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Speeding up gigabit home network

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February 12, 2006 12:11:59 AM

Hey guys, I was wondering if anyone might be able to help me out. I have a Gigabit Lan setup at home with 3 computers. They all have gigabit nics that are running at full duplex and they are hooked up to a netgear gs108 8 port gigabit switch.

When transferring files between the 2 computers I can't seem to get anything faster than about 22 mb/sec.

Computers are all at least 3ghz P4's running SATA2 drives with 16mb cache, so I dont think Its the computers that are causing the bottleneck.

Is there any way to speed this up? Anything I should be tweaking in windows or my network settings?

Thanks for your help,

Kai
February 12, 2006 8:39:23 AM

Are you xfering through windows (i.e. drag-and-drop)? You may want to try via ftp was is much leaner. Also, what kind of cable are you using (CAT5, CAT5e, CAT6, etc.)? Did you make them yourself? How far is your longest run? What brand NICs are you using and do they have the most recent driver? Throughput is more than a function of NICs and switches.
February 12, 2006 10:27:59 AM

Yes I am transferring through windows.

I am using homemade cat5e runs, none longer than 50 feet.
The nics are both Marvell Yukon Built-in gigabit nics, and they have the most recent driver.

I guess maybe I'll try hooking everything up with a couple of purchased cat5e cables and see how it goes.
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February 12, 2006 12:21:42 PM

If you made your own cat5e cables and did it correctly that shouldn't be your problem. Make a crossover cable and do a direct connection to two of your machines and test your throughput that way. It should be more or less the same as your disk-to-disk rates on that machine.
February 14, 2006 2:38:15 PM

How are you measuring the transfer rate?

For short (in-room) runs, I doubt cable type will matter much.

You shouldn't need crossover cables since gigabit NICs should auto MDI/MDI-X and make the connection. But graysky has a good suggestion to take the switch out of the equation.
February 18, 2006 7:27:19 PM

You won't be able to go further than 100 Mbps if you do not have a 10/100/1000 network card. If you are connecting through a switch or router, again it needs to support 1000 Mbps.


,,
February 28, 2006 9:48:58 PM

Hopefully someone can help me here or point me in the right direction. My average upload/download speed is 50KB/s. Is this slow? I have a similar setup with 2 Marvell 1000/100/10 nics and an SMC unmanaged switch. Both nics have jumbo frames enabled at 4088 bytes.

Thanks
March 30, 2006 2:18:46 AM

make sure you are using cat6 cables. You should be getting at least 300Mbps on average. I usually get about 30-35% network utilization on large file transfers. Which is about 300-350Mbps.
March 30, 2006 6:44:50 AM

The first thing to clarify, are you saying 22 MB as in Mega BYTES or 22Mb as in Mega bits? How are you measuring?

A 100Mbit connections will theoretically transfer at 12.5 MBytes so a 1000Mbit connection will theoretically transfer at 125 MBytes

Thus if you are saying 22Mbits, it's only 2.7 MB, that's slow even on a 100Mbit network. If it's 22MB, you're still slow on the gigabyte scale. Based on the fact that 22MB won't happen on a 100MBit connection I assume you mean bits. Figure between 20-30% for overhead, gigabit has higher overhead requirments, so maybe 35-55% (I'm sure someone here is better than me at math so jump right in!) And using SMB takes even more overhead than FTP or http transfers. I almost always do large transfers between my systems with ftp since it's so much faster. My network gets around 450 with ftp, around 300-350 like cisco said with SMB.

I'd say if you're equipment is actually handling the traffic properly you should be seeing somewhere from Edit: 150-300 MBits on a gigabit connection.

Cat6 is not needed for gigabit networks, hell cat5e isn't either. I've run plenty of office networks over existing cat5 and get fine speeds (over 200Mbits on older machines). And distance won't be a factor. The "limit" is 300ft, but I've had 100Mbit connections go over 700ft with no problem (don't recommend that with gigabit though). Make sure you don't have the cheapest cable you can get though, that can matter.

The hard drive transfer speed is important, but so is the pci bus, 80MBytes max from that sucker which is still around 600Mbits however. If you have multiple things accessing the pci bus, i.e. the hard drive and the network card both transfering best they can, you've essentially limited both to 40MB or the 300Mbits "happy" number. Use high quality NICS or pci-x nics to get the full speed (I use Intel Pro's almost exclusively). I've got a few machines with PCIe RAID controllers so they work faster than my other machines which only have the PCI 33mhz bus (it is noticable).

One last thing, if ALL the network equipment doesn't support Jumbo Frames, of the same size I might add, stuff won't work worth a darn as packets will just keep dropping. Make sure the SMC supports the same size jumbo's you've set your nics for.

I'm tired and have a headache so if I fudges some numbers don't raz on me too bad :) 
April 3, 2006 6:39:18 PM

Is it a bunch of small files or large files. You may see quite a bit of speed difference between transfering a ton of small files or one large file. I normally get around 26megabytes per second when transfering something like a game install between computers on my network and around 40megabytes per second when transfering disc iso's or divx movies.
April 27, 2006 6:05:52 PM

"You won't be able to go further than 100 Mbps if you do not have a 10/100/1000 network card. If you are connecting through a switch or router, again it needs to support 1000 Mbps. "

-i dont think old timer read the post.......... ANYWAY...I have a 24 port gig switch from netgear..(GS724T) I see a max of 118 MBps upload and around 75 for download...but then again im using homemade cat5e cable...not that it matters that its homemade...Im working on getting some cat6 but untill then those are my benchmarks....Cable is also measure in MHz. The higher the better....
May 5, 2006 4:29:33 PM

Quote:
make sure you are using cat6 cables. You should be getting at least 300Mbps on average. I usually get about 30-35% network utilization on large file transfers. Which is about 300-350Mbps.


dude....your retarded there is no way you can obtain those speeds...Take gigabit meaning 1000 bits per second now divide that into bytes (1024 divided by 8) the theoretical limit of gigabit would be 128 Megabytes per second...
May 9, 2006 4:55:55 AM

Quote:
make sure you are using cat6 cables. You should be getting at least 300Mbps on average. I usually get about 30-35% network utilization on large file transfers. Which is about 300-350Mbps.


dude....your retarded there is no way you can obtain those speeds...Take gigabit meaning 1000 bits per second now divide that into bytes (1024 divided by 8) the theoretical limit of gigabit would be 128 Megabytes per second...

Before you really confuse some people, 1000 bits per second would be 1 kbps, not 1 Gbps. cisco is on the right track, as he is specifying bits per second.

For the sake of clarity, speeds should always be reports in bps, kbps, Mbps, or Gbps (in all cases bits per second, notice the lower case b for bits rather than the upper case B which would mean Bytes)

1 Gbps = 1,000,000,000 bits per second

http://en.wikipedia.org/wiki/Gigabit_per_second
May 9, 2006 3:16:42 PM

correct my bad, but you still should see speeds over 30 MBps :) 
May 30, 2006 1:01:23 AM

Your problem, like mine, is that your switch does not support JUMBO FRAMES. Which is the advantage of Gigabit. (9kb frames)

the only way around this is to buy a better switch.

May I recommend the freaking-amazing-Linksys-SRW2024, which is actually a CISCO switch in disguise, for roughly $500 CAD.

Also, Cat5e should be fine, but try Cat6...

Also, don't forget that the PCI bus is MAX 1gbps, meaning you'll never get that much out of it.

The only way to squeeze 60-80% of true gigabit speeds is to have everything ideal, short cat6 cables with cat6 ends, a NON-BLOCKING gigabit switch, JUMBO FRAME support on all devices in the path (NICS and switch), etc etc.

Also look into "NIC TEAMING" or "NIC BONDING" aka 802.3ad

This is a very cool way to use 2 NICs in tandem to squeeze some more bandwidth.
May 30, 2006 2:02:24 AM

Most of the time, you're limited by the drive speed, not the network speed. Tweek the network all you want, you typically can't exceed single IDE to single IDE transfer speed of around 30 MB/s.

You can test the drive transfer speed by temporarily pulling one of the drives and putting it in the other computer, and transferring between them. Watch out for file cache effects, which can give misleading results.

If you can prove that your drives can do significantly better than this, it's worth looking into further software tweaks and benchmarking the raw networking throughput. Only after this should you seriously consider throwing money at the networking hardware.

Considering that crappy brand PCI NIC's can do 80-90 MB/s raw networking throughput over jumbo frame-free consumer switches with even cat 5 cabling, it's silly to just assume that the problem is the networking and throw more money at it.
May 30, 2006 2:25:41 AM

Reviews here show that most SATA drives can write at 60-80 (or higher) MB/sec... and I believe them...and the original poster (at the top) states that he has some very serious SATA2 16MB Cache drives.

I have tested many several "crappy" gigabit NICs and I find them to be exactly what you paid for; crappy. On my switch wo/ jumbo frames I get about 25MB/sec sustained, but it peaks up to 36MB/sec. Even if you connect them with a cross-over and enable jumboframes, preformance is all over the place. (but it is a noticable preformance increase on BIG files, like DVD images)

What he wants to see is unlikely, you wont ever see true GIGABIT speeds, but there are some ways to maximize network preformance.... buying $30-40 NICs (Intel MT server-class NICS) isn't a big deal. I agree the Linksys SRW2024 is perhaps overkill, but hes spent hundreds (even thousands) on other computer hardware; why spend $250 on a crappy 8port switch when you can get a 24 port NON-BLOCKING, 802.3ad switch for twice the price? :p 

Its more futureproof imo. And it wont loose it's value instantly like other crapy switches; its a CISCO switch and will therefore depreciate only minimally over the next 5 years.

Also - think of the bangin' lan party you can have with a truly "overkill" switch like that... its Non-Blocking with a full 48Gbps backplane, meaning that you'll never bottom it out speed wise...
May 30, 2006 2:41:59 AM

There's a big difference between sythetic drive benchmarks and actual file copy performance.

I have no idea why you're mentioning file sizes in your report of NIC performance. File sizes don't affect networking speed -- file transfer throughput, sure, raw networking, no.

File transfers will also be erratic for their own reasons largely independent of the networking. Using very large files can minimize the impact of such issues and of the system file cache as well.

Do the real tests transferring files, and don't spend money on HW before doing so. OTOH, if it's your money, do what you will. I think I'm done here.
May 30, 2006 2:09:36 PM

I still say getting the best NICs would help. For $30-40 USD it cant really hurt.

Try getting 2 good Intel Pro 1000 MT Server NICs (PWLA8490MT-chipset NICs) and connecting them with a crossover cable; I'm willing to bet the farm you'll see a huge increase in speed over normal NICs connected thru a blocking switch/hub.

If hes got 2 SATA2 16MB drives in a RAID0 on a new p4 setup he SHOULD be able to get more than 25MB/sec...

Make sure your cabelling is Cat5e, not just Cat5. If you can find some cheap Cat6 thats even better.

What I'm gonna do is buy a 5pack of those NICs($130 CAD) and put two in my server, two in my main workstation, and use the NIC Teaming/Bonding/Aggregation feature (802.3ad) to get a nice fat pipe between my two main comps. See if I can't squeeze 50-75% of a gigabit out of it.
May 30, 2006 8:31:19 PM

I think I said it earlier but I use a program called Netmeter...Its a program used to monitor the speed of information going in and out of your computer as well as keeping total amount of data transfered...Anyway Im using an 8mb cache IDE drive and It shows peak upload speed of 118MB/s and peak download at 56MB/s. Using SATA II with 16mb cache should see speeds at least a little bit faster than this.
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