home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Eagles Nest BBS 1
/
Eagles_Nest_Mac_Collection_Disc_1.TOAST
/
Special Hardware
/
TimeDrive
/
TimeDrive.rsrc
/
TEXT_129.txt
< prev
next >
Wrap
Text File
|
1991-12-11
|
2KB
|
34 lines
This program creates a temporary contiguous scratch file.
It then executes single large block reads and writes,
measuring the time and converting to Kilobytes per Second.
Seeks are restricted to a single volume (partition) on a
drive. A volume that is smaller than the total drive will
yield noticeably smaller seek times than the drive specification.
(This is another advantage of partitioning hard drives.)
NOTE: Total time for a disk transfer is:
T = Seek Time + Latency + Data size/transfer speed
Latency is the time for data to rotate under the heads.
(On average, this is 1/2 the disk revolution time).
Average seek times are measured by reading 200 random
locations within the selected volume.
Maximum seek times are measured by reading the first
and last location within the selected volume.
Data Transfer Speed measures how fast data is transferred
between your drive and the Mac once the drive gets there.
(transfer times vary depending on the drive/Mac combination)
Simulated System measures how fast a sequence of randomly
selected, yet typical, disk transfers take. The transfers
invlove a small number of single block requests (system
resources) folowed by a number of 1-32 block requests
(application requests). The number reported, the "effective
transfer rate," is lower than read/write rates since seek
and latency times are included in the calculation.
BONUS: The data read during Read Transfer rate measurements
is checked against the known random data written. This
thoroughly tests the reliability of storing and retrieving data
on the selected volume.