CPU 100% on ac86u

Vimes

Regular Contributor
^^^^^ I did notice at this page...



the HD's etc recommended. It also suggested an external PSU for USB HD's if possible for stability. I imagine the external PSU would be applicable more to the larger 3.5" external HD's.

From the little I understand USB 2 is 500mA and USB 3 is 900mA in total load capacity.

20201016_161606.jpg

The WD 1TB HD seems to draw around 550mA or so, when transferring files.

Good result for you, along with your journey and 384.19.

EDIT:

Added 750GB Crucial SSD within an enclosure and running off a USB 3 port. Whilst transferring files the power consumption can be seen

20201018_123249.jpg

much less, as expected, than the WD 1TB 2.5" mechanical drive.
 
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gattaca

Senior Member
^^^ Yeah drawing near max from a USB2 port 24/7... never really good to run something near 100% for 24/7 even though I know it's got some buffer. Thanks for posting the USB current limits.

This is the page where we were posting iotest results in 2018 from various drives.
The only drive I recall beating the SSD/UGREEN/USB was in a Samsung T5 500 GB ext4 RT-AX88U USB3 ...

 

thecheapseats

Regular Contributor
<snip>... It also suggested an external PSU for USB HD's if possible for stability. I imagine the external PSU would be applicable more to the larger 3.5" external HD's.

From the little I understand USB 2 is 500mA and USB 3 is 900mA in total load capacity.

The WD 1TB HD seems to draw around 550mA or so, when transferring files.
usb2 @ 500mA and usb3 @ 900mA are at 5 volts only and most spinner drives (3.5") require both 12volts and 5volts - there are ways to get 12v (boosted) from a 5volt supply but I've never seen a supply like that, nor would I use one...

additionally, hanging anything off a usb port other than an usb stick - best practices is use an external power supply unless the ac-to-dc converter of the host device (router, raspberry pi, etc.) is spec-ed high enough to handle the additional 5v amp draw of an ssd - most are not... looking at a few spare ssd drives I have lying around, most are rated at 1amp to 1.7 amps...
 
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Vimes

Regular Contributor
usb2 @ 500mA and usb3 @ 900mA are at 5 volts only and most spinner drives (3.5") require both 12volts and 5volts - there are ways to get 12v (boosted) from a 5volt supply but I've never seen a supply like that, nor would I use one...

additionally, hanging anything off a usb port other than an usb stick - best practices is use an external power supply unless the ac-to-dc converter of the host device (router, raspberry pi, etc.) is spec-ed high enough to handle the additional 5v amp draw of an ssd - most are not... looking at a few spare ssd drives I have lying around, most are rated at 1amp to 1.7 amps...

Agree with the thoughts of an external PSU if possible.

I ended up connecting it to my WD "My Cloud" 6TB external drive, which is connected to my LAN. By doing that the WD device accumulates that storage with its own and is available to share across the LAN. I hadn't realised the power requirements of a SSD, then again I would have checked before putting one in a USB enclosure.
Good point on the larger 3.5" models, forgot that they also need 12v.
 

Vimes

Regular Contributor
^^^ Yeah drawing near max from a USB2 port 24/7... never really good to run something near 100% for 24/7 even though I know it's got some buffer. Thanks for posting the USB current limits.

This is the page where we were posting iotest results in 2018 from various drives.
The only drive I recall beating the SSD/UGREEN/USB was in a Samsung T5 500 GB ext4 RT-AX88U USB3 ...


I am guessing as Asus have their own page, as posted, listing drives that are compatible with their routers then the ports are up to supplying the current needed for certain HD's.
Thanks for posting that link, some good information there.
 

gattaca

Senior Member
^^ That's a very good point and posting! TY!

USB2.0 = 500mA / 2.5W
USB3.0 = 900mA / 4.5W

The power rating never crossed my mind. I've been lucky. I always use the smallest capacity 40-250GB SSD. Those tend to consume the fewest watts with most today remaining well under 2W but can ramp upward with heavier workloads. Also many times these case makers will certify their cases with SSD product lines from Samsung, Crucial and many other. I'd look for that too.

The larger the SSD's capacity, the more power it requires - especially under heavy workloads.

Yes, I would not run a 2.5" HDD (spinners) on just a single USB2.0 port alone - use an external PSU. UGREEN makes some of those too but I have not used those models.

My go to SSD today is the smallest Crucial MX500/250Gb unit which clocks in at 70mW.

Thanks for reminding us to watch the drive + case ratings new or used! ;)


1602984410056.png

MX500 specs -> http://brochure.stebis.nl/MX500.pdf

Stay safe, stay alive. Peace.
 
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OBENZ

Regular Contributor
I'm glad my issue brought attention to the power output of the usb ports, however, I still can't figure out why it started happening only a few weeks ago...I'll need to check the usb hdd for errors/bad sectors because I remember reading some I/o errors in the logs twice few weeks ago
 

Vimes

Regular Contributor
I'm glad my issue brought attention to the power output of the usb ports, however, I still can't figure out why it started happening only a few weeks ago...I'll need to check the usb hdd for errors/bad sectors because I remember reading some I/o errors in the logs twice few weeks ago

Has this not been resolved for you...? I thought that it was ok...?
Sorry for detracting from your problem.

Not that it seems to be an issue with your 86U, hardware wise, but did you check to see if yours is till under the three years warranty...? Asus do provide three years guarantee with that router, at least mine has and claimed against after 2 years and 11 months.
 

thecheapseats

Regular Contributor
<snip> My go to SSD today is the smallest Crucial MX500/250Gb unit which clocks in at 70mW.
70mW "at idle"...

also, believing any of these chinese case/power supplies are 'certified' is silly... without running a bench test load on 'em (and also testing for mfg solder defects that put 5volts on a 3.3v TTL trace) - you don't know what you have...
 

OBENZ

Regular Contributor
Has this not been resolved for you...? I thought that it was ok...?
Sorry for detracting from your problem.

Not that it seems to be an issue with your 86U, hardware wise, but did you check to see if yours is till under the three years warranty...? Asus do provide three years guarantee with that router, at least mine has and claimed against after 2 years and 11 months.
Oh no it has been resolved as to why the cpu spikes and lgas we're appearing now what I can't figure out is why now...for now all is good the router is up for 6 days now and no cpu spikes or critical errors so far :) maybe a bad usb connection/lose connection was causing this
 

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