not getting 1Gb/s with SRW2008

[net tech]

I have 2 Vista (Ultimate & Pro) and 1 XP (Pro) computers connected to a Linksys SRW2008 switch (all computers connect at 1Gb/s  speed) When I start a transfer of a big file (over 500mb) I am only getting 13.8MB/s (which is 96Mb/s) between Vista systems and 25MB/s when I am transferring from or to XP system.

SRW2008 has been reset to factory defaults, but made no difference with the transfer speeds.

What should be blamed for slow transfer speeds?

[Leo Laohoo]

Firstly, some desktop computers (CPU and HDD speed) could not support true 1Gb transfer.  They may be able to support >100mbps transfer (hence the need for a Gig interface).

Secondly, just because a switch port (Linksys, Cisco or otherwise) sports Gig interface does not mean it will truely support 1Gb.

This is a falacy and used predominantly by sales staff trying to "con" you.  Caveat emptor

Just to let you know, there are 1Gb switches which do support 1Gb transfer but not with a Linksys brand.

[net tech]

I forgot to mention that my Ultimate pc was running media center, which was causing the slowdown. As soon as I close MCE i get 1Gb transfer speeds over the network. I also found a registry change that I can apply to my MCE computer to make transfers faster while MCE is running.

[net tech]

http://support.microsoft.com/kb/948066

[Peter Paluch]

Leo,

You are correct about mostly anything but I personally find myself a bit pondering about your statement that Linksys (but I don't actually care for the particular vendor) switches, although having 1Gbps ports, may not really provide that switching speed.

I would not say a word if we were talking about routers because the low-end routers are implemented as software routers, and the CPU+bus+OS bottleneck is clear here. However, with switches, I believe that this is a different issue. Because of hardware-based forwarding process in switches, I do not believe that even the cheapest switch is unable to provide two ports with their full speed. Agreed, the aggregate traffic (if all ports are fully loaded) may exceed the switching matrix capacity, but with only two ports out of N ports communicating, I am pretty sure that the switching hardware simply must be able to take care of that on line rate, and this should hold even for the most inferior switches made today.

Best regards,

Peter

[net tech]

I was able to achieve 1Gb speeds by changing  NetworkThrottlingIndex value in the registry, so the Linksys switch was not the problem