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Atheros AR5BXB112 Wifi can't do 450Mbps

K

kwarwick43

macrumors member
Original poster
Aug 11, 2008
32
0
I recently upgraded the WiFi card in my 3,1 Mac Pro from the standard Apple Airport N Broadcom based two antenna card to an Atheros AR5BXB112 three antenna card.

With the Broadcom card I was able to get 270Mbps link speed connecting to my 2013 AEBS 15 feet away. With the new card I’m able to get 360Mbps (MCS index 21) fluctuating to 300Mbps (MCS index 15), but I was expecting 450Mbps given the close proximity.

Even if I move the AEBS within a foot of the Mac Pro I still only get 360Mbps. I’ve tried re-arranging the order of antenna connections on the card and even swapping in the supposed Bluetooth antenna (since there have been reports of this being mislabeled) but still can’t exceed 360Mbps.

Do I have a bad card or does this sound more like an antenna problem?
 
kwarwick43 said:
I recently upgraded the WiFi card in my 3,1 Mac Pro from the standard Apple Airport N Broadcom based two antenna card to an Atheros AR5BXB112 three antenna card.

With the Broadcom card I was able to get 270Mbps link speed connecting to my 2013 AEBS 15 feet away. With the new card I’m able to get 360Mbps (MCS index 21) fluctuating to 300Mbps (MCS index 15), but I was expecting 450Mbps given the close proximity.

Even if I move the AEBS within a foot of the Mac Pro I still only get 360Mbps. I’ve tried re-arranging the order of antenna connections on the card and even swapping in the supposed Bluetooth antenna (since there have been reports of this being mislabeled) but still can’t exceed 360Mbps.

Do I have a bad card or does this sound more like an antenna problem?
Click to expand...

The card is probably fine, however the antennae for the Mac Pro are all within the metal structure, which forms a pretty handy Faraday's Cage - frankly I'm constantly surprised that MPs' airport works at all.

For example, the same card in a ThinkPad T61 would show connected at 450Mbps, the same card transplanted into an MP would struggle to connect at 216Mbps - In the end I went with a TP Link PCI-E card with antennae outside the casing which connects quite nicely at 450Mbps. I forget the model number but there's a 4800 in there somewhere - uses drivers built into OS X 10.9, and possibly earlier.

Found the link:

http://uk.tp-link.com/products/details/?model=TL-WDN4800
 
I've never been able to get decent wifi upgrade performance in a Mac Pro tower, the antennae inside aren't good enough for these newer cards to get really high speeds and the enclosure itself as the poster above has mentioned has Faraday cage like properties. If you have a USB 3.0 PCIe card it will probably get worse as the ends which connect to the card aren't shielded either which also causes bluetooth madness with mice.

Like the bluetooth fix I do with USB 3.0 card interference you could try DIY shielding the ends with a blob of Araldite resin on top with a sliver of mu-metal bent around covering up the connector protecting it from 2.4 ghz noise. I have never done this with the wi-fi ends before on a Mac Pro as all my clients and myself who demand decent networking performance plugs cat 5e or 6 cable(s) in. I've yet to find any wifi technology that has speeds that claim to be close or even exceed gigabit speeds are anywhere near as good in terms of performance and response as using a proper cable in reality. If you have a spare slot and cannot cat6 cable it using a PCIe card with external antennae is the next fastest thing..
 
Hey, thanks a lot for the responses. I guess my mistake was thinking that since I had excellent stability with the previous card operating at 270Mbps (I believe the maximum for that gen card with 800ns guard interval) that I could expect a solid 450Mbps with a three stream card.

I always found it curious that Apple equipped the Mac Pro with three antennas but the official wifi card only supported two. Perhaps what I'm seeing is why Apple didn't bother with a three stream capable card.
 
Is this card similar to Broadcom's BCM94322MC?

Broadcom's card is the popular suggestion for add-on WiFi card in older Mac Pro. I found out about this AR5BXB112 and I question its credibility. Is it just as functional as Broadcom's card?
 
Those max numbers for WiFi frequently end up like the old EPA Highway number.

With AC wireless in my pros I sometimes see the max of 1300 but far more often the numbers are in the 700-867 range.
 
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