100Mbps Ethernet Speed/Efficiency

[Ow Mun Heng]

Hi Guys,

I'm wondering what's the maximum sustained transfer rate
that one can experience when using a 100Mbps link? 

Is there any way that I can determine what's the bottleneck?
FYI, I'm using iftop.

Transferring files between 2 PCs, (laptop and Desktop)
I see like up to 20MB/s. 

Could this # be limited due to my slow HD? 4200rpm which
hdparm -t (or is it -T) gives ~26MB/s

1mbps = 1024/8 bits = 1 MB/s (I know there's a conversion
but I'm forgetful)


Cheers,                                                 
Mun Heng, Ow