Earlier this week, halcyon33 brought up the issue of kernel latency spikes on Samsung laptops, which can make them unsuitable for real-time audio and other CPU critical tasks. Basically these are cases where a piece of code "monopolizes" the CPU, either because it is poorly written (some Samsung utilities) or because it is critical code which must complete without interruption (some hardware drivers). After several days of tests and trials and tribulations between halcyon and myself, I think we have some conclusions on how to reduce or even eliminate these latencies. Even though we are both on Series 7 (halcyon on NP700Z5C and I on NP700Z3A) we expect our findings to apply to other Samsung models as well. PLease see the Samsung Series 7 Laptops - 15.0" and 15.6" Models (NP700Z4 & NP700Z5) thread for our discussion, starting at this post. I have relied entirely on LatencyMon from Resplendence Software to diagnose. halcyon33 also used DPC Latency. As far as I can tell, the following are the biggest contributors to high kernel latencies (not in order of severity): 1) Easy Software Manager (ESWM). I believe what happens is, when ESWM checks for updates in the background, it causes Windows to rebuild its hardware device tree, which monopolizes the CPU for a few seconds. I recommend using ESWM after a clean Windows install to load drivers and necessary utilities (and load them in the correct order), then uninstall it afterwards. Use samsung.com to check for updates after that -- or simply install ESWM temporarily. 2) Easy Settings. This package includes seven different modules that manipulate hardware and the low levels of the Windows operating system. It provides some significant features (including Fn-keys), but unfortunately it is not very well implemented, and many of these modules monopolize the CPU while running in the backgound. I recommend installing Easy Settings, copying its folder (C:\Program Files (x86)\Samsung\Easy Settings), then uninstalling the entire package. After this, the Fn-keys can be activated by loading the EasyDisplayMgr module (dmhkcore.exe) using either a shortcut in the Start Menu-Startup folder or one of the Run keys in the in the registry. 3) Norton Internet Security. Never install Norton anything. High kernel latencies is just one more reason. Seriously. 4) Intel PROSet Wireless AND Bluetooth High-Speed drivers. Intel bundles a tremendous amount of bloatware with its WLAN and Bluetooth drivers, most of it running constantly in the background, causing kernel latencies to spike. Furthermore, there is an outright bug in most versions of the Intel 6230/6235 driver, causing it to drop WiFi a few mins after login: It will start happening if you ever disable/enable the Intel adapter in Device Manager. Then you'll have to disable/enable it on every reboot thereafter. Easy Settings' WLANStartup module exists to compensate for this bug, by performing disable/enable behind the scenes after user login. As long as you've never disabled the adapter in Device Manager (AND you don't have Easy Settings installed which disables/enables it behind your back), your network should be running promtply after login -- and stay connected. Of course we need WLAN and Bluetooth to work, so here is what I recommend: Do NOT install any of the full Intel PROSet Wireless/Blutooth packages, and do NOT install any of the following with Easy Software Manager: - Wiresless LAN driver - Bluetooth driver - Intel Wireless Display (maybe OK if installed later) Download and install Intel PROSet/Wireless driver version 15.2.0 from this Intel website. Make sure you download the DRIVER ONLY version, NOT the full software. The file is called Wireless_15.2.0_Ds64.exe (Google it if the link stops working). There are no options to choose, it just runs for a minute, displaying an animation. This should load drivers for your Intel 6230/6235 WiFi adapter which do NOT suffer from the problems described above. Windows 7 supports basic Bluetooth out of the box, including support for the Intel Bluetooth adapter. If you need Intel's newer and more elaborate Bluetooth features, just know that it comes at the price of somewhat higher kernel latencies. Note: I would love to hear from users of Broadcom WiFi how its drivers behave with regards to latencies. 5) Windows System Restore. This is the Windows feature which allows you to save Restore Points and roll back to them in case your Windows installation gets messy. This is a great feature, but unfortunately it causes high kernel latencies and lots of page faults. It can be disabled under Control Panel-System-System Restore. If you do disable it, I recommend using an imaging tool (3rd party, Windows WIM or Samsung SRS5) to backup your Windows drive at regular intervals. 6) Other Samsung latency suspects. In addition to the above, I would avoid installing the following utilities and bloatware, even though I have not seen hard evidence that they cause latency spikes. - CyberLink Youcam - CyberLink Media Suite - Samsung Recovery Solution 5 - Intel Management Engine/HECI (use Windows update to install just the driver, saves a lot of uncessary overhead) 7) Other Windows latency suspects. Even though I don't have hard evidence, I suspect some Windows 7 features could contribute to latency spikes. Particularly the media feaures, which trigger background tasks related to the MediaLibrary. For more suspects as well as a general list of bloatware that are candidates for removal, please see this recent post. Once these are removed, LatencyMon should be able to run for an extended time without excessive latency spikes. In my tests, I have run the Windows Performance Index Assesment and a network speedtest on speedtest.net. This lets LatencyMon run for a while and stresses some of the critical components that might trigger spikes. But even just sitting there doing nothing can suddenly show latency spikes, becuse it triggers some of those pesky background tasks that either run on regular intervals or when the PC is idle. In addition to making the system suitable for real-time tasks, reducing (or eliminating) latency spikes also makes it more responsive in general This is the first summarized write-up of our findings -- and we still have some tests to do before we can call this wrapped up. Until then, any comments or tests from others are highly welcome. It is important to point out that latencies are not a "black and white" issue: Less is better than more, but there will always be some; a single bad progam can completely jeopardize the system; but so can multiple programs or modules that are mere "demanding" which happen to trigger at the same time. That makes diagnosis rather difficult and time consuming. So please don't be too hard on us if your findings turn out differently. Just post it here so we can update the conclusions. Updates 2012-12-11: - As pointed out by Syl_M Intel has updated WiFi drivers out. - Prompted by a question from rhadoo, I finally got around to writing updates regarding alternative Easy Settings tweaks as well as info about Easy Settings 2.x. The post also contains a more comprehensive (and hopefully coherent ) installation guide with various links. Posted here in the thread (that was a link).