Q on XP Pro and dynamic disks..

[Kartajan]

I was wondering if this plan sounds feasible, and if it would improve performance.

I want to take 2 30G HDD's and make them a dynamic stripe under XP Pro, with my OS there.

All the stuff I care about would be on my 80G.

The questions are:
1. Is there a way to do that during the install process, or do I have to do it as a post install conversion?
2. Would this improve my performance, ala software RAID 0? What level of performance boost can I expect? (I would guess 33%- but I don't know..)

 

[Smilin]

You have one hitch in your plan:
You can't put the OS on a software-striped volume!


Here's a possible plan B for you:

1. Use your 80gig as a primary drive and split it into two partitions: a 50gig and a 30gig.
2. Use the 50gig as C: and install your OS on to it.
3. Add the other two 30 gig drives.
4. Make a software stripe with the two 30gig drives plus the extra 30gig partition. This way you'll have 3 drives churning out raid 0 instead of just two...quite a bit faster... Just be aware your 50 gig drive will be "busy" when your stripe is in use.

Put your pagefile, programs and whatnot on the striped drive and anything you want to be safe on the 50 gig.

You can expect somewhere around 80-90% improvment using a two disk raid 0. I'm not sure about 3 drives, you're not flooding the pci bus yet but I'm hesitant to say you'll get another 50%.

 

[EeyoreX]

You can expect somewhere around 80-90% improvment using a two disk raid 0. I'm not sure about 3 drives, you're not flooding the pci bus yet but I'm hesitant to say you'll get another 50%.

I seriously doubt this much benefit is to be gained from a software RAID arrangement. Seems to me the problem here isn't with the potential to "flood the PCI bus" but to "flood" the CPU and RAM, since the PCI bus isn't controlling the "RAID-ing" of the drives. I could be way off, as I never have used dynamic discs, but it doesn't make sense to me that a software solution would over that much of a performance boost. If so, I should think that more people would use the option, as it as a "freebie" with Windows XP and 2000...

\Dan

 

[spyordie007]

Originally posted by: EeyoreX

You can expect somewhere around 80-90% improvment using a two disk raid 0. I'm not sure about 3 drives, you're not flooding the pci bus yet but I'm hesitant to say you'll get another 50%.

I seriously doubt this much benefit is to be gained from a software RAID arrangement. Seems to me the problem here isn't with the potential to "flood the PCI bus" but to "flood" the CPU and RAM, since the PCI bus isn't controlling the "RAID-ing" of the drives. I could be way off, as I never have used dynamic discs, but it doesn't make sense to me that a software solution would over that much of a performance boost. If so, I should think that more people would use the option, as it as a "freebie" with Windows XP and 2000...

\Dan

Actually I wouldnt be surprised if that's about right on a system that is fast enough to sustain the SW RAID xfur. There are plenty of people who have done this, however they are generally savvy enough to opt for a controller card to put them on rather than running them through the system bus. And of course it would also mean that you would need 3 HDs because (as smilin stated) you cant stripe the drive with the OS on it.

-Spy

 

[Smilin]

Originally posted by: EeyoreX

You can expect somewhere around 80-90% improvment using a two disk raid 0. I'm not sure about 3 drives, you're not flooding the pci bus yet but I'm hesitant to say you'll get another 50%.

I seriously doubt this much benefit is to be gained from a software RAID arrangement. Seems to me the problem here isn't with the potential to "flood the PCI bus" but to "flood" the CPU and RAM, since the PCI bus isn't controlling the "RAID-ing" of the drives. I could be way off, as I never have used dynamic discs, but it doesn't make sense to me that a software solution would over that much of a performance boost. If so, I should think that more people would use the option, as it as a "freebie" with Windows XP and 2000...

\Dan

With Raid 0 there us MUCH to be gained from a software raid arrangement. Nearly all ATA Raid 0/1 cards do NOT have onboard processors. They are pretty much souped up ATA controllers that use YOUR cpu to handle the raid. The only real benifit of using hardware is you can put a boot drive on it. Raid 5 is a different story. If you implement it in software you'll hate life. If you look at the price break on ATA raid cards you won't find a raid 5 one for under $100 bucks. Why? Because they DO have an onboard processor to handle the parity calculations.

And yes, a performance boost of about 80-90% on a dual drive raid 0 over a single drive is about right. Why people don't use this 'freebie' more is beyond me.

 

[Nothinman]

Software RAID 0 and 1 uses almost no CPU, there's no calculations to be done.

The only real benifit of using hardware is you can put a boot drive on it.

Linux software RAID can do this, with a little work.

Why people don't use this 'freebie' more is beyond me.

Because converting to dynamic disks breaks compatibility with just about everything that manges disks other than MS' own tools.

 

[Smilin]

Originally posted by: Nothinman

Linux software RAID can do this, with a little work.

*very* little work relative to microsoft.

You can actually put your OS on software raid 0 in both linux and windows. Under linux it's not a big deal, but under windows you end up with some wierd setup like the OS being on the D: drive. When you throw some sloppily written apps into the mix that use C:\winnt instead of %systemroot% you get trouble from every direction.

Because converting to dynamic disks breaks compatibility with just about everything that manges disks other than MS' own tools.

That could be it. For me it's the whole boot drive thing...it's just such a pain that the couple bucks extra it costs to get an imbedded promise controller on your mobo is worth it.

The part that drives me nuts is that on their workstation OS's they don't allow software mirroring. Grr! Ideally I'd like my basic OS on a mirror and then everything else on a stripe.

Nothinman..you been missing the last couple days? Haven't seen you post much. Maybe you're ducking all the flame wars over the NV35 and the new Athlon eh?

 

[Nothinman]

That could be it. For me it's the whole boot drive thing...it's just such a pain that the couple bucks extra it costs to get an imbedded promise controller on your mobo is worth it.

It wouldn't be worth it for me as my only IDE drive is my data drive, the other 5 are SCSI =)

*very* little work relative to microsoft.

Actually now that I think about it, no work. RedHat's latest installers let you setup md or lvm devices during the install.

The part that drives me nuts is that on their workstation OS's they don't allow software mirroring. Grr! Ideally I'd like my basic OS on a mirror and then everything else on a stripe.

I don't really understand it either, but I guess since they have no way to limit it to the OS drive and they don't want you protecting your data with a workstation OS they don't give you the capability at all.

That's one of many reasons why Windows hasn't been on my workstations for some time.

Nothinman..you been missing the last couple days? Haven't seen you post much. Maybe you're ducking all the flame wars over the NV35 and the new Athlon

Just been busy with other things I guess. I'm not a big gamer so the NV35 doesn't mean much to me and the new Athlons don't mean much because I'm waiting for a dual Opteron board with an AGP slot so I can upgrade my machine that way.

I'm a software guy, I'd much rather fight over why it's dumb to pur your pagefile on a ram drive than why the new nVidia card sucks compared to the new ATI card =)