Notices

Overclockers Forums > Hardware > CPUs > AMD CPUs
AMD CPUs
Forum Jump

Question about RAID 0 on my Abit KG7 RAID

Post Reply New Thread Subscribe Search this Thread
 
 
Thread Tools
Old 08-31-01, 12:28 PM Thread Starter   #1
dborden
Member



Join Date: Aug 2001

 
Question about RAID 0 on my Abit KG7 RAID


Ok I have to quantum fireball SA 20.5 gigers installed on the Highpoint controller. I set them up to be RAID 0 Stripping. My understanding of this was that they would be identical and the computer would access the data faster becuase it could take half from one drive and half from the other. From what I can tell though it looks like my C: is now 41 gig. Did it just combine both drives under one letter or is my raid working correctly?
dborden is offline   QUOTE Thanks
Old 08-31-01, 12:53 PM   #2
Jon
Just Another Retired Moderator

 
Jon's Avatar 

Join Date: Dec 2000
Location: Lawrenceville, GA

10 Year Badge
 
When running a stripe set with two 20.5GB drives you will have one large disk with a size of 41GB. It uses both disks entirely when using RAID 0.

RAID 1 will show you two separate disks...the main, bootable disk and the disk the mirror is going to so you relatively only have half the disk space available to you.

In short, you're fine...don't worry.

__________________
theHTPC.net
Jon is offline   QUOTE Thanks
Old 08-31-01, 01:09 PM Thread Starter   #3
dborden
Member



Join Date: Aug 2001

 
help


So how am I gettting increased speed if it just combines the two drives? Can you explain it?
dborden is offline   QUOTE Thanks
Old 08-31-01, 01:23 PM   #4
Jon
Just Another Retired Moderator

 
Jon's Avatar 

Join Date: Dec 2000
Location: Lawrenceville, GA

10 Year Badge
 
Say you have a 1 MB file and a RAID 0 setup. The RAID controller will take that 1 MB file and split it into (I'm going to use 64K as an example...4K, 16K and 32K could be used) 64K chunks which are striped SIMULTANEOUSLY across the two disks at the same time. This gives approcimately 75% faster read and write speeds since two hard drives are sharing the load of only one.

It's very simple technology with a great result. 5 of 6 have RAID 0 in my home and they all would if I had the cash.

Spanning a drive is what, I believe, you are thinking of. This is taking 2 or more drives and making one logical drive out of them. Only one disk is used at a time though in a linear fashion. When one disk fills up, the next is used and so on. RAID 0 writes half to one disk and half to another in equivalent stripes simultaneously so you have two mules for one job.

__________________
theHTPC.net
Jon is offline   QUOTE Thanks
Old 08-31-01, 01:24 PM Thread Starter   #5
dborden
Member



Join Date: Aug 2001

 
AHHH! Got it. I knew it was something like that. I thought it mirrored everything and just gabbed half the data from one drive and half the data from the other at the same time.
dborden is offline   QUOTE Thanks
Old 08-31-01, 01:27 PM   #6
theflyingrat
Member

 
theflyingrat's Avatar 

Join Date: Apr 2001
Location: St. Paul, MN, USA

10 Year Badge
 
Since only half the data is written on each drive, there is less waiting for the cylinders to rotate and the read/write head finding sectors. While one hard drive is searching for bits it needs, the other hard drive can already be sending them. AFAIK, the HDD controller will reassemble them for use by the CPU/memory/whatever. There is really a lot less waiting - plus, both drives are able to stream data at the same time.

Assume this: one 20GB hard drive can put out, say, 20 MBps (an estimation). So if it wanted to read a 20MB file, it could take it a full second. If you're reading the same 20MB file off two separate disks, each containing half of the file, each drive will only have to read 10MB of data, roughly cutting the time in half (theoretically). Although real RAID isn't quite this efficient, some setups come pretty close.

What you were thinking about is what's called mirroring. This would read and write the same data to two separate drives, and this type of RAID array (RAID 1), all 20MB need to be taken off each drive in order to get the file, resulting in it taking the full second. This configuration is for redundancy, not performance. It takes no longer or shorter to write/read info in this configuration.

__________________
ASUS P8Z68-V LX ; Core i7-3770K @ 4.3GHz ; 8GB (2x4GB) G.Skill Sniper DDR3-1600 ; ZeroTherm ZT-10D ; Sapphire Radeon HD 7950 ; Samsung 830 256GB + 840 EVO 250GB ; Rosewill HIVE-550 ; Windows 7 Ultimate

2005 Kawasaki Z750S | 2011 Kawasaki ZX-6R | 2008 Yamaha WR250X
theflyingrat is offline   QUOTE Thanks
Old 08-31-01, 01:31 PM   #7
Jon
Just Another Retired Moderator

 
Jon's Avatar 

Join Date: Dec 2000
Location: Lawrenceville, GA

10 Year Badge
 
Mirroring is RAID 1. You can also do a RAID 0+1.

RAID 1 consists of at least two drives and whatever is written to the main drive is also written to the second drive...IN WHOLE. It just makes a mirror copy but perfromance is that of a single disk since only one disk is your actual active system disk.

RAID 0+1 would be having a RAID 0 array and then another RAID 0 array that is a mirror of it. You get the speed of RAID and the redundancy of RAID 1. This takes at least 4 disks of equal stripe set. i.e. 2 X 20GB=40GB stripe + 2 X 20GB=40GB mirrored stripe.

__________________
theHTPC.net
Jon is offline   QUOTE Thanks

Post Reply New Thread Subscribe


Overclockers Forums > Hardware > CPUs > AMD CPUs
AMD CPUs
Forum Jump

Thread Tools Search this Thread
Search this Thread:

Advanced Search


Mobile Skin
All times are GMT -5. The time now is 11:20 AM.
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
You can add these icons by updating your profile information to include your Heatware ID, Benching Profile ID or your Folding/SETI profile ID. Edit your profile!
X

Welcome to Overclockers.com

Create your username to jump into the discussion!

New members like you have made this the best community on the Internet since 1998!


(4 digit year)

Why Join Us?

  • Share experience
  • Max out your hardware
  • Best forum members anywhere
  • Customized forum experience

Already a member?