Gigabit Network Decisions

[DrEvilB]

hi there! New to the forum and have been struggling a little bit. Hope people can help!

So here is the lay of the land:
RR Lightning (40M) Internet Cable Modem (Motorola) connects via Cat 6--> Netgear WNDR3700 Wifi router

Router Connects to (With Cat 6):
--> Linksys Gigabit switch (Old)
--> Att microcell
--> Netgear Readynas DUO
--> Main PC​

Linksys Gigabit Switch (Above) connects to via Cat5e and Cat6:
-->Netgear Progear 5 port gigabit switch
--> 2 Apple TV's​

--> SWiM connector for Directv Internet

Netgear Progear 5 port gigabit switch (Above)
--> Apple TV
--> Second PC
--> PoE adapters (Netgear)​

So after that picture here are my questions / issues:

1 Copying from Main PC to Readynas (Before any other switches outside of the wndr3700) seems to be slow. Through Windows Copy I get about 8-12Mb/sec
---Tried MTU settings. No improvement.
---Replaced cabling. no improvement.

2 Sometimes, streaming from other computers and Directv is slow.

All-in-all - I just dont feel like I am getting Gigabit speeds. All copmuters have Gig ethernet cards. I replaced one on my main PC and it did a little, but not a ton.

So here are my questions:

1) If I was to replace all the switches with a Trednet or the Cisco (Any preference?) would that help?
2) If I add a switch after the Wndr Router and just have one ethernet line coming out of the router, into a switch, THEN the readynas adn the computers...would that make a difference?
3) Any other suggestions?
4) Preference on switches?
-- http://www.amazon.com/dp/B001QUA6RA/?tag=snbforums-20
-- http://www.amazon.com/dp/B003BVK7NU/?tag=snbforums-20



Thank you so much for any assistance!

 

[thiggins]

Your network layout is a little hard to follow. Even a scanned, handdrawn diagram would help.

Are the copy speeds you reported Megabits or MegaBytes per second? How are they measured? What is the OS version and processor of the main PC and is it desktop or notebook?

Unless your switch is broken, it's unlikely that buying new switches will help. You can run a quick test by moving the ReadyNAS and PC to the other switches you have.

 

[DrEvilB]

More clarity

I just reread my post and it is more than a little unclear..it is downright confusing . I attached a diagram.

Here is more detail:
1) All computers are running Win 7 Professional 64 Bit
2) Readynas has 2, 2 TB drives
3) Linksys switch is about 4 years old
4) It was a windows copy number, so I believe it is MegaBytes as it is written as MB/Sec...correct?

Not only am I experiencing non-expected speeds for the Readynas, I am also seeing network slowdown when copying files from one computer to another... definitely not what I would expect for a Gigabit LAN. About 8-12 MBytes/sec. I would think I would get a lot more than that as that is only about as that is only about 80 MegaBITs / sec.

So part of me is wondering if I take the Wifi Router and add a Gigabit switch instead of using the router as the switch if that will help? In addition to just upgrading the other switches in general.

 

[thiggins]

Thanks for the diagram. It helped. Yes, Windows reports transfers as MegaBytes/sec.

Again, "upgrading" switches is unlikely to help unless you have a bad switch. Gigabit switches in the sizes you have will pass traffic at wire-speed between all ports.

If you can, it's always best to not daisy-chain switches. Assuming most of the traffic is to/from the ReadyNAS, you want it as few links between it and its users as possible.

Could be one of your devices is flooding the network and slowing traffic or there is a 100 Mbps device causing slowdowns. See When Flow Control is not a Good Thing Candidates are the ATT Microcell and PoE adapter, both of which I assume are 100 Mbps?

I'd move the ReadyNAS and a PC to one of the switches, disconnect the Microcell and second switch (which disconnects the PoE) and run some transfer tests. What is the PoE connecting to anyway?

 

[DrEvilB]

Ok

The PoE is just going to a room that I couldnt get to Via a LAN cable. It is there for my wife to plug into, as the WiFi was too slow (She does a lot of file transfers for her business and remote terminal connections). Over Regular G, it was just too slow. This helped a lot.

So to try the NAS, what if I disconnected everything from the Router, and just left in the Main PC and the NAS. Then do a transfer. That should be a valid test, correct?

I know the Apple TV Gen 2 isnt gigabit ethernet..Im sure the PoE is not as well.

Thank you for the article. I will try the FLOW control settings tonight as well and see what happens. Im afraid I wont be able to change all the ones that are NON Gigabit though...but according to the article, that shouldnt matter?

 

[DrEvilB]

I just took a look at the Main PC and FLOW control is disabled. Interesting enough though..I looked at the Settings on the Card (Realtec Gigabit NIC) and it says connected at 100 Mbps even though the settings have it on 1 Gbps Full Duplex. Now I am scratching my head....

 

[thiggins]

Before you mess with the flow control settings, do the experiment you describe. Basically strip the network down to just NAS and one client and test. If ok, then add elements one at a time.

First thing I'd add back is an Apple TV since you have so many of them. Try your throughput tests between ReadyNAS and PC with and without a stream running to an Apple TV.

I think you mean powerline adapters, not PoE. PoE is power over Ethernet and is used to run power to connected devices like access points over the Ethernet cable.

Note that flow control must be disabled on the transmitting NIC, which would be in the ReadyNAS. I don't think the ReadyNAS exposes a flow control setting.

 

[DrEvilB]

Sorry..yes I meant powerline. Not PoE. I misunderstood. Will let you know what I find out later. Thank you !

 

[DrEvilB]

Ok. So I direct connected teh NAS to my PC and it was the same speed. I upgraded the NAS drivers. Same speed. I upgraded my NIC drivers. Same speed. I am getting about 11-12 MBsec.

Interestingly enough. I am only seeing my NIC on my copmuter show 100Mbps and not Gigabit! I fiddled with it and set it directly to 1000 and still nothing. Just 100. On the router, the lights indicate that the NAS is connected at Gigabit, but everything else (Switch, my PC, etc..) is connected at 100mbps.

I KNOW it used to say gigabit on the PC, but not now. I changed cables and still nothing. All cables are Cat6.

Any suggestions? Sound like there is an error in the NIC in my computer? If it is connected to the Gigabit switch, shouldnt it show it is connected at that speed, or would it go down to the lower 100mbs because of the other devices? I would ecpect it to connect to the switch at gigabit connection?

Thanks... Im now boggled.

 

[00Roush]

Well it looks like you have covered your bases... You already slimmed everything down like Tim suggested, updated your drivers, checked the cables, and tried to force the NIC to gigabit via the driver. Chances are you are right and you have a hardware problem. If possible you might be able to narrow it down by connecting your NIC in the computer to a few different ports on the router and the switch to see if by chance your computer negotiates to gigabit. Anything that is gigabit should negotiate to gigabit regardless of any other devices that are connected to the router/switch. You mentioned your connection from your router and gigabit switch also showed 100 Mbps so I kinda wonder if it might be the router, switch, or cabling.

It is quite possible your NIC is to blame. I have a computer here at home that for some reason won't run at gigabit either. I ended just putting a Intel Pro/1000 PCI NIC in it as I had one laying around.

Let us know how it goes.

00Roush

P.S. Look on the bright side... your throughput with just 100 Mbps connection is quite good at 11-12 MB/sec.

 

[DrEvilB]

Thanks. I am going to go and get a couple NIC cards, and smart switches today (I can return if needed) and just get everything up to date, then go from there. Will try and install it all tonight and see what happens.

I also wonder if it is the router...but I direct connected the PC to the NAS and it still was the same transfer speed, so not positive. I will leave the router as the last piece of the puzzle. I tried several differnt new cables form Monoprice (Cat6) and all functioned the same. I GUESS I could have gotten a bad lot of cables, but I am thinking that is more unlikely in this situation as I am having a more widespread issue.

What speeds do you realistically think I should expect copying to the NAS, or from one gigabit to another? Right now I am at 12MB/sec...

 

[thiggins]

I strongly advise you to move one step at a time. Trying to shotgun a problem like this by changing multiple things at once can get you even more screwed up.

You have a second computer. Why not see if it properly connects at Gigabit speed and then use it for transfer tests to the ReadyNAS?

We tested the Duo back in 2008 with other methods, so it's not easy to say.
You should get around 15 MB/s read and write when transferring large files.

 

[DrEvilB]

The problem with the other computer is that it isnt reaching the NAS at Gigabit as i see it going through the router at 100Mb. I will do one thing at a time, but going to get all the stuff at once to save a trip

Hmm....so the speeds that I am seeing are not that out of line then.

Question for you guys -

For MTU setting (Not sure what it really is) but how do I set that correctly? Any advice there?

I will post when I replace the NIC to see if that cures the situation with the Gb speed.

 

[thiggins]

So neither of your computers, which both have Gigabit NICs can connect to your router at Gigabit speed?

Don't mess with MTU. It can screw you up more than help. You shouldn't have to touch it to get a Gigabit link.

 

[DrEvilB]

Yes, because the other computer is behind the switch that for some reason is only connecting at 100mb. im going to play a little more tonight and see what I can come up with.

 

[00Roush]

What speeds do you realistically think I should expect copying to the NAS, or from one gigabit to another? Right now I am at 12MB/sec...

You should get around 15 MB/s read and write when transferring large files.

Hmm....so the speeds that I am seeing are not that out of line then.

I think you should be able to see a little higher than that... Either way just remember this only applies to read/write speeds from/to the NAS you have. Most computers made within the last 5-6 years can do much higher than that when transferring large files between them over gigabit. With Windows 7 I think most should be able to see 50-60 MB/sec at least. If you happen to have fast hard drives, 100 MB/sec or better is possible on most modern computers. At least in my experience. Then again I seem to have better luck than most.

00Roush

 

[DrEvilB]

Alrighty... So.

1) I did have a bad switch. REPLACED. All computers on that switch now say 1Gb
2) I had a bad NIC in my main PC. REPLACED. Now says 1 Gb
3) I had a bad cable to one copmuter. REPLACED.

NOW...I am all at 1 Gb to and from the NAS. I tried to copy and the time got SLOWER. It went down to 6 MB/sec.

I changed the JUMBO pakt setting to 9014 Bytes and the speed went UP to 20MB/Sec

Finally, it is faster than before...but I feel likeI should be getting 50 like said above. Any other setting changes anyone can think of?

I have an Intel PRO 1000 GT Card installed if it makes any difference.

On the NAS. I have JUMBO frames enabled.


Really Odd... I directly connected the NAs to the PC and got 13MB. I put it all back to the router and I am back up to 20-22MB/sec.

Any thoughts?

 

[00Roush]

WOW! That is crazy you found that many parts that weren't working right. Any power outages in your area lately? I am glad to see you got everything working at 1Gb now but I am surprised it took that many parts to get there.

I should clarify that when I was talking about the possible speeds I was referring to transferring files between two computers. Have you tried transferring a large file between your Main PC and your second PC now that everything is at gigabit?

Most of the time I tell people to not worry about jumbo frames as most computers have plenty of processing power now. In your case though the NAS has limited processing power so using jumbo frames will probably give the best performance as you mentioned. I do recommend though that when using jumbo frames you make sure all computers are set to use jumbo frames for the best performance. Also while it might not be necessary I recommend making the setting change and then restarting the computer. Last thing to mention about jumbo frames is that they are not part of the IEEE 802 standard and therefore can sometimes cause problems. I wouldn't worry too much but I wanted to make sure you were aware of the pluses and minuses of using jumbo frames.

For possible setting changes I recall when reading the review Tim did on the ReadyNAS Duo that there were some possible performance tweaks. Also in the same article Tim linked to a Netgear page about performance tweaks for the ReadyNAS.

Your direct connection result kinda seems weird... It could be possible that jumbo frames are not working correctly with a direct connection. The results when connected to your router look about right. In the Netgear link I gave they show even under the best case scenario for your NAS you might only see 25-30 MB/sec using Vista SP1. So I would say your not doing too bad.

00Roush

 

[thiggins]

I think you should be able to see a little higher than that... Either way just remember this only applies to read/write speeds from/to the NAS you have. Most computers made within the last 5-6 years can do much higher than that when transferring large files between them over gigabit. With Windows 7 I think most should be able to see 50-60 MB/sec at least. If you happen to have fast hard drives, 100 MB/sec or better is possible on most modern computers. At least in my experience. Then again I seem to have better luck than most.

You're not going to get 50+ MB/s from a ReadyNAS Duo. Iozone data reported around 15 MB/s write and 8 MB/s read for 1G file sizes.

 

[thiggins]

1) I did have a bad switch. REPLACED. All computers on that switch now say 1Gb
2) I had a bad NIC in my main PC. REPLACED. Now says 1 Gb
3) I had a bad cable to one copmuter. REPLACED.

That is a lot of bad parts. If your gear is not on UPSes, I'd invest in a few, or at least for the computers and NAS.

NOW...I am all at 1 Gb to and from the NAS. I tried to copy and the time got SLOWER. It went down to 6 MB/sec.

I changed the JUMBO pakt setting to 9014 Bytes and the speed went UP to 20MB/Sec...

As 00Roush said, jumbo frames aren't necessary with current design machines. I stopped tested with jumbo frames because performance was the same or less with than without.

As noted above, 15 MB/write, 8 MB/s read is about what you're going to get from a ReadyNAS Duo. No way will you get 50 MB/s.

I'd say you're done, except maybe for a NAS upgrade if you want higher transfer speeds.