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What causes the periodic performance spikes that are seen when doing computationally expensive array processing on the Nexus 4?

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http://stackoverflow.com – I'm new to threads (don't kill me for my implementation below :) and I need to do multiple blurring passes of pixels on a separate thread (see below). It's not the most efficient implementation of box blur (it's from Gaussian Filter without using ConvolveOp) but the performance spikes don't occur on the Nexus 7 tablet but they do occur on the Nexus 4 phone. I've posted my testing sample (running on Android 4.2 - see below). I don't think it is caused by the GC thrashing the memory (it doesn't coincide with the spikes). I think it might be something to do with cache locality or hardware mem (HowTos)

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Submitted by linuxletgo on 01/13/2013 – Made popular on 01/13/2013

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I have used BT on a vm for school many times so I decided to install it on a old laptop that was previously running vista and blue-screening. I installed BT5R1 via live usb. Everything installed correctly. But now when I start up the GUI the cpu continuously spikes at 100% every 10 or so seconds. It also sometimes spikes to 100% for 10 seconds, then drops back down for 10 seconds.

I have a server which is idling below 5% cpu load most of the time, except from a few times a day where I can see some minor cpu spikes. I found out about this by using PRTG.

How can I find out what process is causing the cpu spikes?

When ever I am listening to podcasts etc in the car and have the charger plugged in I will get annoying spikes in the sound unless I keep the volume really low or unplug the charger. Tried two different car chargers...same result. Anyone else have this issue?

I unrooted my nexus 4 weeks 2 days ago

I was never getting great performance with any rom. All would eat up my ram. I know Linux is supposed to control this but all the roms I tried never did a good job. Unrooted my nexus and performance is definitely better.

Sent from my Galaxy Nexus using Android Central Forums

Google’s Nexus 4 isn’t just any Android device; it’s the flagship Android device. It’s the only current smartphone that wields the premium Nexus name, and the only handset running Google’s latest iteration in Android, version 4.2 Jelly Bean part deux. Moreover, the Nexus 4 undoubtedly serves as the most highly anticipated smartphone of 2012, and quite possibly the most rumored.

Btrfs performance issues 2 weeks 3 days ago

cfr wrote:So how does it test if it can achieve a good compression ratio?Since performance is also bad, when compression is disabled it doesn't matter. i guess i should edit my first post it would be interesting to know if somebody else sees this cpu-spikes when copying big files.

ccc1 https://bbs.archlinux.org/profile.php?id=24987

2013-05-02T01:14:11Z

On my dual-socket server, I occasionally see that CPU usage absolutely spikes to 100% on all cores for about 5 seconds at random periods during the day. It happens about once or twice a day. The only reason I found out about this was due to the logs of another application I'm running. What tools does Windows Server 2008 R2 have that will help me catch exactly what is doing this?

Google’s latest Nexus-branded hardware went on sale in Europe today. The Nexus 4 smartphone and Nexus 10 tablet were both due to be available today on the Play store, alongside the refreshed Nexus 7 tablet. But it appears that the newest Nexus hardware is selling out fast.

The LG Nexus 4 is either a great new flagship, or a half-baked device missing several important features, depending on who you ask. Unfortunately it looks like the latter is getting a little more ammunition as it’s recently surfaced that the Nexus 4 has no USB OTG (on-the-go) support. USB OTG cables allow users to connect a mouse, keyboard, flash drive, etc.