October 18th, 2003, 10:47 AM
serial ata raid
How does raid work with serial ata hard drives? ...the same?
October 18th, 2003, 10:57 AM
I would imagine, why would it be any different?
October 18th, 2003, 05:07 PM
Serial ATA, from what I've read, allows much faster read/write times because Windows reads 2 80GB drives as 1 160GB drive.
All the odd bits are written to one drive, the even the other. This allows read/write at twice what a normal HD can.
If your a big gamer or do a lot of graphics stuff, this can really pay off. On the server side, better off to go with mirroring so if one drive bits the dust, you have the other one still running.
October 18th, 2003, 08:33 PM
You can only mirror with normal ata hard drives?
October 18th, 2003, 09:33 PM
No, RAID is a way to use multiple disks in as a single array of disks. It works with UDMA drives, SATA drives, SCSI drives, and so on. How it works in each case doesn't matter much from the use perspective, just assume that SATA RAID is the same as PATA RAID.
And as a side note, data is broken into "stripes" as the smallest chunk. An average stripe size is about 64k, though it can vary quite a bit. If you have a large file, it'll split it up into 64k chunks and write each stripe to each drive, depending on how RAID was setup. You can get varied performance depending on use by varying the stripe size.
October 23rd, 2003, 10:10 AM
The way the data is broken up actually depends on which RAID level you use. RAID 0 used blocks but there is no fault tolerence so it is usually not the best option. In RAID 2 (as stated earlier) the data is striped at the bit level across the disks with one of the 3(or more) drives used to store parity information. In RAID 3 the data is striped in bytes rather than bits and in RAID 4 the data is striped in blocks(similar to 0 but with fault tolerence). Both RAID 3 and 4 also use a parity disk. There are also other less common levels of RAID that could do the striping differently.
Last edited by ianstar; October 23rd, 2003 at 10:15 AM.
October 23rd, 2003, 12:25 PM
In short, no. There's too much overhead to do anything at the bit, or even byte level. Maybe it has happened at some point in history, but in modern times, there's RAID 0, 1, and 5, and various combinations of them. The entry level RAID that comes on consumer motherboards tends to only support levels 0, 1, and 0+1.