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mkelly21

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Help with slow Gigabit Home network

Hello,

Wonder if anyone can help with this rather (now) annoying issue

I've just upgraded the cabling in my house to CAT6 and purchased a Netgear GS605 10/100/1000 hub....i've got a Dell GX260 with built-in Intel gig NIC. I also purchased a Negear GA311 for my other PC

I've been testing my LAN speeds and have noticed that I am only acheiving about 200Mbps.... although my calculations could be incorrect (see below)

I've downloaded NETCPS to ensure that I am testing just network and not disk I/O.... NetCPS has come back with

---> CPS   30493696.00  KPS:  29779.00   MPS:   29.08

I assume that I take 29.08 * 8 =   232.64Mbps

Which speed should I be expecting as 200Mbps sounds like 100mb full duplexed.....

Both NIC's are set to 1000Mbps

Cheers

Mark
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Rob Williams
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When complete, did you have the network cabling certified? Network cabling that is poorly terminated, near sources of noise such as power lines, kinks, etc. can drastically reduce network performance. Unlike a telephone simple connectivity over the wire is not enough. Is there any chance you can do a test between 2 PC's and the switch, using factory made patch cables as a comparison.
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mkelly21

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Thanks for the quick response....

Yes, I've tried connecting with factory made CAT 6 cables, to eliminate this. I've also tried connecting machine to machine to bypass the hub and still I get poor performance.

what are the specs of the other pc? things like the harddrives, bus speed, processor and memory speed can all affect how fast the data flies. A turd of a computer with a gig card in it probably isn't going to perform at 100%.    
Have you tried another method, such as simply copying a large file. I appreciate this may not be as accurate. I am not familiar with the application but tried it here on a certified 100mbps network with an HP switch and I get 10. MPS. Not being familiar with the app, and I don't see a detailed explanation, but I am not sure MPS = MBps or if it is correct. For example I get an average of 10.9 MPS, but I also get "104857600 Kb transferred in 9.2 seconds". Doing the math.
104857600 Kb/9.2 sec = 11397565 Kb/sec = 11398 Mbps = 1425 MBps (approx) which is also not correct

QCheck is a similar application with a graphical interface, and well respected. I haven't compared the results on this network but you might want to give it a try:
http://www.ixiacom.com/products/performance_applications/pa_display.php?skey=pa_q_check
The machines that I'm using are.... a P4 2.6 with 1GB RAM and a 40GB Hard Disk running Windows Media Center 2005, the other is a PIII 800mhz with 512mb RAM running Windows 2003 Server SP1 so yes, not the quickest of boxes and hard drive and motherboards will be a limiting factor. Thats why I was using NETCPS because apparently it just tests the NIC and takes disk I/O out of the equation.

I have downloaded and installed QCheck and that reports 333.334Mbps between the two machines....

I have tested QCheck on another network which is running at 100mb, and that reports 94.116mb between two machines... so can I trust it's results?
Also... copying a file which is 2.2GB from machine to machine on the gigabit network takes approx 3 mins.....
There are lot of factors that throw of any test applications results but I have always felt QCheck was well within 10-20% accurate. So the results of your multiple tests show something is definitely out of whack. You have bypassed the wiring and switch so it is looking like a network adapter problem. Only suggestions I have are make sure you have the latest drivers (if so possibly re-install existing drivers), or try adding a high quality network adapter like an Intel or 3Com. Is yours a Realtek by any chance?
Rob, errrrmmm... yep mine is a realtek... it's a reconditioned NetGear GA311 but when I went to install it on a Windows 2003 server it appears that netgear don't support the drivers so I downloaded some realtek ones for it.

However, i've just connected my work laptop which has a broadcom Xtreme 1gb NIC to the P4 Dell machine via a CAT6 machine to machine connection and Qcheck is reporting 333.334Mbps as before...both machines have latest drivers.

Wonder if I have just reached the limits of gigabit for now?
>>"Wonder if I have just reached the limits of gigabit for now?"
Good question. I am not a "hardware guy" but intrigued by your dilemma I did some reading. There are an unbelievable number of limiting factors which can easily limit you to 250Mbps or less. Several reviews I read suggested that a Realtek card with a standard PCI card may not get over 200Mbps, PCI Express cards have higher expectations, and some other brands have somewhat better performance. Some switches state that their switches have a 400Mbps tested maximum throughput. Other factors are wiring, RAM, processor speed, Bus speed and even the operating system, only Win2000 ans XP can reach the high performance speeds.
I am afraid none of that tells you if you have reached your limit or if you have a problem. You might want to post a question in the hardware forum asking what you might expect as a maximum throughput.
--Rob
Intel conducted a test in 1999 for the Gigabit ethernet. Their test result shows the full Gigabit bandwidth can only be achieved by implementing the 66MHz 64bit PCI bus, as well as use CPU and memory that fast enough not causing bottleneck effect.

OK, here are some thoughts.  I don't think this will advance the cause but maybe someone will spark off of one of these...

I'm wondering about your direct-connection experiment.  According to Joe Chang, two GigE NIC connected with a regular-old Ethernet cross-over cable *should* drop to 100 Mbps mode.  Review his article here:

  http://www.sql-server-performance.com/jc_gigabit.asp

The diagrams and explanation at this page look about right:

  http://logout.sh/computers/net/gigabit/

I don't know why you'd see 333Mbps if the crossover cable isn't working right, though - maybe you aren't really?  Or maybe you already have a proper GigE CrossOver cable?  Or maybe the ports are all AutoMDX and they're using the Cat6 straight cable as a crossover?  Hmmm...

Another tidbit - Cat6 really isn't required for GigE, and that's per the IEEE 802.3ab standard.  The cabling needed for 1000Base-TX is Cat5 or Cat5e UTP.  Cat6 may not hurt - but then again it might: just for grins, try an older Cat5 or Cat5e set of cables.  Get good ones - *no* knots, kinks, staple holes, footprints, teeth marks, etc... :-)
As I said before,you need a 64 bit 66 mhz bus in order to acheive near gigabit speed levels.
What you are getting is about right for a 32 bit 33mhz PCI bus.

See:

http://www.cs.uni.edu/~gray/gig-over-copper/gig-over-copper.html#NetGear%20GA302T|outline
IT should also be noted that home networking speed are in the same class as car gas mileage numbers.  :-)

The quoted ones are for perfect conditions in a lab somewhere, where the person is an expert.  

In real life your 2.2gb file in 3 minutes is not too bad, considering all the equipment involved, sending pc, recieving pc, routeretc...
Thanks for all the help.... I've put this down to having a faulty NIC. I've installed a nice Intel 1000 PRO MT and I'm now getting reports of 600mb through QCheck.

Thanks Again

mkelly21
Personally I wouldn't say faulty NIC. You have gone from the bottom of the heap, Realtek, to an excellent card, and can well expect better results. I suspect at this point, as we have all discussed earlier, you other hardware may be the final limitation.
All our NIC's are Intel by choice, even if they are onboard ones, and the Pro MT and S series if PCI.
Thanks for the update,
--Rob
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