Inconsistent Download Speeds WiFi

[Silicone_Milk]

I have a netgear WNA3100 wireless 300-N USB adapter that I've been using to connect to the internet with for years.
My router is a Linksys WRT300N.

I recently installed a new motherboard and processor on my computer and noticed that browsing the internet was suddenly quite slow. Laggy in minecraft, Quake Live, and even on IRC where I'd fall behind the conversation by a good 3-5 minutes.

I didn't really pay it much attention since I was planning on doing a fresh install of Windows 7 anyways. Well, after I did, the problem didn't go away.

Did a speed test and I consistently get a download speed *slower* than my upload. Not only that, the download speed spikes regularly. It's not a consistent slow speed. It'll jump up to 1.5 or even 3 Mbps then drop right back down to like 0.5 Mbps. (yes, bits per second, not bytes).

I've attached a picture showing the last speed test with the spiking download speed graph.


I've installed the latest drivers for the WNA3100 adapter.
I've tried using it in USB 2.0 and USB 3.0 ports.
While testing the 3.0 ports, I've disabled, and enabled power management with no difference.

Updated my motherboard drivers.

I've restarted my modem and router. No changes.

Changed wireless settings on router to:
Network Mode - Wireless-N Only
Radio Band - Wide 40 MHz Channel
Wide Channel - 3
Standard Channel - 5 (2.432 GHz)

Then, I set everything to auto to let the router figure it out. Nothing noticable happened.

Other computers in the house have a slow speed but are consistent. They don't spike wildly like my computer has been doing.

Any ideas?

[duffman91]

This sounds like interference issues more than anything.

Start out by changing the default channel to 1, 6, or 11 (Industry Standard)
[lvlshot]http://upload.wikimedia.org/wikipedia/c ... LAN%29.svg[/lvlshot]

For instance, if your neighbors all have their WiFi running on Channel 1, there will be plenty of interference. Changing to Channel 11 or 6 will eliminate this possibility (See image above). The discussion as to whether the in-between channels should be used is a Network Engineering topic outside the scope of home use. You should check out this tool: http://www.metageek.net/products/inssider/

Do a scan at home and see what channels is least used.

Out of curiosity, do these spikes coincide with microwave, wireless telephone, or Bluetooth usage? It may sound stupid, but I used to lose internet connectivity any time my neighbor cooked a burrito. I used to live in a densely populated apartment complex.... Good times.

[Silicone_Milk]

There are no other access points being picked up by the tool you've linked.

The spikes happen at any time of day regardless of what devices are running (microwave/phone/bluetooth)

I've screwed with the channels quite a bit thinking it was interference, as you suggested, and the behavior has been the same =\

I'm going to be calling my ISP as the overall download speed has been terrible throughout the house. But since the spiking only happens on my computer I figure there's something strange happening on my end.

My current suspicion is the USB ports on the motherboard. Ever since I swapped to this motherboard my USB webcam suddenly started having severe issues that made it unusable and now my USB based wireless adapter is acting strangely.

[AmIdYfReAk]

Have you scanned to see what wireless networks are around your area?

channel 5 is overlapped with the "standard" channel 6 by over 80% btw.

[Silicone_Milk]

There aren't any near me. Mine is the only wireless network in the area that I'm able to pick up.

I've swapped to several different channels with no change in behavior

[AmIdYfReAk]

Do you still have issues if you're downloading via a wired connection?

[obsidian]

Router firmware update?

[Foo]

Can you try wiring the PC into the router temporarily (even if it means lugging it across the house), just to prove it's a wireless issue?

Once you've done that, you'll be able to target just a few possible factors and that'll help a lot.

[Silicone_Milk]

Happened to find a 50 foot cable laying around.

I still see the spiking behavior BUT I'm getting 19-20 Mbps down speeds now as opposed to 0.5-2

[AmIdYfReAk]

By pass the router, Connect directly to the modem and try it out.

[dghost77]

Wireless is never as good as a wired connection. But I might suspect in this case that the wireless hardware you have may not be too good or is dying. Or like duffman say, there might be interference and not necessarily from another wireless network.