Xp Dynamic Disks, how it works, not necessarily development


I do not know if this applies to this group, but have not received any
responses from the normal Win Xp newsgroups, and I am hoping someone here
may know the answer.

I have 6 old Ultra Wide SCSI hard drives; each drive takes 10 hours to
format and verify. I would like to place the drives in a rAID 0
configuration using WinXp’s dynamic disk option.

My question deals with the buffer segments in the drives. Each of these
drives can have the buffer divided into 3 to 16 segments. I believe this
deals with how WinXp handles the data stream to the drives. Does Xp say,
ok I have 18.1 MB/s to write, then divides by 6 and sends equal data to
each, or does Xp just write an arbitrary amount to each drive and hope the
write speed is enough ~ some sort of circular queue?

These drives are only for video capture. The average write speed I need
is 18.1 MB/s for 3 hours. To complicate the issue, I can place the drives
on up to 3 different SCSI channels; two channels are available on an
Adaptec 2940u2w, and one channel on an Adaptec 39160.

What is the best configuration for striping? Two drives per channel
across 3 channels, three drives on 2 channels, or just place all six on 1
channel? What about the buffer segments?

I guess everything boils down to, how does Xp handle dynamic disks? I
appreciate any help. Thank you,


Drive Specs:

Formatted Capacity per drive is 44 GBs.
Most space I am willing to use approximately 220 GBs.

For 5 drives, with 3 buffer segments, my write speed is about 12 MB/s

RPM: 5,400 RPMs

Average Write 14.2 ms
Single track Write 2.3 ms
Full stroke Write 28.2 ms

Synchronous transfer rate for SCSI Fast-20 (Ultra SCSI)
5-40 Mbytes/sec.

Data Transfer to/from disk/buffer
Min: 124985344 bits/sec = 14.899 MB/s

Buffer: 4096 Kbytes
Usable: 3442 Kbytes

Each drive is a Seagate ST446452W (6 digit)