Why is my higher spec PCIe WiFi card giving Lower signal strength than usb adapter?

[chris_shadez]

Currently using a TP-Link 300mbps High gain a/b/g/n USB wireless adapter (dual antenna);
http://www.amazon.co.uk/gp/product/B00416Q5KI?psc=1&redirect=true&ref_=oh_aui_detailpage_o08_s01
which always gives me full reception/signal strength bars (5/5) and speedtest.net up/down speed is near same as directly wired to router.

Thought I'd switch to a PCIe card to get rid of the cable & external dongle device, so bought a TP-Link 450mbps dual band (triple antenna)
http://www.amazon.co.uk/TP-LINK-TL-WDN4800-450Mbps-Wireless-Express/dp/B007GMPZ0A/ref=pd_rhf_sc_p_img_15
only to notice the wifi signal strength dropped to 3/5,The connection speed dropped too;

Speedtest.net averaged down/up;
USB : 7.6mb/s - 0.91mb/s
PCIe: 6.2mb/s - 0.81mb/s

What I tired;
-The usb adapter also was placed at rear of pc, moving it around tower makes no difference. Turning the pc tower back-to-front (lol) made no difference so I don't see the positioning being the issue.
-Changing to a set specific (vs auto) wireless channel showed no improvement.
-Tried Drivers from; originally 1) Windows 8 auto driver search, 2) CD that came with the card 3) TP-Link website
Neither of the latter two driver changes made a difference.

Using it in a decade old tower gave same results 🙁

Reverted to using the usb.
Just wanted to see if there are known issues and solutions to this before i get a refund.

Thanks.

in case asked later -
Windows 8.1 64bit
Motherboard - MSI Z97 MPOWER
Full Spec - http://uk.pcpartpicker.com/b/hcRG3C

 

[thx1138v2]

I suspect the newer one has a more sensitive receiver and is picking up spurious signals from your environment, i.e. neighbors' wifi and/or other equipment. There's really no way to tell unless you have a good spectrum analyzer handy but it's really not worth analyzing because there's not much you can do about it. Just go with what works. That's one of the reasons I used wired connections if at all possible.

 

[chris_shadez]

Thought it could be that too but according NirSoft WifiInfoView tool, the pcie card shows it to be picking up just 2 networks @18% other than my own. "Signal Quality" @ 40-44%
The usb adaptor rates signal quality @ 99% and picks up 9 other networks ranging @15-30%...

 

[Solandri]

Speedtest.net averaged down/up;
USB : 7.6mb/s - 0.91mb/s
PCIe: 6.2mb/s - 0.81mb/s

Speedtest is a poor way to test your wifi speed, as it's going to be limited by the slower of your wifi and Internet connection.

Your wifi speed is symmetric. If it can manage 6 MB/s down, it can manage 6 MB/s up. The fact that the PCIe adapter's upload speed was slower than the USB's despite it only being 0.8-0.9 MB/s strongly suggests the difference you measured was due to fluctuations at your ISP, not a real difference between adapters.

A good, strong 802.11n signal should get you about 11-15 MB/s. The next step down is typically around 5-6 MB/s. This also suggests the speedtest results you got are being limited by your ISP, not your wifi network.

Try transferring a 1-2 GB movie file locally - between a shared folder on a wired computer to/from your wireless-connected computer - and seeing what kind of speeds you get. If you're comfortable with computers, try setting up an iperf server and client and using that to measure LAN/wifi speeds.

http://openmaniak.com/iperf.php

only to notice the wifi signal strength dropped to 3/5,

Bars are meaningless. If you can get your adapters to show you how many dB of signal they're getting (RSSI), then you can compare the two. The thresholds for number of bars are completely arbitrary, and can change with software version. Apple famously overstated the bars of signal on their original iPhone (made it display 4 bars even if the signal was weak) to trick people into thinking it was getting a stronger signal than other phones.

 

[chris_shadez]

Speedtest.net averaged down/up;
USB : 7.6mb/s - 0.91mb/s
PCIe: 6.2mb/s - 0.81mb/s

Speedtest is a poor way to test your wifi speed, as it's going to be limited by the slower of your wifi and Internet connection.

Your wifi speed is symmetric. If it can manage 6 MB/s down, it can manage 6 MB/s up. The fact that the PCIe adapter's upload speed was slower than the USB's despite it only being 0.8-0.9 MB/s strongly suggests the difference you measured was due to fluctuations at your ISP, not a real difference between adapters.

A good, strong 802.11n signal should get you about 11-15 MB/s. The next step down is typically around 5-6 MB/s. This also suggests the speedtest results you got are being limited by your ISP, not your wifi network.

Try transferring a 1-2 GB movie file locally - between a shared folder on a wired computer to/from your wireless-connected computer - and seeing what kind of speeds you get. If you're comfortable with computers, try setting up an iperf server and client and using that to measure LAN/wifi speeds.

http://openmaniak.com/iperf.php

only to notice the wifi signal strength dropped to 3/5,

Bars are meaningless. If you can get your adapters to show you how many dB of signal they're getting (RSSI), then you can compare the two. The thresholds for number of bars are completely arbitrary, and can change with software version. Apple famously overstated the bars of signal on their original iPhone (made it display 4 bars even if the signal was weak) to trick people into thinking it was getting a stronger signal than other phones.

NirSoft WifiInfoView tool, the pcie card shows it to be picking up just 2 networks @18% other than my own. "Signal Quality" @ 40-44%
The usb adaptor rates signal quality @ 99% and picks up 9 other networks ranging @15-30%...

Doesn't this prove it really is the signal strength of the device?

edit- properties in the stated tool show
pcie RSSI is -87
usb RSSI is -64

I do realise speetest.net type of method is poor test of wifi speed but just stated it as it was my main concern vs the usb adapter - a drop in connection speed on the same AP, at the same distance

 

[Solandri]

NirSoft WifiInfoView tool, the pcie card shows it to be picking up just 2 networks @18% other than my own. "Signal Quality" @ 40-44%
The usb adaptor rates signal quality @ 99% and picks up 9 other networks ranging @15-30%...

Signal quality is ratio of signal to noise.

edit- properties in the stated tool show
pcie RSSI is -87
usb RSSI is -64

That pretty much cements it. Something is seriously wrong with your PCIe card. It's like the antenna(s) aren't even connected. The noise floor is usually around -85 to -95 dB. A "decent" signal is around -60 to -70 dB. Right next to the router is around -30 dB. Each 3 dB is a doubling of signal strength. So your USB adapter is picking up over 200x the signal strength the PCIe adapter is.

 

[chris_shadez]

Thanks for confirmation. I did swap the card into another pc and back as mentioned earlier, so I am sure they are well connected.
Think it's a faulty card then? Ask for replacement?