Is my 100 megabit network now a bottleneck ? Should I upgrade to 1GB ?

It takes 1 min 25 seconds to copy 4GB file from one physical drive to another on the same machine. It takes 8 minutes to copy the same file from one machine to another over the 100 megabit network (source and destination drives are very similar hardware wise, both 160 GB Seagate, one SATA, another - ATA 100, same generation), and the network utilization is about 85-90%.

Does it mean the network is a bottleneck ? Will I gain anyting by upgrading to 1 gigabit considering that prices on this equipment are now reasonable ? What is the importance of Gigabit switch supporting Jumbo frames ?

Reply to
John_Doe
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In article , wrote: :It takes 1 min 25 seconds to copy 4GB file from one physical drive to :another on the same machine. It takes 8 minutes to copy the same file :from one machine to another over the 100 megabit network (source and :destination drives are very similar hardware wise, both 160 GB Seagate, :one SATA, another - ATA 100, same generation), and the network :utilization is about 85-90%.

:Does it mean the network is a bottleneck ?

That's about 71.5 megabits/s, which is not terrible for tcp but could be better.

:Will I gain anyting by :upgrading to 1 gigabit considering that prices on this equipment are :now reasonable ?

I suggest that you test your network using ttcp . That will give you an idea of whether the bottleneck is your disk or your network.

You don't happen to mention your operating system or NIC or anything about the architecture of your systems. You also don't happen to mention what tool you are using to do the copy. We don't really have enough information to tell from the given inforrmation where the bottleneck is.

With that data rate, my -suspicion- is that you are starting to hit the limit either of your NIC or of your architecture transfering data to or from the NIC. If it is your NIC, then a different NIC might get you a bit better performance even with everything else the same. If it's the architecture, then going gig won't necessarily help at all.

:What is the importance of Gigabit switch supporting :Jumbo frames ?

That depends greatly on your traffic patterns. Do you have a managed switch now? If so then look at the packet size histograms. If, as is common, most of your packets are < 256 bytes, then jumbo frames aren't going to help very much. If a fair portion of your packets are of maximum size, then jumbo frames could be beneficial.

Jumbo frames are of greatest use when you are often transfering large files. They reduce the overhead of IP transmissions by reducing the number of times the MACs and IPs and TCP sequence numbers and so on need to be transmitted -- by about 60*6*8 bit-times per jumbo frame compared to regular sized frames. That's not very much at all at gigabit speeds, so you have to look at other factors if you are transmitting on a local LAN. Consider the advantages when you have a large latency (many fewer ACKs). Consider too the effects when you have noticable contention for a shared link --- getting 6 times as much data through per instance that you are able to seize the link can be a significant advantage if other devices are usually waiting to transmit...

Reply to
Walter Roberson

I'm getting about 200 megabits utilization on my gigabit network between two relatively modern machines (P4-2.4, SATA drives, integrated Intel gigabit controllers on the FSB, etc.), so you could probably expect to gain something.

Reply to
William P.N. Smith

I will do this.

One computer is 3.6 GHZ P4 with 1 GB of RAM and onboard Broadcom Gigabit network adapter, another - 1 GHZ PIII with Linksys PCI 100 mebabit network card. They are connected through Linksys BEFSR41 configured as a switch.

Is there some kind of test progrmam to find out if onboard Broadcom Gigabit network adapter supports Jumbo Frames ? I couldn't find any info on that on Dell website. I submitted support request but haven't received the answer yet.

Reply to
John_Doe

In article , wrote: :One computer is 3.6 GHZ P4 with 1 GB of RAM and onboard Broadcom :Gigabit network adapter, another - 1 GHZ PIII with Linksys PCI 100 :mebabit network card. They are connected through Linksys BEFSR41 :configured as a switch.

I would look first at the BEFSR41 as being the bottleneck. The BEFSR41 is not designed as a high performance switch.

:Is there some kind of test progrmam to find out if onboard Broadcom :Gigabit network adapter supports Jumbo Frames ?

formatting link
9000 MTU Ethernet

Martin Kuhne mentioned "Broadcom BCM5703 (64-bit) (3Com 3C996B-T ($65), Dell PowerEdge integrated BCM570x NIC, Compaq NC7770) 9k, verified working"

Reply to
Walter Roberson

OK so here is my TTCP results:

PCAUSA Test TCP Utility V2.01.01.07 TCP Receive Test Local Host : xpsr1000

************** Listening...: On port 5001

Accept : TCP

Reply to
John_Doe

OK so here is my TTCP results:

PCAUSA Test TCP Utility V2.01.01.07 TCP Receive Test Local Host : xpsr1000

************** Listening...: On port 5001

Accept : TCP

Reply to
John_Doe
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This is mostly of importance in reducing the per-packet processing at the endpoints, so if one or both endpoints is the bottleneck, jumbos would definitely help.

Anoop

Reply to
anoop

In article , wrote: :OK so here is my TTCP results: :16777216 bytes in 1.41 real seconds = 11603.40 KB/sec +++

:AFAIU this is close to theoretical limit for 100Mbit network. So it :seems that Linksys router is not a bottleneck. Right ?

Correct, that is near the limit. I would suggest running the test for longer (e.g., increase the number of buffers) so as to reduce round-off effects and start-up effects.

You can get a direct readout in megabits/s with one of the ttcp options; on unix it would be -f m .

As a point of comparison, I get 90-91 Mbit/s between two non-Intel server systems with Tigon 3 cards in them, that are being limited by the 100 Mbit switch they are connected to.

Reply to
Walter Roberson

The first one will definately handle over 100 megabits (I have one machine in that class, and it does ~200 megabits doing Windows file copies). The second one is more dicey. You could always spend the $100 on a new card for the second machine and a gigabit switch and see what happens...

Reply to
William P.N. Smith

yes, i think so!!! if you have enough money you should do it. i did it a month ago and it works much better than the one with 100mbpersecond!!!! greetings |blackhawk.ATS| (Return to Castle Wolfenstein: Enemy Territory) schrieb im Newsbeitrag news: snipped-for-privacy@f14g2000cwb.googlegroups.com...

Reply to
ErwinWieser

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