RAID and SCSI are completely different things.
RAID = Redundant Array of Independent Disks.
SCSI = Small Computer System Interface.
SCSI is the type of interface that exists on the physical hard drive for connecting it to a host device. The host, be it a computer or a RAID would need to also support the SCSI interface.
RAID is a cluster of hard drives which work together as a storage system. RAID could use any type of interface, including SCSI.
SATA and SCSI
SCSI uses a parellel communication chain and SAS uses serial Point to Point communication
Most SCSI cards have both internal and external connectors. I don't believe that software will know the difference between a device hooked up externally and one hooked up internally.
this is a parent director of FAQ for scsi.. might have to search abit but your answer may be there. http://www.kuci.uci.edu/~ustor/faqs/scsifaq/
single ended scsi is a method of transmitting electrical signals over wires. one wire carries a varying voltage that represent a signal, while other wire is connected to a ground. single emded scsi cables are of 6m-1.3m long. Differential scsi is a method of transmitting information electrically by means of 2 complementary signal pairs sent on 2 separate wires.
to connect storage devices such as hard disk drives to a PC
Brief introduction about Hardware RAIDThe hardware-based system manages the RAID subsystem independently from the host and presents to the host only a single disk per RAID array.An example of a Hardware RAID device would be one that connects to a SCSI controller and presents the RAID arrays as a single SCSI drive. An external RAID system moves all RAID handling "intelligence" into a controller located in the external disk subsystem. The whole subsystem is connected to the host via a normal SCSI controller and appears to the host as a single disk.RAID controllers also come in the form of cards that act like a SCSI controller to the operating system but handle all of the actual drive communications themselves. In these cases, you plug the drives into the RAID controller just like you would a SCSI controller, but then you add them to the RAID controller's configuration, and the operating system never knows the difference.Brief introduction about Software RAIDSoftware RAID implements the various RAID levels in the kernel disk (block device) code. It offers the cheapest possible solution, as expensive disk controller cards or hot-swap chassis are not required. Software RAID also works with cheaper IDE disks as well as SCSI disks. With today's fast CPUs, Software RAID performance can excel against Hardware RAID.Difference between hardware raid and software raidObviously, hardware RAID is pricier compared to software RAID, due to the extra hardware that you need to purchase. The hardware is typically expensive, and adds a substantial amount to the cost of the whole system.On the flip side, the cheap software RAID can impair the host computer, which may result in poor performance. This is because it needs to process the data before it is written to disk, to determine where each piece of data should go.The controller in a hardware RAID handles these operations, so that the host processor does not have to. The host processor will simply write the data, just like in a normal hard drive.Tips: The performance hit taken by the system can vary a lot, depending on what type of RAID array you have in use. It could be very minimal, as with the case of a JBOD array. Or it can be quite substantial, especially with stripping and mirroring on multiple disks.Hardware RAID offers better reliability compared to software RAID. A software RAID can be prone to data corruption, due to the fault of the RAID software or driver that is being used. A software RAID can also be affected if the host computer is heavily loaded. Heavy processing can cause some pieces of data to be delayed by a small amount of time. These delays can add up, and negate the benefits of the RAID array to some degree.
oh sure,deffanetly connected both oh HDD in same pc, still configure function are different. first time formated the SCSI hard disk.then setup windows and another IDE formated over here and then SCSI's jumper put-up and put-in the IDE'S jumper and the restart the computer. Not only you can have a SCSi and IDE in the same computer but you can now use an IDE drive on a SCSI controller with proper adaptor http://www.addonics.com/products/io/ Most standard PC can have up to 4 IDE devices. You can use an Adaptec IDE RAID controller (like the 1210sa) and add 4 more in a single PC. Or you can use a SCSI adapter with IDE drives and SCSI to IDE converts to have up to 32 drives in a single computer (if you can fit them) Basically, all of the new low cost RAID boxes are made with SCSI to IDE converter using a SCSI controller. Now there is a difference in MTBF. The SCSI will last longer and work harder... as for speed the difference is not much anymore. For half the price and double the capacity, the IDE is still a deal (with the price of the SCSI to IDE adaptor) Ex 73GB SCSI $300 to $400 200GB IDE $120 As for installing it all depends on your system and OS. Depending if you need the SCSI to boot or just be a data drive. For ex when installing as a boot drive under win2000 you will need the driver on a floppy disk. At start up of the install press F6 so the driver will be loaded at the proper time in the installation.... Depending also if you are installing a RAID there will be a special bios setup (in the SCSI card) to set to mount the RAID. Hope this helps Yes
Historically, hda was used for IDE drives and SDA was used for SCSI drives. Today, regardless of physical interface, all drives are treated as SCSI devices.
The wide SCSI-2 uses a wider data path & emdash;16 bit rather than the normal 8 bit & emdash; for the same 10 Mbps. Combining both fast and wide can, in theory, reach 20 Mbps.
cards that fit into a PC using PCI slotsthe most and frequent devices for pci slots are: modems, sound cards, graphic cards, network cards, usb cards, ..., etc.
Either you have some of your hardware doesn't work properly or you have very specifice equipment which requires drivers like SCSI RAID, SATA RAID and so on.