1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Notebooks Reasons *not* to buy an XPS 13?

Discussion in 'Hardware' started by Gareth Halfacree, 10 Oct 2017.

  1. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    I've been having some problems with the wireless on this thing, even after replacing the Killer thing with a proper Intel jobby: dropping off the 5GHz band, refusing to transfer packets for a bit, and occasionally even just refusing to authenticate until I reboot the thing. S'one of those things where you don't know whether to blame the laptop or the router, and it does seem to be better when I'm not in the congested part of the 5GHz spectrum - but, sadly, Netgear's radar detection is a little over sensitive and it keeps throwing itself off clear and free Channel 112 and back to noisy ol' Channel 36.

    So, I've gone for the nuclear option: iwlwifi backports, compiled from source and with the latest firmware (-31 instead of -21 from Ubuntu's 16.04.3 repos and -22 direct from Intel.) Only time will tell if it's fixed the problem, though, but I can say that it has made iwconfig think the Wi-Fi card has no wireless extensions available...
     
  2. theshadow2001

    theshadow2001 [DELETE] means [DELETE]

    Joined:
    3 May 2012
    Posts:
    5,212
    Likes Received:
    157
    I must say if the problem isn't following the wifi card around it seems like it would be something else. What about 2.4Ghz?
     
  3. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    Well, the problem with the Killer card was different: that wasn't allowing traffic on 5GHz at all, ever.

    2.4GHz is usually better, but sometimes has the same trouble. I'm now typing from a rock-solid 5GHz connection which is happily maxing out my 60Mb/s broadband line, but only after moving the channel on the router back into the hundreds - before doing that I was getting 25Mb/s at best.

    It's a puzzler, this one!
     
  4. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    It *may* - or may not, who knows - be a regulatory domain issue.

    Code:
    blacklaw@xerxes:~$ iw reg get
    country 00: DFS-UNSET
       (2402 - 2472 @ 40), (6, 20), (N/A)
       (2457 - 2482 @ 20), (6, 20), (N/A), PASSIVE-SCAN
       (2474 - 2494 @ 20), (6, 20), (N/A), NO-OFDM, PASSIVE-SCAN
       (5170 - 5250 @ 80), (6, 20), (N/A), PASSIVE-SCAN
       (5250 - 5330 @ 80), (6, 20), (0 ms), DFS, PASSIVE-SCAN
       (5490 - 5730 @ 160), (6, 20), (0 ms), DFS, PASSIVE-SCAN
       (5735 - 5835 @ 80), (6, 20), (N/A), PASSIVE-SCAN
       (57240 - 63720 @ 2160), (N/A, 0), (N/A)
    That ain't right, is it? Quick switch of the card into managed mode and I can fix that...

    Code:
    root@xerxes:~# modprobe -r iwlwifi && modprobe iwlwifi lar_disable=1
    root@xerxes:~# iw reg set GB
    root@xerxes:~# iw reg get
    country 98: DFS-ETSI
       (2402 - 2482 @ 40), (N/A, 20), (N/A)
       (5170 - 5250 @ 80), (N/A, 20), (N/A), NO-OUTDOOR
       (5250 - 5330 @ 80), (N/A, 20), (0 ms), NO-OUTDOOR, DFS
       (5490 - 5710 @ 160), (N/A, 26), (0 ms), DFS
       (57000 - 66000 @ 2160), (N/A, 40), (N/A)
    
    It still ain't quite right, as it's claiming country code 98 instead of GB like wot I told it to be - but that might be a side effect of the fact my stupid Netgear router doesn't ask for a country-based regulatory domain but a region-based one, and when you choose 'Europe' it helpfully broadcasts a country code of DE...

    Still, GB, DE, and 98 should all be identical in terms of what they are and aren't allowed to do radio-wise, so fingers crossed this has finally fixed the glitch!

    EDIT: Y'see, when it works it's perfectly happy...

    speedof.me_17-10-23.png
     
    Last edited: 23 Oct 2017
  5. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    Ooh, now I've got a new thing to add to the list of annoyances: I may have tweaked the power a little too much, because it's now aggressively downclocking to about 450MHz while I'm trying to watch something on Amazon Instant Video - which ain't enough to keep the video stream fed and causes it to glitch.

    <sigh>

    EDIT:
    Easily and quickly fixed with a switch to the performance CPU governor, though - with an obvious impact on battery life, mind!
     
    Last edited: 23 Oct 2017
  6. bawjaws

    bawjaws Multimodder

    Joined:
    5 Dec 2010
    Posts:
    4,073
    Likes Received:
    716
    Ah, the curse of the inveterate tinkerer :D
     
  7. sandys

    sandys Multimodder

    Joined:
    26 Mar 2006
    Posts:
    3,733
    Likes Received:
    253

    You need to up the GPU clock rather than the CPU, I had the same problem.
     
  8. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    Sometimes I think life would be so much easier if I just bought a Windows laptop and didn't fiddle. But where's the fun in that!

    I can get stable video if I set a minimum clockspeed of 700MHz through cpupower, which strangely allows it to downclock to around 600MHz - which is good enough to keep Amazon Instant Video from glitching, though going in and out of full screen takes a couple of seconds each time. Still idling at sub-3.5W, currently at 3.97W as I type this and an alert pops up above the text entry box - so I'm happy enough with that.
    Seems to be solved with a minimum real-world CPU clock of 600MHz, as far as I can see - although I'm happy to try other tricks if you think it'll work better!

    EDIT: Switching to the performance governor idles at around 4.14W, so frankly unless I'm absolutely gasping for as much battery life as possible I might just leave it there by default.

    EDIT EDIT: Idle might be similar, but watching Amazon Video on the performance governor sits at about 12-16W, whereas doing the same on the powersave governor with a 750MHz minimum clock (figured I'd add a little wiggle-room) is 6-7.5W - so powersave with a manual lower limit it's going to be!
     
    Last edited: 23 Oct 2017
  9. sandys

    sandys Multimodder

    Joined:
    26 Mar 2006
    Posts:
    3,733
    Likes Received:
    253
    Not sure what is best, just upping GPU was good enough for me, nor do I know how you do it in Linux but I have application specific power profiles with custom speeds and voltages, well I did, since a new SSD I've not set that all up again as I am mostly tethered these days, but you can get quite aggressive with Intels XTU.
     
  10. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    S'dead easy: you just write the number you want in megahertz to /sys/class/drm/card0/gt_min_freq_mhz (or gt_max_freq_mhz to set an upper limit), then you can read back the current speed at any given time by catting /sys/class/drm/card0/gt_cur_freq_mhz.

    Can't say that a minor boost to that does much, though, especially compared with the CPU tweak. It was certainly worth a shot - ta for suggesting it!
     
  11. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    Bwa-ha-haaa!

    Screenshot from 2017-10-24 22-05-02.png
    That's not even idle, I'm SSH'd into my server to chat on IRC and actively using my web browser - *and* I've still got the 750MHz minimum clock enforced. I've been using it off and on this evening, too. Crazy stuff!
     
    MLyons likes this.
  12. RedFlames

    RedFlames ...is not a Belgian football team

    Joined:
    23 Apr 2009
    Posts:
    13,734
    Likes Received:
    2,162
    Esp given my 'rents pile of Tosh[iba] doesn't manages a quarter of that.

    Does wired vs wireless make much of a difference to battery life?
     
  13. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    Dunno, but as it doesn't have an Ethernet port and I'd have to use a USB dongle I'm guessing wired might actually take a smidge more power than wireless.
     
  14. RedFlames

    RedFlames ...is not a Belgian football team

    Joined:
    23 Apr 2009
    Posts:
    13,734
    Likes Received:
    2,162
    Serves me right for not paying attention... thought the xps13 had ethernet... still, pretty impressive how far you can eke out the battery and much stuff you can turn down/off and still have a usable machine [the fact linux will run on a toaster probably helps there too]
     
  15. sandys

    sandys Multimodder

    Joined:
    26 Mar 2006
    Posts:
    3,733
    Likes Received:
    253
    Considering the size that's a massive battery, mine only has a 41Wh battery.
     
  16. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    I think the XPS 15 might, but not the 13 - just two USB 3.0 ports, a USB 3.1/Thunderbolt Type-C, 3.5mm jack, and SD card slot. Plus some weird locking slot that I think was cheaper for Dell to license than a Kensington slot but no bugger sells a lock for.
    Aye, it's pretty hefty - takes up about half the chassis, far as I could see as I was changing the Wi-Fi card!
     
  17. RedFlames

    RedFlames ...is not a Belgian football team

    Joined:
    23 Apr 2009
    Posts:
    13,734
    Likes Received:
    2,162
    Bit like the modern macs where the motherboard is a tiny sliver tucked to one side and the rest of the chassis is battery pretty much [and they still can't match your 18 hours].

    Only downside is [i'm guessing] said battery is not removable on the Dell [or the mac].
     
  18. Gareth Halfacree

    Gareth Halfacree WIIGII! Staff Administrator Super Moderator Moderator

    Joined:
    4 Dec 2007
    Posts:
    14,427
    Likes Received:
    3,219
    It actually is! I mean, not field-removable like the Inspiron I had back in the 90s, but you just pop the back cover off (about seven or eight T5 screws and a Philips) and the battery's right there. Unscrew it, unclip it, swap it over, clip it, screw it, put the back cover and screws back and job's a good 'un. There's an iFixit guide 'ere with pretty pichures.
     
    Guest-23315 and RedFlames like this.
  19. RedFlames

    RedFlames ...is not a Belgian football team

    Joined:
    23 Apr 2009
    Posts:
    13,734
    Likes Received:
    2,162
    Whilst it's not exactly my idea of removable, 'field-removable' as you put it. It's still one up on most modern laptops.
     
    MLyons likes this.
  20. yuusou

    yuusou Multimodder

    Joined:
    5 Nov 2006
    Posts:
    2,493
    Likes Received:
    569
    Isn't that a Daft Punk song?
     

Share This Page