Gigabit Networking

[Vertimus]

I am planning to move my POS realtek 8319 cards (which disconnects more often than not) to gigabit. I've heard the intel pro/1000 MT cards are pretty nice. I can alos pick them up for under $25. However, i have some questions:

Assuming I am using linux,

What speeds should I expect? What are the bottlenecks?

If the MTU size is a bottleneck, can I change it?

I've heard smb is slow. What filesharing system should i use instead?

I'm looking for a 8-port switch. What should I get and why? Also if the MTU size is a bottleneck, can I hack the MTU size on this switch?

I have a 10/100 wireless router which is connected to the internet. Would connecting a crossover cable from a port on the gigabit switch to a port on the wireless router work? What should I set the gatway to on the clients with gigabit?

TIA

 

[JackMDS]

Originally posted by: VertimusPOS realtek 8319 cards.

LOL, you just made 95% of the None Pro Network users in the world Felling Sh***y about thier system.:shocked:

Link to: Giga and Peer to Peer Home Networks (Current State at mid 2004).

Link to: The Big Giga Thread

:sun:

 

[Concillian]

I get 25-40 MB/sec transfers from my RAID server (capable of 140 MB/sec reads) to my client machine (which is just a Seagate 7200.7 single drive)

25-30 through samba with a Windows drag and drop of a 3.5 gig file
closer to 35-40 with FTP of the same file.

Fast enough that I don't really worry about it. Jumbo Frames does not help the throughput in this case. I believe my limitation is the client drive write speed. Monitoring the connection from the server side I would see spikes at 60-80 MB/sec, but not sustained, like it would transfer fast, wait, transfer, wait, etc... This seems to fully support the client side write being the limitation. I have not tried with multiple clients, but assume this would push it to a point where server side CPU usage may be an issue and Jumbo Frames may be beneficial.

This with an Intel Pro 66MHz card on the server side and a Realtek wonder chip (built into ASUS a7nx8-E) on the client side. Transfers didn't really seem any better with a real card on the client side.

If you feel like setting it up, NFS will almost certainly be faster.
The SMC 8 port switch seems to be the beest overall deal for a switch that supports Jumbo Frames. If you don't care about Jumbo Frames, cheaper switches can be had. I don't know anything about hacking a non-jumbo compatible switch to use jumbo frames.

For my DSL, I use the built in 3c905 chip (10/100) on the server box (linux) and it functions as a router. You should be able to do what you suggest with your standalone router, though it seems redundant and unnecessary. Gigabit spec requires auto-detect, so you can use a straight through or crossover cable anywhere, it doesn't matter at all.

Unless you have RAID 0 everywhere, your drive write speeds will be the limitation of your transfer rates. In my case, I'm just not sweating the small stuff. I use my RAID 5 array on the server just as if it was another hard drive, and the performance difference is not really noticeable. For more demanding than average use, maybe it's worth worrying about, but in my case, not so much.

 

[ToeJam13]

What speeds should I expect? What are the bottlenecks

Saving you from reading the big thread....

If you're using a GigE card on a legacy 32-bit/33 Mhz PCI bus, expect things to top out around 350-400 Mbps. Same goes for mainboards that use an onboard GigE chip.

If you're using a GigE card on a 64-bit/66 Mhz PCI or PCI-X bus, expect a theoretical max of around 960-980 Mbps. Same goes for mainboards that use an intergrated Northbridge/Southbridge GigE solution. However, real life speeds are going to be slower, since you will encounter CPU speed and HDD speed limitations.

If the MTU size is a bottleneck, can I change it?

Maybe. Your driver will need to support it. According to a 3rd party site, here are a few GigE drivers under Linux which support Jumbo frames:
[*]acenic - Alteon AceNIC, 3Com 3c985, 3Com 3c985B, Netgear GA620,HP, SGI, DEC.
[*]e1000 - Intel gigabit
[*]tg3 - Broadcom gigabit

NVidia also claims Jumbo support with their nForce GB Southbridge. Not much in their documentation on Jumbo support in their Linux drivers.

I've heard smb is slow. What filesharing system should i use instead?

FTP, RCP, HTTP, NFS to name a few.

I'm looking for a 8-port switch. What should I get and why? Also if the MTU size is a bottleneck, can I hack the MTU size on this switch?

First and foremost, you need a NIC or a mainboard GigE solution that supports Jumbo frames. Then you worry about the switch.

Another user commented that they were able to use Jumbo frames with their Netgear GS108. However, Netgear's site says nothing about this. I'd email them first. If good, NewEgg offers it for like $120.

I have a 10/100 wireless router which is connected to the internet. Would connecting a crossover cable from a port on the gigabit switch to a port on the wireless router work?

Yes, this will work. A 1000BaseT switch can negotiate to 100Mbps. I highly suggest that you flip the dip switches on both devices to full-duplex (FDX) for the uplink ports, though. Cheap switches often have problems negotiating duplex and such with each other.

What should I set the gatway to on the clients with gigabit?

If your Internet Router has DHCP enabled, your desktop wiill automatically choose the internal trusted side of the Internet Router as its default gateway as long as you have DHCP enabled.

 

[cmetz]

Vertimus, where can you get Pro/1000MTs for <$25? Please share!

>What speeds should I expect? What are the bottlenecks?

netperf, UDP, Linux 2.6, P4 2.8/875, benchmarked at 817Mb/s.

Real-world file transfer speeds, expect >100Mb/s... 200-300 would be a good target range.

>If the MTU size is a bottleneck, can I change it?

Upping the MTU can help, can hurt. Depends on the OS and hardware involved. Also, many switches can't handle larger frames, but a point-to-point link won't have that problem. Try various MTUs and see what gives you the best performance. (often, MTU=4096 or MTU=8192 gives best)

>I've heard smb is slow. What filesharing system should i use instead?

NFSv3

>I'm looking for a 8-port switch. What should I get and why? Also if the MTU size is
>a bottleneck, can I hack the MTU size on this switch?

Get a SMC SOHO gigabit switch, which folks say can handle jumbo frames (no idea what the limit is). Most cheap switches cannot.

>I have a 10/100 wireless router which is connected to the internet. Would connecting a
>crossover cable from a port on the gigabit switch to a port on the wireless router work?
>What should I set the gatway to on the clients with gigabit?

Should work fine, it'll just be one big happy Ethernet, no IP level changes.