100Mbps Ethernet Speed/Efficiency

Jeff Vian jvian10 at charter.net
Tue Apr 6 13:09:08 UTC 2004



WipeOut wrote:

> Ow Mun Heng wrote:
>
>> 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                                           
>>
>>       
>>
>>  
>>
> Without compression and overhead 100Mb/s transtales to about 12.5MB/s..
>
> Of course that is the theoretical maximum..
>
> If you add overhead and contention you will probbaly see an actual 
> transfer of between 60Mb/s and 90Mb/s..
>
> I am not sure how you have managed to see a throughput of 20MB/s on a 
> 100Mb/s link..
>
> Later..
>
I did a test between 2 machines here on a 100Mb switch and got about 
8.2MB/sec tranfer.  That is pretty close to 2/3 the theoretical maximum 
without compression.  Used a 650MB iso image for the test.  Smaller 
files would be different.





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