Bluetooth cripples WiFi speeds... XPS 13 (9350) 8260 WiFi card

Hi,

Got my XPS 13 (Unbuntu developer edition) a week ago, and mostly really like it. Certainly a racehorse compared to my XPS 13 M1330!!
I got the Unbuntu version because it had £50 off and came with the Intel 8260 WiFi card, so it does Wireless display.
I had a look at Unbuntu but prefer Windows, so wiped the drive and did a fresh install + installing latest everything it needed.

So, i thought i would try my JBL Bluetooth speaker as i never got BT working properly on the 1330.
Was a bit of a pain but worked it out in the end, great!
While listening to music and looking about on the net i noticed some the internet was slowing down to the point of almost constant buffering on multimedia sites like Twitch and Youtube..
Not sure why, i turned off the BT speaker because it was a distraction, and bingo the everything staring working fine!! So i did some speed tests and found that on my 150mb connection, i was getting the following speeds:

Wired destop PC, 150mb+
XPS13 Wireless, 100mb fairly stable
XPS13 Wireless + BT 20mb - 30mb
XPS13 Wireless BT OFF but Mobile phone BT to speaker ON 85mb - 90mb

I called Dell (Pro support?). After along time of update fails because everything was the latest he wanted to call-out an engineer to replace the WiFi card. I said i would think about it as it was so new i wasn't sure if i shouldn't just return it.

Is anyone else having this issue, or could they try it?

Cheers, Fink

P.s All devices and Wireless hub in the same room a few metres apart.

 

Interference is to be expected; both bt and wifi b/g/n occupy roughly the same 2.4 GHz frequency spectrum. With most bt devices this is not a problem, their data stream being to small to cause too many collisions with wifi for it to have a noticeable impact. BT speakers are a different matter, obviously. Some technologies have been deployed to minimise this effect, but they don't seem to work properly in your situation.

The best solution would be 5 GHz wifi, although that needs a compatible router and doesn't travel well beyond solid walls and ceilings. A possible alternative is to switch wifi to channel 13 (though that will limit theoretical max. to ~80 mbit). Normally that is only available with non-US firmware, so whether you can even choose that channel depends on your router and wifi card.

Also, to be sure, you have bought a no-bezel style laptop. Same as with Apples, this is a form-before-function type of design principle; the wifi antennas are normally placed above the display (behind the bezel) since this gives the best reception. With a 'sleek design' there's no room for the antennas anymore, so they have been relocated to the bottom of the display (can't be placed behind the lcd itself due to interference). Of course, the laptop's bulk is now in the signal's path and they're much, much closer to the USB 3.0 ports, which are known to disrupt the signal as well.

Of course, this pre-meditated design flaw can be remedied, but not without crippling the 'looks' ( !). You'd need two new antennas with longer cables (or just the cables themselves). Next drill two small holes through the top-left and top-right area of the display lid and route the cables through them. The antennas will have to be placed on the outside of the lid, however, so it'd be a good idea to cover them with duct tape or carbon wrap, for example.

 

Yes i forgot to say that i tried 5ghz and it was better, but, the signal dropped off quickly when moving into any other rooms. So unfortunately that isn't a solution that will work for me.

Not sure i would go the DIY route in this instance but your explanation of why, is helpful!

I'm also getting some weird graphics artefacts that others have reported so
I may send this back.

Does the XPS 15 suffer to the same degree?

 

Yes, it's the same form (infinity-edge). A non-idiotically designed laptop would be best, but you could also opt for a sensibly placed 5-GHz range extender.

For alternatives; look at the Latitudes (if you're dead-set on Dell), the EliteBooks, ThinkPads or Zenbooks, none of which would suffer the same problem. But, really, if 'racehorse' is actually important then pay less attention to the looks of a laptop and instead take into account the specific cpu (non-U), graphics card (dedicated), ssd type and/or battery run time. Something like the MSI GS40 or Clevo P640RE would be in a very different league altogether (being at least twice as powerful), though these will suffer from addiction to power outlets.

 

I only used the term "racehorse" in relation to the 2007 XPS M1330 this laptop is replacing. I'm not after particularly fast laptop by today's standards, just a nice compact matte screen ultrabook type of thing, that works. I like this one, but it does feel buggy..?

 

The XPSs are hardly Dell's premium-end series and especially their later models seem to have been rushed through the design phase ...

For a similar, less-buggy system see the ThinkPad T450s. It's also in the low or sub $1000s, can have even better battery life, has a much better screen and keyboard. There's also an ethernet port, so it won't be wifi or nothing. A 940M is optional and even browsers will benefit from that dGPU, so crawling the internet and watching videos may even feel snappier (the better screen will help, too). Pretty good value-for-money, all-in-all. It's no longer available from Lenovo itself, though other stores will still carry it.