Odd N speed problem, Dell, different speeds on different SSID bands?

[irvsp]

Windows 7 Home Prem., x64. New Dell XPS 8500...

Has had 3 network (wireless) devices in it.

1. Original Dell 1703 N Wireless 1/2 card
2. Intel Centrino 2230 Wireless-N 1/2 card
3. Linksys USB AE2500 Dual band device

First two are 1/2 cards and single 2.4Ghz band cards, the last Dual 2.4 and 5Ghz band USB device.


For testing the first 2, 2 routers were used, an older LinkSys WRT310N, and a newer dual band ASUS RT-N56U.


The first adapter would only connect at 150Mbps. This is an internal device with 2 antenna's at right angles to each other internally at the top of the case.


The second adapter did the same, but if you changed ANY network card setting, it would then connect at 300Mbps. However, upon re-booting it always reverted to 150Mbps.


I should note at this point again that it worked the same with either router serving up the N-Speed wireless signal (WPA2 authentication). I should also note this computer replaced an older HP XP Media Center computer with a LinkSys 14x WMP300N card that always connected at 270Mbps in the same physical location, about 10 feet from the router (both had been used in the past with that system).


Dell, since this is a NEW system has spent MANY hours on the computer physically remotely and has probably messed with every possible setting all to no avail.


So I was sent the 3rd device. Interestingly, since it is dual band, I tried the 2.4Ghz band first as it was set. It connected at 144Mbps???? Odd, but... So I then enabled the 5Ghz band and that SAME device connects at 300Mbps!!!


How can this be? Is there something 'wrong' in the OS limiting the 2.4Ghz connect to 150Mbps (or less)?


The system came with McAfee Security Suite and I've even disabled this to no avail.


Any thoughts or suggestions?


I was thinking it was possibly the fault of the system design, only 2 antenna's, and I know they are connected and the wiring is good. Still doesn't explain why the USB also gets a low connect speed.


Both myself and Dell have looked at the router settings and can't see anything that would LIMIT the connection?


I'm very confused over this?


Irv S.

 

[JackMDS]

Not directly related but Disabling the McAfee Security Suite does not get it out of the system it keeps intervening with the TCP stack even when "disabled".

Get rid of it, clean after it, and use Win native Firewall with the free Security Essentials.

http://windows.microsoft.com/is-IS/windows/products/security-essentials/product-information

If you want to make any sense from evaluating the Wireless get all Wireless devices out, and use then one at the time. When installing each device in its turn, make sure that only the drivers are Installed and Not the rest of the "cr*p" that usually comes with it.

To evaluate how it works it does not mean much the number that appears in the Card's properties. Measure real Network Transfer of large file (250 MB) between the computer and another Networked computer.

 

[irvsp]

Not directly related but Disabling the McAfee Security Suite does not get it out of the system it keeps intervening with the TCP stack even when "disabled".

Oh, I know that well, just tried to rule out it from being part of the problem. I even stopped loading it a few time.

http://windows.microsoft.com/is-IS/windows/products/security-essentials/product-information[/URL]

If you want to make any sense from evaluating the Wireless get all Wireless devices out, and use then one at the time. When installing each device in its turn, make sure that only the drivers are Installed and Not the rest of the "cr*p" that usually comes with it.

To evaluate how it works it does not mean much the number that appears in the Card's properties. Measure real Network Transfer of large file (250 MB) between the computer and another Networked computer.

I am reluctant to remove it. I'd rather leave it for now. McAfee seems to be working well, and I don't think it is part of the problem, not if the 5Ghz band works correctly. I do have another Norton ISS I can put on the system though if need be, the old one had it and it is a 3PC license with only 2 used.

I am going strictly by the Windows reports from the connectoid. File transfer is well below this, I know.

I can't understand why the difference.

There are physically only 2 wireless devices in the computer at this time. The Intel card is DISABLED in Device Manager and the LinkSys USB is active. The Dell card is long since been removed (Intel card uses the same internal 1/2 card slot on the motherboard).

Could there be ANY TCP/IP setting (GLOBAL) or Router setting that could be the cause? One that effects only the 2.4Ghz band?

 

[JackMDS]

Ok, then read this thread (to the end).

http://forums.anandtech.com/showthread.php?t=2269787

 

[irvsp]

Ok, then read this thread (to the end).

http://forums.anandtech.com/showthread.php?t=2269787

Jack, I guess I miss the point of the post?

This IS a desktop, and it replaced an older one in the same spot. That older one had no problem with either router.

Of the 3 wireless devices (old computer was wireless too) on the new computer, each when tested with both routers reacted differently. As I said, nothing could make the original Dell card connect above 150Mbps. The 2nd Intel card could if you 'played' with it, but not on booting. Both of these cards are 2.4Ghz only. The last one being a dual card, when running at 5Ghz does connect at boot at 300Mbps.

The question is more than why? What is holding the 2.4Ghz band back to 150Mbps or less on 3 devices? One if you modify its settings will connect at 300Mbps, but will not stay there when the system is re-booted and starts off at 150Mbps.

Is there something 'wrong' within Windows? Is it a setting on my router? On the Asus RT-N56U I tried 3 different flashes, the official, a Russian one, and an Asus Beta. The last two have more settings, but nothing I've played with changes the speeds. Oh, I should mention the old computer was moved to a new location and still connects at 270Mbps.

I guess I have one more possible test I can make? I have another Windows 7 Home Prem. x64 computer that is now wired to the router. I guess I could move the USB wireless adapter to that machine and see how it connects at 2.4Ghz?

This question isn't about Transfer speed, it is why the connectiod and other apps that show the wireless connect speed show 150Mbps vs. the full 300Mbps these devices are capable of at 2.4Ghz.

Irv S.

 

[imagoon]

Have you tested the actual speeds? There are plenty of other adapters that report they connected at max speed to the OS but never actually sync at that speed. I have a laptop here that always says 54mbps when it actually only get around 2mbps in the room it is in.

The sync rates are arbitrary and rarely give you a real indication of the quality of the connection.

 

[irvsp]

Have you tested the actual speeds? There are plenty of other adapters that report they connected at max speed to the OS but never actually sync at that speed. I have a laptop here that always says 54mbps when it actually only get around 2mbps in the room it is in.

The sync rates are arbitrary and rarely give you a real indication of the quality of the connection.

Yes, I have but N-Speed is hard to tell. I go from the wired 1Gbps to the wireless, but it seems the 'router' even though it knows the wired computer connects to it at 1Gbps, I never get more than 100Mbps or so between the two machines transferring files, so that is no indication of true speed. Our internet speed is 40Mbps and via FTP I can achieve that. I have NO way to exceed 150Mbps.

However, there are many programs that determine the reported device connect speed, and ALL agree, 150Mbps except for the LinkSys AE2500, which reports 144Mbps at 2.4Ghz and 300Mbps at 5Ghz. Also the Intel 2230 when 'forced' into 300Mbps as well.

Irv S.

 

[imagoon]

Yes, I have but N-Speed is hard to tell. I go from the wired 1Gbps to the wireless, but it seems the 'router' even though it knows the wired computer connects to it at 1Gbps, I never get more than 100Mbps or so between the two machines transferring files, so that is no indication of true speed. Our internet speed is 40Mbps and via FTP I can achieve that. I have NO way to exceed 150Mbps.

However, there are many programs that determine the reported device connect speed, and ALL agree, 150Mbps except for the LinkSys AE2500, which reports 144Mbps at 2.4Ghz and 300Mbps at 5Ghz. Also the Intel 2230 when 'forced' into 300Mbps as well.

Irv S.

The point of my post is the connect speed is rarely accurate. If you can't simulate 150mbps why do you care if it shows you 300mbps? For the wired, you need something that can actually push the wired connection to see if you actually get 1gb/s. You may also need to mess with the network metrics to force data out over the 1 gig cable also.

 

[VirtualLarry]

My laptop and netbook only connect at 65Mb/sec to my DD-WRT N routers, even though the routers themselves connect at 144Mbit/sec between routers in WDS mode.

Edit: My netbook says 72Mbit/sec right now.

 

[irvsp]

The point of my post is the connect speed is rarely accurate. If you can't simulate 150mbps why do you care if it shows you 300mbps? For the wired, you need something that can actually push the wired connection to see if you actually get 1gb/s. You may also need to mess with the network metrics to force data out over the 1 gig cable also.

I guess I'm be a bit anal here, but it is a new Dell for my wife. First thing I did was 'test it out' and found many image problems. A continual WMI error in the Event Log, turned out to be an MS image problem easily fixed. PERFMON /REPORT failed with a time-out, that 'magically' fixed itself 2 months after we got the computer. So I'm suspicious of the Dell installed image. After I spent a month customizing the computer for my wife, installing apps and games, moving e-mail client and browsers and needed private data, I was reluctant to do Dell's last suggestion, they would mail me the Windows Install Media and have me do a CLEAN Windows 7 install. I was warned I'd probably need to call them to get some files that were not included on the DVD's I had (such as McAfee) and then maybe all would work?

I do have 2 1Gbps computers connected to the router and the router has 2 USB drives on it as well. Nothing I can think of can get me past the transport speed to either the other computer or the USB's past the 100Mbps barrier? It generally starts around 14MBpd (112Mbps) and settles down around 10 to 12MBps (as measured by Explorer++'s dialog box on the transfer) which is 80 to 96Mbps. The USB should be 400Mbps max., and is no where near it.

I really suspect the router here, I recall reading that depending on the OS on the router and if it uses SMB transfers, that 100Mbps could be the underlying limit. One of the reason I've tried 2 routers and changing flashes.

If you know some general TCP/IP settings I should mess with, I'm all ears...

On my 1Gbit machine, results from netsh int tcp show global

============
Current settings:
-----------------
Querying active state...

TCP Global Parameters
----------------------------------------------
Receive-Side Scaling State : enabled
Chimney Offload State : enabled
NetDMA State : enabled
Direct Cache Acess (DCA) : enabled
Receive Window Auto-Tuning Level : normal
Add-On Congestion Control Provider : ctcp
ECN Capability : enabled
RFC 1323 Timestamps : disabled
** The above autotuninglevel setting is the result of Windows Scaling heuristics overriding any local/policy configuration on at least one profile.
======

Irv S.

 

[irvsp]

Oh, another oddity here. No matter WHICH wireless network card is used, inSSIDer always reports the 2.4Ghz SSID as a 300 speed signal? Even when the devices only report a 150Mbps connection speed? I strongly suspect a Windows TCP/IP error.

Irv S.

 

[imagoon]

Oh, another oddity here. No matter WHICH wireless network card is used, inSSIDer always reports the 2.4Ghz SSID as a 300 speed signal? Even when the devices only report a 150Mbps connection speed? I strongly suspect a Windows TCP/IP error.

Irv S.

That is normal. Again... the displayed speed is rarely accurate. Windows gets it from the wireless driver. If the wireless driver decides to tell you it has a 2terabit/s connection, Windows will happily display it.

As for above... running a transfer to a USB attached devices to a small router is hardly a test of the network. A) USB B) router with likely underpowered CPU / not enough RAM C) transferring to a multipurpose device D) cheap device, is never going to come out well. You need to test with an application the removes other hardware from the mix like iperf.

Remember also that wireless in a conflict medium with a high number of collision / error frames and lost packets. You can't even get max N speed in a radio dampened lab. You're not going to get perfect performance out of it in the real world. I have worked with building wide wireless deployments with and even though the various computers and phones report 54mbps / 300 mbps all day they controller nearly always show then connecting in the sub 20mbps on the G networks and somewhere in the 80's (at best) on the N side.

It is all about the radios and how the drivers do things.

 

[JackMDS]

A Dual Band Router with a Dual Band card will Definitely do better than anything else.

Try the Linksys USB with the Asus.

Do not plug the USB directly on the computer get a 3 Feet USB extension and plug it to the computer, then plug the Linksys USB to the other end and put it High above the system.

Or get this for the most cost effective solution - http://www.newegg.com/Product/Produc...&SID=u00000687
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The issues that you confront occurs when people are Not aware that the general available info about Networking is coming from marketing people Not form Technical people.

If you really want to be able to solve your problem you have to invest in some pure learning.

BTW - WIFI 300 feet indoor, as many Data Sheets state is a "Yeti" thing too. - :sneaky: - :biggrin: