Help with wireless large file transfer speeds...

roadie

roadie

roadie

Soldato
Joined
22 May 2003
Posts
2,884
Location
Wiltshire
Hey guys,

I have a wireless network set up in my flat which comprises of

- Bufalo WZR-HP-G300NH router. This is a wireless N 300Mbps, gigabit LAN part which is using wireless channels 1 & 5, which appear to be the least congested according to inssider.
- desktop connected via gigabit LAN.
- notebook connected via wireless and showing 300Mbps in connection status.
- there are also other things connected to the network like phones, XBOX and flatmate's PC.

When moving large files like movies from my desktop to my laptop I only see transfer speeds of about 7 megabytes a second, so transferring a ~2Gb file takes a while. This is below my expectations of wireless N transfer speeds!

Does anyone have any suggestions of how to speed things up if possible?

Thanks
 
7MB/s is about 60Mbit throughput, which is likely as good as you'll get. You could try turning on jumbo frames on the wired side which might speed that bit up, but you wont get a hell of a lot more out of your wifi. Wifi just isn't designed to lump large amounts of data about, it's far better at handling multiple low bandwidth data streams. So you could maybe try using multiple sessions to move the data, but if it's a single file you're stuck with what you've got.
Even a very decent 300N router with decent client adapter in perfect signal will struggle to top 10-12MB/s real world throughput.
Also bear in mind wireless is a broadcast multiaccess media, so transmission time on the air is shared among all devices connected. Other devices will also reduce your throughput.
 
300Mbps is the absolute maximum possible throughput of Wireless N given some impossible circumstances so generally we always get significantly less speed than this. Even with the laptop sitting inside the router (if that were possible) you still wouldn't get full speed.

Move the laptop closer to the router.

Reduce other 2.4/5ghz radio sources.

Wire the two together with an ethernet cable.
 
OK thanks for the suggestions guys. I'll try jumbo frames if that's not already on. I don't think there's much better I can do in terms of hardware or with how the router and laptop are positioned.

Maybe 5Ghz is the next step, but I don't use the network for large transfers often, so it's not imperative.
 
Jumbo frames / 5GHz won't do anything for you. I expect that your laptop only has an N 150 card, which is why you only see speeds of approx 60-70 Mb/s. This is because the 150Mb/s etc comes from the signalling rate, however the way that the wifi protocol works means it can only spend around half the time actually sending payload data, the rest it is either listening to make sure the airwaves are clear so it can send or waiting to receive acknowledgement of safe receipt from the receiving wireless station.

You'll never get great speeds out of WiFi, even the Latest N 450 (sometimes call themselves 700 if they are dual band) AP's will only manage around 200Mb/s actual throughput best case.

What I did was pick up a gigabit express card, so I just plug in when I want to do a large transfer quickly on my laptop, It works well and I get around 800Mb/s throughput.
 
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The wireless card is the Intel one linked in my signature, which should do 300Mbps. The router is set at this and 40Mhz, and the laptop reports being connected at 300mbps.

Could the low speed be down to all the other routers in the vicinity?
 
roadie said:
The wireless card is the Intel one linked in my signature, which should do 300Mbps. The router is set at this and 40Mhz, and the laptop reports being connected at 300mbps.

Could the low speed be down to all the other routers in the vicinity?
Click to expand...

IF it reports that it's running at 300mbit then I doubt it. Interference from other routers would degrade the signal, which would cause a lower connection rate, which it should report.

Is there anything else connected to the same SSID?
 
It's 300Mbit half duplex, so max speed one way will be 150Mbit, then you have to factor in overheads etc, so you'd see around 130Mbit on a good 300Mbit connection.

I though 802.11n negotiates the speed anyway, so 300Mbit is maximum, and this lowers depending on obviously a fair few factors? I could be wrong though.
 
Maybe consider a powerline connection, it was suggested to me and it certainly solved my problem
 
Skidilliplop said:
IF it reports that it's running at 300mbit then I doubt it. Interference from other routers would degrade the signal, which would cause a lower connection rate, which it should report.

Is there anything else connected to the same SSID?
Click to expand...
There are a few things hooked up to the router, as per my OP. XBOX360 via wireless (although this is not on when transferring files) a couple of desktop PCs (one doing the transfer) and possibly a mobile phone. I wouldn't have thought it would be anything that would affect throughput much though?
 
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