<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Eddie N:
...so really , if you connected 4 9 gig scsi drives in RAID-0 "formation" (i dont know what to call it), you in theory would have a 36 gig scsi drive 4 times faster than one drive working by itself?<HR></BLOCKQUOTE>
4-each 9GB drives in a RAID-0 array with 1 data stripe would have a 36GB capacity and would have 4 times the read/write throughput of a single 9GB drive. Track-to-track access would be about the same as a single drive though.
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>...how do you go about this? where do you put 4 hard drives or 2 hard drives in a computer or do you keep them externally?<HR></BLOCKQUOTE>
You can mount the drive mechanisms externally or internally. If you go "internal" (inside the CPU chassis), you'll have to make sure you have a large enough power supply to adequately handle the power demands of your motherboard + peripherals AND the drives. Going with an external RAID chassis is probably equally as popular as going with an internal installation.
As for myself, I have 3 SCSI busses in my system and a combination of individual "external" SCSI hard drives that I use for various purposes (booting to Linux, Solaris, Netware, or SCO-UNIX) that are in self-contained drive housings, as well as a pair of 9GB IBM Ultra2 10kRPM SCSI hard drives housed in hot-plug RAID modules. The 2 IBM 9GB Ultra2 drives are configured as a RAID-0 array and work off of a dedicated SCSI RAID channel. These drives can be quickly unplugged from the front of my Supermicro SC-760ATX chassis...
http://www.supermicro.com/PRODUCT/Chassis/sc760A.htm
I will soon be replacing these 2 IBM drives with a pair of Quantum 18GB kRPM Ultra-160 drives, also as a RAID-0 performance array. The RAID adaptor I use is the Adaptec Ultra2 RAIDport iii, which plugs into the motherboard's Ultra2 SCSI channel via a special slot. If I need to, I can also boot from the four other older Wide/Ultra SCSI drives I have in external housings (a pair of 4GB IBM drives and a pair of 2GB Quantum drives) from a different SCSI channel than the RAID channel. I also have a narrow SCSI hard drive (an older Quantum Fireball 1.2 GB) that I use to copy WAV file to for my Akai sampler to utilise via its SCSI port.
Just toget an idea of what I'm talking about when I mention *external* SCSI RAID chassis hardware:
http://www.scsipro.com/
<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>and do you need an adapter card to make it all work?<HR></BLOCKQUOTE>
The *preferred* method is to have a hardware RAID solution -- most popularly done these days with a PCI host controller card. There are also software RAIDs -- like the free RAID-0 and RAID-1 in NT4 and Windows 2000 -- but you can't boot off of a "software RAID" volume. To some, this is not a real problem. Another drawback with software RAID is that it hogs some of your processing power. Doing RAID-3, RAID-4, and RAID-5 as a software RAID is even worse. So, the preferred method is to use dedicated hardware for RAID because these controllers can perform all the I/O handling and RAID parity calculations without taxing the host CPU (like yer Celeron or whatever).
I mentioned my RAID controller above (the Adaptec RAIDport iii), which is a relatively inexpensive SCSI RAID controller designed to work ONLY with motherboards that have a built-in RAIDport slot. If you don't have a RAIDport slot on your Supermicro, Iwill, Asus, Tyan, etc... mobo then you will need a PCI RAID host controllers. A couple of SCSI RAID host controller manufacturers:
http://www.megaraid.com/
http://www.dpt.com/
As a viable alternative, an IDE RAID controller manufacturer:
http://www.3ware.com/index.shtml