about TCP transmission of many packets problem

[peaceziz]

hi

i m a newbie about TCP.I made some experiments and found something that i couldnt
answer who anyone knows about how TCP works...please suggest me

the experiment
Multi thread sender sent data 1024 byte 10~5 times,10~6 times, 10~7 times
via long distance network to receiver and measure bit rate of transmission
from packet size 0 to 1024*10~5,6,7 byte

** the data size was separated to each thread for example 1024*10~5 by
2 threads
0 to 512*10~5 is thread 1
512*10~5 to 1024*10~5 is thread 2

the result
10~5 times :
- each thread, bit rate tends to increase but got small percentage increase
in the much larger of data size
- many threads have used, the result of bit rate is quite slow down

10~6 times : as same as 10~5

10~7 times :
- some threads of bit rates tend to increase but some threads tend to decrease
- many threads have used, the result of bit rate is quite slow down

Questions
when data sent 10~7 times why the bit rate tends to slow down?? does it relate about
the thread problem?

Thanks in advance