Wireless access to NAS drive - speed question.

[Hanslow]

Hi All,

Just after an idea of projected speeds with a wireless NAS drive. I'll tell you my setup, give you a filesize, and ask for how fast you think it should be. I think it's running slow, but would like to hear theoretical figures.

I've got a NAS drive RJ45 cabled into the back of my DG834G 54Mbps router which lives downstairs. The machine I've done the file transfer test on is upstairs. The signal strength on my netgear monitor is 6 or 7 blobs (fluctuates) out of 8. The wireless is WEP encrypted (not all my devices support WPA ), SSID hidden, MAC filtered.

The NAS drive has a 7200 rpm drive in it, 16MB cache, access time around 9ms.

How long do you think it should take to transfer a 6MB file from the desktop to the network storage. Would be interested to see your workings out in arriving at figures and any quoted information web pages. I know how long it took last night, which I thought was slow, but would like to hear people's musings before publishing actual figures and opening the debate on why it's slow (if indeed it is).

Cheers

Steve

[aldi]

Wild guess, 5-10 secs over wireless?

[bogie]

ok - so you have a 54Mbps router, that gives you at best, in same room, about 18-20Mbps of real throughput. So Id say you were probably getting at best 10-15Mbps or 1 to 1.8MB/s. You should be able to transfer a 6MB file in about 4-5secs depending on how you do it (copy/paste in windows or FTP etc will be different due to protocol overhead)

re the NAS drive - well it depends on model and protocol it uses...but if its connecting at 100Mbps then your bottleneck should be the wireless side...be careful if its really a SAN type drive and/or its mirrored as you may end up with less than half the throughput you think you should have....

If you want to speed things up on the wireless side then get a 108MBps (Netgear DG834PN) or 270Mbps (DG834N) wireless router........

[road2ruin]

bogie said:

ok - so you have a 54Mbps router, that gives you at best, in same room, about 18-20Mbps of real throughput. So Id say you were probably getting at best 10-15Mbps or 1 to 1.8MB/s. You should be able to transfer a 6MB file in about 4-5secs depending on how you do it (copy/paste in windows or FTP etc will be different due to protocol overhead)

re the NAS drive - well it depends on model and protocol it uses...but if its connecting at 100Mbps then your bottleneck should be the wireless side...be careful if its really a SAN type drive and/or its mirrored as you may end up with less than half the throughput you think you should have....

If you want to speed things up on the wireless side then get a 108MBps (Netgear DG834PN) or 270Mbps (DG834N) wireless router........

I would say 4-5 secs was a bit optomistic. Given the time it takes for windows to asses the file and make the calculations before transfer and the potential packet loss with a 6MB file I would say nearer 10-12 secs. Anyway, not a huge amount of time.

[Hanslow]

Thanks

It certainly looks slow then

It took 45 seconds (ran the copy test twice - about same time each go) to copy the 6MB file.

The drive in question is a Maxtor one reviewed here. More details on it available on the links at the bottom of that page.

There certainly appears to some slow overhead on the file transfer. Now I do have antivirus running (AVG) and my firewall, but the firewall is open to local network traffic.

The question is, how do I trace down the bottle neck in the system? I'd tried copying a larger file from my laptop (also 54 Mbit/s wireless) next to the router with max strength signal, and it was showing similar slow behaviour.

I know there is an overhead with the encryption, so that could be a first test (although I'm not going to run without WEP, even if it isn't that secure). Are there any tools out there that could help, or could any of you hazard a guess at things to try?

Thanks again

[aldi]

Turn wireless off, plug the lappy directly into the router at 100meg and try it again to prove that wireless is the issue. If it is first job might be to update the firmware on the router and drivers on the lappys.

[Hanslow]

One other thing that just occurred to me. My router is still operating in b&g mode, i.e. 11Mbps and 54Mbps, would this bring down the network speed if the only devices connected are all 54Mpbs? It only supports 11Mbps still as I have an old laptop in the garage that is running my old 11Mbps PCMCIA card.

Will give that a go tonight aldi, thanks

Edited by Hanslow on Tuesday 10th October 12:21

[bogie]

running dual mode does hurt it a bit...but only a few % ...its more likely to be a range/interference thing ...the utility in windows only shows what data rate you are connected at not what throughput you are actually getting (which can change on the fly)

id do as above - try it wired to start with and then you will know if its the wireless slowing it down.

[aldi]

Good idea about the 11b, allthough 45 seconds is a bit slow even for 11b! Definatley worth trying sticking it on g-only and trying it again though.

[Hanslow]

ok, will give that a go too. Just remembered that the missus' Nintendo DS works on 11b, so I doubt I'll be able to get away with it permanently

[xiphias]

A 7200rpm hdd with 16mb cache will probably push out 45-60 mBytes/sec - so anywhere between about 350mbits and 500mbits. Unless you ran it on gigabit or firewire networking, the network will always be the bottleneck. The new 11n wireless is 300mbits, so you might be able to realistically sustain 25-30mbytes a sec out of it. Over my 54mb/s network with similar signal strength, I get about 1.8mbytes a sec - with 11b I can only push about 500k/s. Wireless is not good for sustained speed.

Have you checked for conflicting wireless networks? If there are any others about on similar channels you may be getting interference. Use Netstumbler to find out.

[Hanslow]

Will do. There is another network nearby, but on weakest signal strength. I can't see that network when downstairs though on the laptop, only upstairs on desktop. I think they are on channel 11, I switched mine all to 6 when setting it up to help try and avoid interference.

Will do some more fiddling tonight with all the given advice. I'd be happy with 1MB/s if I could get to that level

[bogie]

the draft 802.11n at 300Mbps gives at best 140-50Mbps real throughput so about 17MB/s

[Hanslow]

Well couple of quick tests later. Plugging the NAS drive directly into the laptop gives me blisteringly fast speeds (in comparison to wireless).

I also tried pinging the NAS drive from a command prompt in windows over wireless, and it averaged out at 1ms, so the ping appears to be reaching the drive (and reporting back) very quickly. Maybe it's a windows overhead? Tried disabling anti virus and that didn't help at all.

Back to more toying and playing.....

Edited by Hanslow on Tuesday 10th October 20:49