Laptop without wifi / USB conflict?

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wolftune
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Laptop without wifi / USB conflict?

Post by wolftune »

I'm needing a new laptop given physical case damage to my current machine. I am otherwise okay with my current model except it has a conflict with the USB and wifi such that I can't use lower-latency settings with USB audio without turning off wifi, and there's times that's a problem. How can I pick a new computer that doesn't have this conflict?
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emarsk
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Re: Laptop without wifi / USB conflict?

Post by emarsk »

I think this kind of info is incredibly hard to find reliably, I sometimes read of small differences from build to build of the same laptop model (some components not being exactly the same etc.).
The first suggestion given here is "disable wireless internet" - and doesn't even mention conflicts with the USB - so the problem is probably not so easy to fix.
That said, I have a Lenovo T440s and it works fine, but when I really need reliability I just switch the wifi off.
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CrocoDuck
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Re: Laptop without wifi / USB conflict?

Post by CrocoDuck »

I had this problem on my old Compaq Presario CQ-61. I was indeed forced to completely unload the wifi kernel modules. Even switching off the wifi with the physical button on the case resulted in xrun frenzy.

I now own an Entroware Apollo 1000 (the older series, this is the latest). It does not have this issue (I don't see any difference with or without wifi). I think the only way to find out whether you might have the issue is to look at lspci and lsusb. Conflicts are created when cards are on the same bus/hub. The Apollo 1000 has separate bus and this seems to avoid the problem. You can find few reviews of the laptop in my blog in signature (the pond). I am preparing the last piece of review these days, as the laptop is now 1 year old.
emarsk wrote:I think this kind of info is incredibly hard to find reliably, I sometimes read of small differences from build to build of the same laptop model (some components not being exactly the same etc.).
Indeed. It would be best to boot a live into a test laptop, have a look at lspci and lsusb and maybe have a test audio session... so bad this is almost never possible...

wolftune
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Re: Laptop without wifi / USB conflict?

Post by wolftune »

Thanks for the replies. I almost went with a T440s and may regret not doing so, but I now have a used X1 on the way and will find out whether it has this issue. If it does, I'll have to return it and go get a T440s. I heard that the T440s (or T440p) is superior in most regards, although there's trade-offs either way. It would be *so* ironic if the X1 has the problem and thus can't let me use ethernet (it has no ethernet port) to have network connection with low-latency audio so I go with T440 to get the ethernet port but then not need it because it has no wifi conflict. I guess that means I really should ignore the ethernet issue. Either the X1 will work or it won't… I'll report back
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folderol
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Re: Laptop without wifi / USB conflict?

Post by folderol »

I found wifi entirely unreliable on my laptop so disabled it in the bios - there's wired Ethernet anyway.
Later I got one of those USB wireless 'bugs' which has turned out to be excellent, but I only ever plug it in when I need it. win-win :)

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sadko4u
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Re: Laptop without wifi / USB conflict?

Post by sadko4u »

On my laptop, USB, FireWire and WiFi work on the same interrupt vector.
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gimmeapill
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Re: Laptop without wifi / USB conflict?

Post by gimmeapill »

No 100% reliable method to determine what IRQs will be shared - unless you are lucky enough find a detailled linux installation report.
However, by studying carefully the specs of the cpu + the service manual (this is where you usually have the internal system diagram), it should be possible to guess more or less what will be the overall I/O performance. Needless to mention, if you see something like an internal USB hub it is not a good sign..
I would advise to target mid range business class notebooks (avoid the lighest ultrabooks, cheaper entry level notebooks, and manufacturers that do not provide a proper service manual).

That T440s looks perfectly fine to me.
If you look at the specs of the cpus, they are given as able to handle 4 x USB3ports + 12 x PCIe 2.0 lanes
http://ark.intel.com/products/75459/Int ... o-2_60-GHz

And from the tech specs of the notebook it doesn't looks like they cut much on the I/O side:
http://shop.lenovo.com/us/en/laptops/th ... tech_specs

But that's not exactly what I would call a cheap model either...

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Re: Laptop without wifi / USB conflict?

Post by wolftune »

Thanks for that detailed suggestion. FWIW, I ended up ordering a used Thinkpad X1 Carbon (and then had serious second-thoughts with the only 2 USB ports and no ethernet, but I decided not to cancel, it was a good price). I'll see if that works, it's a bit of a risk. If it works, great. *Some* of the specs are better than what I saw in T4xx series. But I think I should have gone with a T440s or T450s. If the X1 doesn't work out well, I'll be seeking a T440s or T450s, those seem to be the best all-around machines in lots of ways, just not quite as light and portable as the X1 (which isn't a top priority, even if it's nice). I'll report back what I find about the X1.
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wolftune
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Re: Laptop without wifi / USB conflict?

Post by wolftune »

So, after receiving a damaged X1 (though it was just a loose cable needed reconnecting), I sent it back and found a good used T450s for not much more. I definitely got a cheaper price than most T450s listings out there. No SSD, just regular hard-drive and only 4GB of RAM, so I can update those. I do have an i7 processor and IPS screen! I can't get both batteries fully recognized, but otherwise system is working.

I was able to get down to a SHOCKING 16 sample buffer while running Guitarix live and NO xruns!!! That's 0.3ms latency! Holy shit! And that's without turning off networking, I still had Firefox running even! Realistically, I'll just use 64 sample buffers and never bother going to 32 or 16, but awesome that was possible.

The glitchiness I had with my UMC404 is gone basically, but the preamps still don't sound as good in the high frequencies as the Scarlett series.

Anyway, thanks for the recommendations. Sorry I didn't get to verify whether the X1 solved this interrupt issue as well. At any rate, the T450s is a better computer for my needs in almost every regard. 3 USB ports instead of 2 being the biggest factor.

I never thought I'd get an affordable computer that really did this well. It's pretty close to being perfect for me. Working great with KXStudio repos and KDE Neon. I hope to get around to finally having new music to share with this improved setup!
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gimmeapill
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Re: Laptop without wifi / USB conflict?

Post by gimmeapill »

Good to know, thanks for the update!

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