SauRoNZA
Honorary Master
Your math is very dodgy it should be half that.
Even then 25MB/s is more like the real world norm.
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5Mbps transfer speed on Wireless-N network. Normal?
- Thread starter DJ...
- Start date
Your math is very dodgy it should be half that.
Even then 25MB/s is more like the real world norm.
How is my math dodgy, if my router says it cam perform at 300mb/s which is 75MB/s why cant it?
Why are people getting 5-7MB/s when they should be getting x10 that?
HavocXphere
Honorary Master
Bru your maths is way off...
300mbps = 37.5 mB/s under ideal conditions (1 byte = 8 bit).
From that you can deduct about 10% for overheads and another 20 percent for wireless being crap. And thats mighty optimistic...because DJ has zero chance of 40mhz & 300mbps unless he is sitting in the stix which he is not. Aside from the 40mhz channel issue, a lot of the n standard gear is 150mbps max anyway....like for example DJ's wifi dongle.
"Good" in my eyes would be: (150mbps /8) *0.7 = 13.125 mB/s. It depend on your location though...if you've got lots of rich neighbors then wifi is going to blow...Quality does not drop in a linear fashion with the level of interference...the quality falls off a cliff. 5-6 is pretty decent and perhaps borderline good depending on neighborhood.
Fail. Serious Maths fail.
300Mbps/8 = 37.5MBps. Then take overhead into consideration and you're left with just over 31MB/s. Then reflection, refraction and diffusion of wireless signal eats the majority of the rest of it.
I'm literally right next to the router...
HavocXphere
Honorary Master
Wrote it before Sauron posted...soz for delay.
SauRoNZA
Honorary Master
A question though from my side which I'm not 100% sure of.
In the 802.11G days it was 54 mbps in TOTAL so send/receive combined.
Is that still the case for 802.11N? Does 300mbps really mean 150/150 or is it 300mbps in either direction as in 300/300?
I generally get about 25MB/s on my 300mbps 802.11N setup which is why I'm wondering.
In the 802.11G days it was 54 mbps in TOTAL so send/receive combined.
Is that still the case for 802.11N? Does 300mbps really mean 150/150 or is it 300mbps in either direction as in 300/300?
I generally get about 25MB/s on my 300mbps 802.11N setup which is why I'm wondering.
Speedster
Honorary Master
Then plug in a lan cable
While I was testing...
Roman4604
Executive Member
The reason why 802.11n wireless is so confusing is because it is such a open variable spec, both from a vendor implementation & adaptive performance perspective. Once you understand how it works, it starts to make a bit more sense.
There are 2 basic building blocks;
20MHz channel with max connection speed of 72Mbps half-duplex without overheads.
40MHz channel with max connection speed of 150Mbps half-duplex without overheads.
The spec allows for channel bonding of same speed channels in either dual, triple or quad configurations.
Vendors are free to implement any permutation of the above, so if for instance they produce a device supporting up to dual 40Mhz channels, they will advertise it at 300Mbps.
Real world performance is obviously less than these ideal maximums. Channels speeds are adaptable and will scale back based on prevailing conditions. Also everything is negotiated between devices and they don't always agree so optimal configuration may not always be used.
There are 2 basic building blocks;
20MHz channel with max connection speed of 72Mbps half-duplex without overheads.
40MHz channel with max connection speed of 150Mbps half-duplex without overheads.
The spec allows for channel bonding of same speed channels in either dual, triple or quad configurations.
Vendors are free to implement any permutation of the above, so if for instance they produce a device supporting up to dual 40Mhz channels, they will advertise it at 300Mbps.
Real world performance is obviously less than these ideal maximums. Channels speeds are adaptable and will scale back based on prevailing conditions. Also everything is negotiated between devices and they don't always agree so optimal configuration may not always be used.
Last edited:
xera
Expert Member
I just tested my router's wireless. It says it has 300Mbps wireless.
When my laptop was right next to the router, the wireless connection said 130Mbps, and it was copying to my laptop at ~10MBps.
When I was at the other end of the house, the wireless connection said 100Mbps, and it was copying to my laptop at ~4-5MBps.
When my laptop was right next to the router, the wireless connection said 130Mbps, and it was copying to my laptop at ~10MBps.
When I was at the other end of the house, the wireless connection said 100Mbps, and it was copying to my laptop at ~4-5MBps.
Roman4604
Executive Member
Probably means adapter & router have negotiated 2 x 20MHz channels stepped down to 65Mbps. Have you checked your adapter driver & router whether they're configured for 40MHz channels?
I changed my wireless setup to this - http://mybroadband.co.za/vb/showthread.php/578969-Help-with-my-wireless-network-setup and got a new laptop with a proper wireless N receiver, and I now connect at the full 300mbps. My wireless transfer speeds are at a stable 11MB/s which is about as good as I could hope for between two walls and 20 metres away...
HavocXphere
Honorary Master
11 = you've still got a 100mbps link somewhere in the mix - router most likely. The manufacturers have this crap thing about selling 300mbps wifi routers with a 100mbps LAN backend...
100mbps /8 = 12.5...minus overheads gets you 11 MB.
That limit is definitely not the walls.
Still given that this n wireless business is all over the show I'd call it a day...if 11MB is sufficient for streaming you cat videos/whatever.