How can I fix slow network speeds?

May 27, 2009 4:07 PM

What is making the connection between my two computers so slow?

Computer A runs Windows XP Professional; Computer B runs Windows Vista 32-bit and Windows 7 64-bit. No matter which version of Windows Computer B has running, the connection between the two computers is very slow. A 1GB file taking 80 minutes seems very slow to me. Computer A's XP is pretty much untouched; I've made no network-related changed aside from installing NetBEUI which did nothing. Computer B is also untouched in regards to network settings on both Vista and Windows 7. I use a WRT54GL running Tomato in G mode; both network cards are set to use G mode and are connected at 54mbps with perfect signal strength. Any ideas on how to remedy the slowness?

posted by mithiirym to computers & internet (10 comments total)

How are you pings? Ping one computer. If you truly have a good wireless link you should be getting one or two milliseconds with no lost packets.

If youre getting over 10ms and/or lost packets then you have a crummy connection. The wireless power link really isnt accurate enough to describe the quality of the connection. You can change the channel on your wireless. Wifi has three non-overlapping channels: 1, 6, and 11. If youre on 6, try 11 or 1. It could be that the channel you are on has interference. You can view other wireless devices in your area with something like Netstumbler. Also it helps to turn off the legacy wireless-b compatibility.

A 1GB file taking 80 minutes seems very slow to me.

Thats roughly 2 or 3 megabits per second. Even with a good wireless G connection youre only getting 12 usable mbps. So your best case scenario is something around 20 or so minutes. If you want decent speeds you should run cat-5 or powerline networking. You might do a little better with wireless-n.
posted by damn dirty ape at 4:18 PM on May 27

Wireless is much, much slower than advertised. If you have to transfer such large files on a regular basis, you should invest in some physical 100MBPS ethernet cable.
posted by Electrius at 4:21 PM on May 27 [1 favorite]

It might be a known issue with Vista. Different solutions seem to work for different people:
Possible solution involving auto-tune;
Possible solution involving MS 'hotfix';
and the official word from Microsoft on the problem.

I haven't run into the problem myself (I've successfully avoided Vista), but some friends and coworkers have been stung by it.
posted by Kadin2048 at 4:21 PM on May 27 [1 favorite]

No matter which version of Windows

Does this include trying XP on it, or just the two flavors of Vista? If it includes XP you can ignore my suggestion above. If you've only tested Vista 32 and 64 I would try XP or a Linux livecd on it, and see if Vista is the problem. If the problem is still there, then you know it's a network issue.
posted by Kadin2048 at 4:24 PM on May 27

Ping statistics for 192.168.1.122:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 1ms, Maximum = 2ms, Average = 1ms

Computer A: 192.168.1.122 -56 dBm RSSI 43 quality
Computer B: 192.168.1.142 -74 dBm RSSI 25 quality
Noise Floor: -99 dBm

The router is only broadcasting in G mode and changing wireless channels had no effect. Transfers are always slow to and from Computer A (XP) no matter which which Windows version Computer B is running. It's frustrating that because the network is so slow I'd rather burn files to disc or copy to a USB drive just to use on a computer 15 feet away.
posted by mithiirym at 5:01 PM on May 27

I was moving a lot of data from one computer to another over a wireless link recently and it was taking a long time. In my case, the router was bad, with the wireless radio stopping and restarting every minute or two. I couldn't tell the wireless was dropping, just from looking at the normal Windows interface. The system tray icons didn't indicate an error.

I identified the problem to be the router by watching the Networking tab of Task Manager on both machines during the file transfer. To get there, you can rightclick the taskbar or ctrl-alt-del, and clicking Start Task Manager. Then click on the Networking tab. If you have multiple connections you may have to scroll to find your wireless connection.

During the transfer, look to see that both machines maintain a somewhat steady level of Network Utilization. It's normal for it to be anywhere from a few percent to up to 25% in my experience. It's also normal for it to ebb and flow, creating gently rolling hills and valleys on the graph. What you don't want to see during the file transfer are sharp cliffs where the Utilization drops dramatically down to zero percent and stays there for several seconds at a time. This indicates some sort of problem with the network interface. Keep in mind this applies to a lengthy file transfer. Normal internet surfing will usually show 0% most of the time.

If you are seeing the interface drop out, you can isolate the problem by comparing the Network Utilization graphs of the two computers. If the graphs are similar, showing drop outs at the same time, then the problem lies somewhere with the router. If only one machine is dropping out, then the problem likely lies with the network interface in that computer. In either case it could be failing hardware, a bad config, locational interference, etc, but at least you'll know where the problem lies.
posted by Liver at 6:25 PM on May 27

Have you tried other transfer methods other than the built-in file transfer? You can install filezilla server and run an ftp server.

Or you can run the windows port of iperf and see how much bandwidth you really have. Try different window sizes too.
posted by damn dirty ape at 9:00 PM on May 27

IF your using wireless thats why. Wireless can be very slow. I suggest wiring them into the router if you need faster file transfer
posted by majortom1981 at 6:10 AM on May 28

You could set up an adhoc network between the two machines and leave the router out of it. That would help eliminate it as a possible source of the slow down. Everyone's right in that wireless is actually pretty damn pokey and 2Mbps isn't that bad for G. With copper you can come much closer to saturating the full line speed.
posted by chairface at 4:11 PM on May 28

I've had to accept that a local wireless network just won't be as ideal as I had hoped. Convenience at the cost of slow transfers. Thanks all.
posted by mithiirym at 2:55 PM on July 1