usage, 'may' benefit if that high IO/s could be offloaded to a separate hdd

can anyone speak from experience along these lines?

cheers,
jed
Click to expand...
Running a VM from a separate physical hard drive almost always offers a performance gain. Disk I/O is typically an OS's main performance bottleneck. OSs are constantly accessing the disk and this process is several orders of magnitude slower than accessing memory. The problem is compounded when both a host and guest OS are competing for access to the same disk, since that's a serial process (although SATA's NCQ does add some intelligence to that equation). When the host and guest reside on separate physical drives they don't have to compete with one another for disk access.

Common sense also applies here, too. Running the host and guest on a single fast drive may offer better performance than running the VM from a slow 2nd drive tethered by a slow bus.

Also, just for the sake of completeness, running a VM from a Boot Camp partition still requires the two OSs to compete for disk access.
 
i would agree if your seperate drive is firewire then you can
reduce the load on the on the main drive, but it is still not going
to compensate for the loss of 1/2 0f your ram and only using one core.
parrallels uses one and leaves the the other for the mac. the whole core2duo
thing is based on 2core interaction. parrallels not only cuts it half, it doesn't allow
them to interact.
in your case mmischke, your 1.66 core2duo 2gig ram 100gig int 40gig ext

is split into this;
with parrallels
TIGER running .83 core 1 "uno" with 1gig ram and 100gig int. hd
and
WINDOWS running .83 core 1 "uno" wth 1gig ram and 40gig ext. hd
with boot camp
either TIGER at full strength
or WINDOWS at full strength

if i'm wrong, please tell me cuz i'm not happy about wasting 80 bucks
 
1pauper1 said:
i would agree if your seperate drive is firewire then you can
reduce the load on the on the main drive, but it is still not going
to compensate for the loss of 1/2 0f your ram and only using one core.
parrallels uses one and leaves the the other for the mac. the whole core2duo
thing is based on 2core interaction. parrallels not only cuts it half, it doesn't allow
them to interact.
in your case mmischke, your 1.66 core2duo 2gig ram 100gig int 40gig ext

is split into this;
with parrallels
TIGER running .83 core 1 "uno" with 1gig ram and 100gig int. hd
and
WINDOWS running .83 core 1 "uno" wth 1gig ram and 40gig ext. hd
with boot camp
either TIGER at full strength
or WINDOWS at full strength

if i'm wrong, please tell me cuz i'm not happy about wasting 80 bucks
Click to expand...

the avg throughput of a hdd is waaay less than even a single core CPU & RAM of this generation, so for most types of uses, the hdd is going to be the limitation long before the cpu/ram is.

There is currently a design flaw with parallels (which will be addressed soon) that causes it to steal more RAM for running guest/s than is absolutely necessary. That's why (depending on the type of mac you're running) 2GB or more is ideal.

I agree it would be cool if they could workout some way to keep the cores working in tandem whist still servicing the host and guest os's. But I'd imagine (I'm far from being in expert in cpu logic programming) this would be very difficult to implement.

How much RAM do you have in total? If it's 1GB or less, I'd strongly recommend getting at least 2GB. In my case the most I can install is 2GB because I have a mac mini, but I have noticed a big difference since upgrading from 1gb.

cheers,
jed
 
Thanks for your input mmishke,
I was thinking along the same lines, just needed some other members thoughts :)

mmischke said:
Also, just for the sake of completeness, running a VM from a Boot Camp partition still requires the two OSs to compete for disk access.
Click to expand...

Of course that's assuming that the bootcamp partition is on the same physical disk -which in my case it's not.

cheers,
jed
 
For performance reasons with some apps, I have to use bootcamp. So when I use Parallels, I use it with the bootcamp partition for the following reasons:

1. Licensing - As mentioned above, Windows may only be installed on one machine at a time, and a VM counting as a separate machine. Most apps may only be installed on two machines at a time, and I like to use the other install on my PC tower (Parallels is on my MBP.)

2. Save storage space - I use Windows on my MBP for several reasons. When I'm at the office, I connect it to an external HD where I have many apps installed. But when I'm on the road, I use Windows for different work that doesn't require those apps. Still, the biggest 2.5" HD around right now is ~200GB, and I'm not going to blow another ~30GB just so I have bootcamp on a partition and Parallels run off an image.

3. Consistency - I don't want to have to run Windows update on both Windows installs, or keep track of two sets of applications. Troubleshooting one install of Windows is a pain enough, I'm not down with double that fun.

The advantages of using images is clear, that's why on my PC I have both virtual server and virtual pc installed and I run multiple VMs. I had one update go bad and totally kill a test server install. I copied over the backup image and tried the update again, it worked fine. (Just for fun I sent the bad image to a few windows geeks to see if they could fix it, just as a challenge. Several weeks later they gave up, so the image really save a lot of time.)

Still, in this case, I use a partition.
 
I voted partition:
1) because the backup software can backup both mac and "pc" partition without copying the all virtual disk all the time
2) because in some network situation, booting in native mode from Bootcamp is the only way to go so far
 
I don't use Bootcamp because it is in perpetual beta unsupported by Apple

I make my back ups manually to external sites on the web or a mac HD

all windows data in shared folders

when paralles is running well with all updates I just clone the VM about once a week

Hugh W
 
Hugh Watkins said:
I don't use Bootcamp because it is in perpetual beta unsupported by Apple Hugh W
Click to expand...


Yeah I don't get that, It's not as if it's a really sophisticated program...

It's simply a very basic partition tool + a program that burns you a CD full of windows drivers for the entire mac range, that's it.

I think its just a way for them to cover their arse

In fact, last time I installed bootcamp I didn't even use the bootcamp app.
I simply used the disk utility + windows xp install cd + previously burned mac drivers cd.
 
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