Raid 0 questions (short stroking and striping)

[knowsitall]

say i bought 3 x of these drives

http://www.newegg.com/Product/Product.aspx?Item=N82E16822148445

they are 750gb each

and i test them, and find the sweet spot (the fastest part of the drive) is the first 100gb on each.

so that means in raid 0, i should short stroke 300gb for fast performance.

so i go into my motherboards chipset, setup raid 0. then when i restart i should get another raid setup menu that will say 2,250gb. Now do i set this to 300gb so it is short stroked to the fastest performance?

also, does that mean i will lose the 1950gbs of space?


and my other question is, what exactly is stripeing, and how do u know how much space to use for that?

 

[knowsitall]

think i answered my own question

"Short Stroking Is Powerful

We don’t think that short stroking setups are only interesting for new systems. It makes a lot of sense to look at your existing IT and server infrastructure, and consider the capacities that you actually need. Should performance-sensitive servers
only be using a third or less of storage array capacities, we clearly recommend looking at cutting off some storage space and turning it into increased I/O performance. It may help you to delay hardware upgrades for a few months, which might not be what the hard drive makers want to hear, but is probably a good idea in times of economic difficult"

so i guess to truley short stroke ur drives, u cut off alot of the aditional storage space

source:
last page, last paragraph
http://www.tomshardware.com/reviews/short-stroking-hdd,2157-11.html

 

[sub mesa]

Generally short stroking refers to creating a smaller partition; mostly the C-partition. This way you force all windows stuff required for booting and launching apps, to take place in the fastest spot (first 100GB) of your harddrive.

This technique doesn't change when using RAID0; it just adds the storage space. Now you can short stroke three times as much and gain the same overall benefit from short stroking a single disk alone.

So just create the RAID per normal, then install Windows but don't create one big C partition but a smaller C partition (300GB) and the rest as drive D; so it doesn't get wasted.

You'll get a benefit from short stroking as long as you're not using drive C and D at once; thus if D contains only long-term backups you usually don't access, you would get the most benefit out of short stroking.

 

[foscooter]

^+1 (He is GR8!)

Striping is what you'll be doing in a RAID 0 array. Striping the data across more than 1 drive.

And, like sub mesa said, partition the array (in Windows) as 300MB (fastest portion of each drive x # of drives), and then all the rest, so you can use it, for data/media; I suggest "My Documents, Music, Pictures, Video, Downloads," and the like.

Tests have been made that found that short stroking 4 disks in RAID 0 actually beat an SSD in read/write performance. I forget where I read it, or I'd give you the link.

 

[knowsitall]

so if you allow the slower segment of the hard drive to appear in windows, in the partion "d", is it 100% safe to say that the head wont randomly "wander over there" and slow things down? wouldnt it be safer to allow 300gbs of C to show and the rest just never to appear?

 

[foscooter]

You're thinking right.

The OP asked: "also, does that mean i will lose the 1950gbs of space?"

This way, you won't loose all that extra space. You can use it for "whatever", and yet the head may still bop all over that place, if say, you launched an app stored on the "D:" drive.

But for Windows launchs and program loads, short stroking is a valid option. What you do with the extra space is up to the user.

 

[Chewie]

say i bought 3 x of these drives

http://www.newegg.com/Product/Product.aspx?Item=N82E16822148445

they are 750gb each

and i test them, and find the sweet spot (the fastest part of the drive) is the first 100gb on each.

How do I test my drives to find that sweet spot? I'm buying a second 1TB caviar black to build my first raid0, and I'm wondering what is the fastest part of these drives for my C partition.

 

[sminlal]

How do I test my drives to find that sweet spot? I'm buying a second 1TB caviar black to build my first raid0, and I'm wondering what is the fastest part of these drives for my C partition.

The first part of the drive is always the fastest. If you look at HDTune graphs, they always show a performance curve that looks somewhat like this:

The blue line represents transfer rate, and it's faster for some drives than others, but it always starts out fast and gradually slows down until by the end of the drive it's only about half as fast as at the start.

So where the "sweet spot" is depends on how much space you're willing to waste. The first 10% of the drive is faster than the next 10%, which is faster than the next 10%, and so on.

A reasonable compromise is probably to take the first 1/4 to 1/3 of the drive as being "the fastest".

But don't expect miracles - your system may end up a little bit faster but it's probably not something you'd notice unless you measure it with a stopwatch.

 

[Chewie]

That's what I thought. I'm thinking of a 400gb C partition on a 2tb raid0, with the rest for storing movies and stuff.