Trying to hit 1Gbps on home LAN, having troubles

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Skillz'n Magic

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Mar 6, 2008
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I'm upgrading my home network and I'm trying to hit as close to 1Gbps as possible. I'm familiar with networking, but this is a little new to me and before I start throwing cash at it I'd like some opinions.

Setup:
Three PC's with onboard gigabit network adapters.
- One supports "jumbo frames" - doesn't specify size
- One supports max 9.5k jumbo frames
- One supports 8000 something size frames

I have a D-Link DGS-2208 switch with jumbo frame support.

Also every room is wired with CAT5e cable to a patch pannel in my network closet.


Testing:
iperf was used for all tests. I also used a 150MB file to do real-world test verification.

Test 1 - I connected the PC's to the switch without enabling jumbo frame support on the NICs and I got about 190Mbps, which is what I expected.

Test 2 - I enabled jumbo frame support on the PC's and tested. Now I got about 350Mbps, this I did not expect. I figured I'd be at least at the 750Mbps range.

Test 3 - Since not all cards supported 9.5k frames I borrowed an Intel Pro 1000 Nic from work and installed that in each one of my PC's and tested. I still only hit 350Mbps. Unfortunately we only had 1 NIC on hand so I couldn't rule out my onboard NIC's completely. But I did rotate the card through all the PC's without hitting higher speeds.

Test 4 - Thinking my patch pannel or wiring was causing the issue I tried connecting the PC's through the switch with 350mhz CAT5e patch cables. I still only hit 350Mbps. Is there a correlation between the 350mhz cables? I can't find anything higher than that.


I'm running out of ideas here. I have three more thoughts on this.

Conclusion
- I need to get two quality NICs to test with. I was thinking of getting two of these: http://www.newegg.com/Product/Product.aspx?Item=N82E16833106121

- I need CAT6?? I didn't think you'd need CAT6 to hit 1Gbps speeds.

- My switch is the problem? Though I've seen people reporting speeds of 750 - 950 Mbps on this same model.



I'd be much appreciative if someone could give me some advice.
 
Most hard drive's average transfer rate is around 70MB/s. That is 560mbps.

If you can setup a RAM drive. *maybe* you can achieve 1gpbs. I'd personally be very happy with 350mbps.
 
how are you transferring the file? ftp would probably be faster than normal windows filesharing.
 
You should replace your nics if you want to get close to true gigabit speeds.
 
Menelmarar said:
Most hard drive's average transfer rate is around 70MB/s. That is 560mbps.

If you can setup a RAM drive. *maybe* you can achieve 1gpbs. I'd personally be very happy with 350mbps.
Click to expand...

Ha-ha brilliant!...That is true, that my hard drive may be limiting me on my server box, it is rather old. I will have to look at the specs on that guy. Can't believe I didn't think of that. :eek:

My deal is that I have a file server that I store everything on. The problem is coming up when I view folders with my photos in them. They photos are about 5MB so it takes an annoyingly long amount of time to open them. Plus I'm using Vista on one of the wired PC's so that doesn't help.

But yeah.....if my HDD is limited to 50MBps average I'm only going to hit 400Mbps (theoretical) max. Which is what I'm getting. Guess I'll have to wait for large SSD's to hit the coveted 1Gbps.


Thanks for the quick replies guys!
 
Jay_oasis said:
You really need decent intel NICs to be honest,.
Click to expand...

+1 to that. The closest I've ever come to 1Gbit/s was with two single-port Intel PRO/1000 PT Server Adapters and a Dell PowerConnect 2748 in the middle. Each run was ~50ft from the wall jack to the patch panel, with 3ft cables from the patch to the switch and 7ft cables from the wall to the systems. If I remember correctly I hit about 875 Mbit/s.

The server NICs aren't really required though as I've done 750-800 Mbit/s on the normal Desktop PT adapters.
 
100% on a 1Gbps?

Not happening

by the time you hit 80%. That switch (regardless if it is a home gig-e switch or enterprise level gig-e switch) will be huffing and puffing.
 
figgie said:
100% on a 1Gbps?

Not happening

by the time you hit 80%. That switch (regardless if it is a home gig-e switch or enterprise level gig-e switch) will be huffing and puffing.
Click to expand...

Correct, I agree with that and that's what I expected. I did think I'd be able to hit higher speeds than 350Mbps, but taking into account my HDD, which I overlooked, 350 now makes much more sense.


A question for those recommending better NIC's - How will that improve transfer speeds if my HDD is the bottleneck?
 
It wont necessarily.

If you want to do some test minus the HDDs, look into iperf
 
Grentz said:
It wont necessarily.

If you want to do some test minus the HDDs, look into iperf
Click to expand...

I have been using iperf and it's giving me 350Mbps which I thought low. However, my file transfer test gave me the same results but that's much more what I expect with the HDD's in the equation. I guess I don't need to hit 800+ Mbps in iperf if I don't get equal real-world results.
 
Which version of iperf, and what options are you using?

Try using iperf verison 1.7:

server: iperf -s
client: iperf -c server -l 64k -t 15 -i 3 -r

Windows file transfers are a whole other kettle of stinky fish, but it makes sense to see what your network can do independent of the drives, and SMB, etc.
 
Its not a limitation of any of the hardware. You are most likely getting very close to 1Gbps. The protocol overhead is the limitation.
 
figgie said:
100% on a 1Gbps?

Not happening

by the time you hit 80%. That switch (regardless if it is a home gig-e switch or enterprise level gig-e switch) will be huffing and puffing.
Click to expand...

Nonsense. Of course you can't hit 100%, but you can get close enough even with consumer gear to call it essentially "wire speed".

F:\tools\bench\iperf>iperf -c 192.168.0.105 -l 64k -t 15 -i 3 -r
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.0.105, TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[796] local 192.168.0.147 port 27083 connected with 192.168.0.105 port 5001
[ ID] Interval Transfer Bandwidth
[796] 0.0- 3.0 sec 348 MBytes 972 Mbits/sec
[796] 3.0- 6.0 sec 346 MBytes 967 Mbits/sec
[796] 6.0- 9.0 sec 345 MBytes 964 Mbits/sec
[796] 9.0-12.0 sec 347 MBytes 970 Mbits/sec
[796] 12.0-15.0 sec 347 MBytes 970 Mbits/sec
[796] 0.0-15.0 sec 1.69 GBytes 968 Mbits/sec
[840] local 192.168.0.147 port 5001 connected with 192.168.0.105 port 1679
[ ID] Interval Transfer Bandwidth
[840] 0.0- 3.0 sec 354 MBytes 991 Mbits/sec
[840] 3.0- 6.0 sec 353 MBytes 987 Mbits/sec
[840] 6.0- 9.0 sec 353 MBytes 987 Mbits/sec
[840] 9.0-12.0 sec 353 MBytes 987 Mbits/sec
[840] 0.0-15.0 sec 1.72 GBytes 987 Mbits/sec
Click to expand...
 
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