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XPS 15z Audio Crackling/Stuttering with network traffic over wireless (Latency Issue)
THREAD CONTENTS
This thread has grow over time and contains quite a lot of information. To make it easier to find specific information on this thread I have implemented a contents system which will allow you find information quickly. The thread has been split into sections and sub sections where appropriate. The contents uses Anchor points (thanks jimco for the tip!), so you can simply click on the section in the contents to jump to the section in the thread.
Sections:
- Summary Information of this entire thread
- What is DPC Latency?
- Newer Qualcomm Atheros Drivers vs OEM Driver
- Important information before replying to this thread
- All Information and evidence on the wireless latency issue
- How to test if you have wireless latency issues
- Workarounds/Fixes
- Dell's position on the situation
- Community Acknowledgements
If you haven't followed this thread through various developments since it was first published, take a second to read this summary. This thread has expanded massively overtime, so the information in its entirety might be difficult to take in without knowing all the facts.
The original problem described in this thread is regarding latency spikes over WiFi on the XPS 15z. The latency spikes are caused by unknown factors which have never been truly pin pointed to any certain area (and still haven't to this day). There are many areas which have been highlighted including Windows 7 and its lack of process interruption protection, Intel WiFi Drivers, Realtek Sound Drivers and other areas. A lot of community activity was involved in trying to get to the bottom of this problem. It was eventually discovered that the Atheros Ethernet Adapter could be attributed to the problem, after a newer Non Dell OEM driver was found for the Atheros 815X Family Ethernet Controller on a third party website. This driver was tested by several community members and it was found that latency spikes were reduced heavily. Since this point, it has been a community recommendation to install the Qualcomm Atheros drivers rather than using the outdated Dell OEM driver which is dated May 2011 for the Ethernet card in the XPS 15z.
There is far more to the situation than this, but it is a summarized version of the events that have taken place over the months. If you don't know what DPC Latency is or are unfamilar with the problem being described, take a moment to read through this thread, it is seperated into logical headings and groupings to make it easier to pick out the key information.
It is important to note that while the use of the official Qualcomm Atheros driver over the Dell OEM driver has helped people in this situation it is not a guarantee that it will solve you problem. Sadly many factors can cause latency spikes, the Atheros Ethernet Controller seems to be just one of them.
To understand DPC latency, its important to first understand what the two terms mean on there own:
A Deferred Procedure Call (DPC) is a Microsoft Windows operating system mechanism which allows high-priority tasks (e.g. an interrupt handler) to defer required but lower-priority tasks for later execution. This permits device drivers and other low-level event consumers to perform the high-priority part of their processing quickly, and schedule non-critical additional processing for execution at a lower priority. - http://en.wikipedia.org/wiki/Deferred_Procedure_Call
Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. Latencies may have different meaning in different contexts. - http://en.wikipedia.org/wiki/Latency_(engineering)
When there is high latency various problems can occurs, one of the main issues that are a side effect of badly managed DPC latency is audio problems. This can be often seen with multimedia content like music or video. When you have bad latency you will experience drop outs and degraded audio. To see the problem visually you can use a DPC latency analysis program which will tell you when you have bad latency.
What causes high DPC latency?:
Here lies the million dollar question, many factors can cause high latency. In a lot of cases it is usually down to poorly written hardware drivers that don't perform quick enough and cause lag between process execution. This then creates high latency and then will interfere with running processes. Sometimes this can occur very rarely and is acceptable in some cases, however it becomes problem if the DPC latency constantly spikes and can be reproduced in certain scenarios.
For the specific case of the XPS 15z, the driver that seems to be the most problematic is the Dell OEM driver for the Atheros 8151 Ethernet Controller, it is difficult to pin point causes of high latency, but the problem has been attributed to it. That is not to say that the Ethernet controller is totally blame. Without Dell investigating there own driver/hardware implementations we can't even conclusively pin point the issue.
The bottom line of the situation is however, the XPS 15z has very high DPC latency in a lot of scenarios.
3. NEWER QUALCOMM ATHEROS DRIVERS VS DELL OEM DRIVERS:
Disclaimer: These drivers are NOT official Dell OEM drivers and hence not certified by Dell. They are the OFFICIAL drivers from Qualcomm Atheros but have not been compiled specifically for Dell OEM. It is 100% safe to use these drivers, but if you experience any problems, roll back to the Dell OEM driver. It is likely Dell won't help you if you have problems with your Ethernet Controller when using these drivers.
After community testing of a newer 2.0 release of the Non OEM Atheros Driver found by Dell Community User richsark it has been found that the non OEM drivers certainly help the situation a great deal with regards to the latency issue. So if you having problems described in this thread, try following the Qualcomm Atheros driver installation steps in this section.
Another Dell Community member JimK157 has found Qualcomm Atheros have been releasing newer drivers for certain Atheros Ethernet Controllers on a regular basis, the AR815X Family Drivers which is what the XPS 15z has is part of these releases. The good news about this is there is now a dedicated page for these drivers which can be tracked:
http://www.qca.qualcomm.com/corporate/content.php?nav1=146
If you are already comfortable with updating drivers manually through device manager you can go ahead and download the drivers and manually install them, if you aren't sure what to do, follow these instructions:
- Go to the URL above
- Scroll to the AR813X AR815X Family Drivers section
- From the drop down menu select the "Windows WHQL Driver"
- The driver will be downloaded as a .rar archive, so you will need extraction software that can unpack .rar files. (Programs like WinRaR can do this)
- When you extract the archive to the specified location you will get a folder called "AR813x_AR815x_AR816x_[version_here]_WHQL". The version numbering will differ slightly for each driver release.
In the extracted driver folder there is a setup.exe, however due to this being the generic Qualcomm driver and not Dell OEM it is strongly recommended you only install the driver and nothing else. to avoid any performance issues or problems.
- Open Device Manager and expand the "Network adapters" menu
- Right click on your Atheros AR8151 Ethernet Adapter. It's name may differ depending on your driver version. Newer driver versions display the name as "Qualcomm Atheros AR8151 PCI-E Gigabit Ethernet Controller (NDIS 6.20)" older driver versions will display the name differently.
- Select Update Driver Software from the menu
- Select Browse my computer for driver software
- Now you will be asked to manually specify the location of the Ethernet driver. You will need to click browse to specify where you extracted the .rar archive to and navigate to this path Common_Dri\Win7_64 so device manager can locate the driver. When you have specified this path click OK and the driver will be automatically installed. If everything went OK device manager will state this in the window confirming a successful driver upgrade
To confirm the driver was updated to a newer version you can always compare the driver version/date to the previous version prior to updating. Making a note of the driver version/date is a good indicator.
4. IMPORTANT INFORMATION BEFORE REPLYING IN THIS THREAD:
Before replying to this thread make sure you are reporting the right problem. It has become apparent that the Dell XPS 15z has different audio problems which have caused some confusion in multiple threads. This specific thread is for people that are having problems with audio when using the WIRELESS connection, which happens to be related to DPC LATENCY.
If you experience problems with audio when using the Ethernet connection or a different scenario, do not post in this thread, you have a different problem. We are trying to keep the different audio issues separate, so Dell and other community members can understand the different issues.
Remember, this thread is for audio problems when using the XPS 15z over wireless only where massive latency spikes occur as shown below:
Please Note: Disabling the Atheros Wired adapter does not solve this problem, this suggestion is for a different problem but will make no difference to the problem described in this thread.
5. EVIDENCE AND INFORMATION REGARDING THE WIRELESS LATENCY ISSUE
a. Summary of the wireless latency problem
To summarise previous threads, many community members from the Dell Community and other forums have reported audio issues on the Dell XPS 15z for a while. This specific audio issue is regarding the Intel Centrino 6230 N Wireless Card in the XPS 15z.
When a wireless connection is active and network traffic is generated, audio glitches will occur on the XPS 15z. These glitches range from audio crackling, degradation and even audio playback being distorted. In some cases this issue can go unnoticed, however the underlying problem is always present.
b. Evidence of latency spikes on the XPS 15z
From reading various articles and other forum threads on this issue, I am pretty certain it is something to do with Wireless. Dell has stated in the past that the Centrino 6230 N card is not at fault for the audio issues, however I believe they are wrong.
Thanks to another community member (ShonkyCH), we have pretty hard evidence that the wireless card is causing these issues. If you observe the DPC latency on the Dell XPS 15z while on wireless you will find that you get very large spikes when an average amount of network traffic is generated. First some evidence of the problem:
EXHIBIT A: Performing a Latency test in real time.
The video below demonstrates the problem in real time. In this test I performed a simple action of the typical home user, by pulling a 720p Movie File from my NAS server. To make everything fair, here are the variables in this test:
- Router: WNR3500L V1, running DD-WRT K.26 Build 14929
- Wireless Speed: Wireless N 2.4 Ghz (Single Band)
- NAS Server: HP ProLiant Microserver N36L (Integrated Broadcom Gigabit Ethernet Port, connected to a Gigabit switch)
If you cannot play the embedded video click here to view the video directly.
The latency graph explained:
From the video above you have observed latency spikes when a decent amount of network traffic is generated. Below is more information on the latency test I performed.
Bar chart graph key:
- Green Bars - Good
- Yellow Bars - OK
- Red Bars - Bad, will cause audio drop-outs
Latency when network traffic is generated:
The next screenshot below shows the latency when network traffic is generated. Exactly the same test was performed as seen in the video to produce these results:
As you can see the latency is completely spiking off the scale. This was taken after I let the film play for a few minutes.
What this means in graph form is a visual representation of why the audio issues are happening. These latency spikes are (I believe) the primary contributor to the following audio issues users are having:
- Audio crackling (Constant under network load)
- Audio quality being degraded (Occurs in some cases)
- Audio playback plays as if the speed was being slowed. (Briefly happens, generally when using an Internet browser. It seems certain processes affect audio playback)
First of all you need to be on a Wireless connection only. Any wireless connection will do. It can be any speed either G or N. Then you can do a couple of things to see if you have the latency problem reported above. The easiest way would be to download a DPC Latency Checker program and observe the latency for yourself when you generate network traffic.
- Download the DPC Latency Checker Program used in this test (http://www.thesycon.de/deu/latency_check.shtml)
- Save it to a easily accessible location on your XPS 15z i.e. Desktop, Downloads Folder etc.
- Go to the location you saved the download and open the executable dpclat.exe (It doesn't require an install it is a pre-compiled program)
- Close any network related programs like Internet Browsers, Torrent Applications etc and let the program analyse your DPC latency.
- Now generate network traffic, visit some websites in your favourite Internet Browser, perform general internet activities. If you have a NAS server (or similar setup) you might also want to perform the test above to see for yourself.
Another simple test to actually hear the audio glitches is to open your favourite music player i.e. Windows Media Player, iTunes, Zune, VLC etc and play some tracks in your playlist, now do some internet related activities, browse some web pages, just do some general normal day to day internet related actions. In a lot of cases you will find as you browse different web pages the audio of your music tracks playing becomes degraded, in most cases you will find either the audio crackles or the audio seems to slow down as if the speed of it was slowed by 2x, then once whatever browsing activity has finished the audio will be fine again. This happens with both the XPS 15z speakers and with headphones directly plugged into the headphone jack.
It is important to point out that the Ethernet Connection does NOT suffer the same DPC latency spikes and no such audio issues occur with anything network related over ethernet. Latency is far better and you will mainly find Green bars, with a few yellow bars, no red however.
7. WORKAROUNDS/FIXES TO THIS PROBLEM
Using the Qualcomm Atheros drivers for the Ethernet Controller seems to help a lot of people that experience large latency spikes in certain situations. You can find out how to obtain and install the Qualcomm Atheros driver by clicking here. From testing it has performed much better than the Dell OEM driver and has reduced latency spikes in most cases. It is not however the magic fix to the problem. Latency spikes still occurs, however they become far less common and not as severe. It has been tested by members of the community and has yielded good results, but again there are no guarantees of its success rate with different users.
Any workarounds here are classed as legacy workarounds as they are not as effective as the recommended workaround and have been hit and miss for a lot of people.
Creating a custom power plan:
A workaround has been found thanks to AKTundra. This workaround involves creating a custom power plan in Windows 7 with a couple of modified settings related to processor power management.
- In your Taskbar (Bottom Right) right click on your battery icon and select power options. If you don't have system icons enabled you can access the power options via Control Panel. i.e. Start > Control Panel > Hardware & Sound > Power Options
- The power options window will appear, on the left hand side select create power plan.
- Give your power plan a name e.g. Audio Fix, you can base it off either Balanced or High Performance you can also leave the on battery/plugged in settings on their default values. Click create to create the new power plan
- The power plan you just created should be now in the Select a power plan menu. Find it and then click "Change Plan Settings" then click "Change advanced power settings".
- A smaller window will now appear with the option of changing more advanced power plan related settings. Scroll down to "Process power management" and expand the menu, now expand the "Minimum processor state" option. There will be two values, on battery and plugged in. By default these will read 5%, you will need to change both to either 50% or 55%. Once the values have been changed click apply and click OK to close the advanced options window. You may have to increase these values further depending on your environment and setup.
Hardware replacement/Wireless speed adjustment:
One solution that has been documented by ShonkyCH is getting the wireless card replaced. He had his wireless card replaced by Dell which ended up being a Dell branded Broadcom based device. The good news was it fixed the problem, the bad new is the replacement card lacks several features of the Centrino 6230N and hence isn't really a great solution. I personally won't accept this as a fix and hence continue to keep various threads regarding audio issues on the XPS 15z alive until I get some acknowledgement from Dell for everyone in the same boat regarding audio issues.
An interesting point that was discovered through experimentation is it seems latency issues seem to be more of a problem when on higher speed networks. E.g. Wireless N compared to Wireless G. A few people reported audio issues occur far less when on a Wireless G network compared to a Wireless N, where throughput is far less, however Wireless G speeds still produce latency spikes contributing to audio issues.
A final (last resort) workaround is to use Ethernet if possible. This obviously isn't a solution, but if you have access to an Ethernet port at Home/Work try and use it. I know, its not a great solution, but you might have to compromise for now until this problem is sorted.
8. WHAT IS DELL'S COMMENT ON THIS PROBLEM?
A few of us have privately messaged moderators on this forum and/or contacted Technical Support about this issue and have received the following comments, here's a summary of what Dell have said about this issue:
- Engineering state its a Windows 7 problem, due to lack of processing interruption protection
- They do not believe the Centrino 6230 N is at fault.
- Technical Support agents don't except the problem either and have even blamed networking hardware such as the customers router.
- Dell agents have scheduled service calls changing pieces of hardware of a few community member's XPS 15z including Motherboard, Speakers and Wireless card. All replacement Centrino Wireless card variants have had the same problem, speaker/motherboard replacements have been ineffective.
A big thank you to everyone who has contributed to this thread. This thread stands today because of the community and everyone who helped test, contributed important information and shared there knowledge on the situation. Without the community this thread would not be as comprehensive as it is now. Well done everyone, this was truly a forum community effort to compile this information together!
James2k
278 Posts
0
February 6th, 2012 12:00
I've just updated the original thread with video evidence of the problem. I thought it would be easier to see this problem from just a few screenshots.
@shiva.sadhashivan.
Sorry to hear your XPS 15 has this problem.
Yes the problem is solved if I use the wired adapter. If you completely disable the wireless adapter via Fn + F2 (Keyboard shortcut on XPS 15z) or via Device manager you will find you will not get any audio glitches. I performed the same latency test above with just the wired adapter and found the latency to be much better and did not see any red spikes.
Just a general note that's not directed at you but for general information. Some threads suggest disabling the WIRED adapter to solve audio problems. I'll repeat it again this is not the same problem and disabling the wired adapter will do NOTHING in this scenario.
James2k
278 Posts
0
February 6th, 2012 13:00
@BRAHMOS-IN
Hi thanks for posting your findings. That's another variant of the Centrino card that is affected we can add to the list.
I spent some time reading that article you posted earlier this afternoon, it was a great find thanks for posting it. It is certainly a possibility that the design of the XPS 15z could be a issue, but again I want to be careful here and not speculate too much without knowing all the facts.
iAMjason
9 Posts
0
February 6th, 2012 19:00
@James2k
A few months ago, I had an XPS 15 which I later traded for my XPS 15z (the one I'm using now). The XPS 15 had the same Centrino 6230 card as my XPS 15z and never had the crackling audio problem on a Wireless-G network. However, I never had the chance to test it on a Wireless-N network to see if greater bandwidth was causing the crackling audio.
Also, do you think that this is really a hardware design problem? I think that this problem varies based on the computer. To measure latency, I did a step-by-step test on my 15z and a friend's 15z (that had similar specs). I found that my computer had about 8-12 thousand nanoseconds of latency, whereas my friend's computer had only 4,000 seconds.
James2k
278 Posts
0
February 7th, 2012 02:00
@iAMjason
I have noticed a few XPS 15 users have reported similar audio problems to the XPS 15z but Its unclear if its the same issue. Right now it seems this specific latency issue is confined to the XPS 15z. I know many laptops and even desktops will experience latency issues, but I have never seen latency spikes of this magnitude on any other machine.
From what I've read and using general knowledge. It is likely the latency problem will not occur as much/the effects won't be as bad due to throughput being far less on Wireless G compared to Wireless N. Though Wireless N is not to blame. Modern machinse such as the XPS 15z should be able to handle increased throughput no problem.
I would like to think that the general design of Dell XPS 15z is not the cause but you have to consider every angle with a problem like this as there are many factors. Thanks for testing the latency with another XPS 15z, the fact that the latency varies is probably to expected as a number of factors including, Wireless speed, amount of network traffic etc will produce different results, but it is interesting to find your friends XPS 15z had a lower nanoseconds of latency.
When I have more time I plan to test the latency on the XPS 15z further. My main two tests I want to run is running the latency test when the XPS 15z is running on default startup/services to see if I can pin point any specific program/service causing spikes. Another test that I want to carry it out is the latency on Wireless G vs Wireless N. I have been on Wireless N for a year or so now but do have some spare routers lying around which are Wireless G spec and I could setup a separate subnet on my network for this test.
When I get more time I'll carry out these tests and report back.
shiva.sadhashiv
4 Posts
0
February 7th, 2012 03:00
Hi All,
I have been talking to DELL Tech Support over the last few days about my problem and now after various rounds of testing, they have accepted the fault and have are now ready to replace my Motherboard. Do you guys think this will help?
Thanks and Regards,
Shiva.
ShonkyCH
48 Posts
0
February 7th, 2012 03:00
Read the threads and you will see that our answer will be a "likely not at best".
They gave me a whole new machine at once stage and it had the problem out of the box. So unless a new machine has an upgraded motherboard/wifi card it will still have the problem. It's not a hardware failure from all accounts so far. Unfortunately Dell do not seem to even acknowledge the problem and insist on going through there standard cheat sheet for fixing issues i.e. upgrade drivers, full reinstall, replace hardware etc.
shiva.sadhashiv
4 Posts
0
February 7th, 2012 03:00
Thanks for the quick reply, ShonkyCH and Yes, I expected that. Even now, before giving away my laptop for hardware replacement, I have asked them in the first place that whether replacing motherboard will solve the problem or not and have they been successful doing that with other users. But it is quite frustrating to note that they are not ready to accept the problem despite so many of us experiencing the same. I think nearly 95% of all XPS laptops are affected and perhaps only 50-60% of them reported to DELL. Is it anyway possible to take this issue to the Next Level? After all we did not get the laptop for Free.
James2k
278 Posts
0
February 7th, 2012 04:00
Myself and a few others have recently been communicating with Terry B (Dell notebook Liaison) about this problem and what Dell are doing about it (See the post by iAMjason on page one of this thread). To summarise the response. Dell is aware of the issue and its been reported to engineering which have apparently been reading these posts. Though it seems engineering are taking a firm stance that Windows 7 is to blame.
I do not entirely agree with this statement and hope the information in this thread shows that it is more than just the operating system that is at fault. It may well be that Windows 7 is PARTLY to blame, but I don't think its the primary contributor to the latency issue.
shiva.sadhashiv
4 Posts
0
February 7th, 2012 04:00
Great and good to know that James. I will read the posts and have been doing it as and when I get time. But if DELL is so confident that Windows 7 is to blame, then why can't they simply install Vista or XP on these (if it is supported well enough) and try to prove that they are right? Did they do that already and also have you guys heard of anyone else reporting the problem who is using Windows 7 and not DELL? At least I have Windows 7 Professional on my office PC which is Lenovo and that doesn't seem to have any problem whatsoever. The only difference in this one being No NVIDIA and webcam. Also I have Intel Centrino Advanced-N 6200 AGN wireless adapter.
James2k
278 Posts
0
February 7th, 2012 04:00
All of the drivers for the XPS 15z are for Windows 7, there are no drivers for Vista or XP so its not possible to test another version of Windows reliably. However installling a Linux distribution is a option to see if audio issues still occur. Regarding a non Dell laptop and the Intel Centrino 6230 N, I have personally not seen any reports of problems so this may lend credibility to the fact Windows 7 is not problem.
AKTundra
7 Posts
0
February 8th, 2012 15:00
My daughter is having the same problem with her XPS 15z when she listens to audio over our wireless connection (wireless N). She tried Dell support and got no where with India tech support supervisor. He wanted her to pay $170 for a one year software contract to periodically clean her registry. He said it was not Dell's problem.
After much internet surfing I came upon a potential fix, not a solution mind you, but it seems to be working for her.
We downloaded the DPC latency program and while initially in the green, it went immediately into the yellow/red when she watched netflix just as you are experiencing.
I then went to control panel / hardware and sound / power options. Then for the selected power plan (I set up custom plan 1) click on change plan settings and then click on change advanced ower settings. Then click on processor power management and click on minimum processor state. Now you will probably see 5% for both battery and plugged in. I changed these to 55% and now when she runs netflix it stays all green.
I don't know if this will now cause other problems, other than probably reducing battery life, but it seems to solve her audio distortion.
ShonkyCH
48 Posts
0
February 8th, 2012 15:00
AKTundra
Cleaning the registry ain't gonna do it. Some people have experienced it with bare installs. I have verified it occurs with a brand new fresh image from the Dell recovery partition. If the registry was "dirty" then it's being provided "dirty" by Dell and hence should be their problem. However I think we all know that's not the issue.
Your work around sounds promising. Did you try any other values between 5 and 55%?
Yes I would expect battery to be significantly impacted. I assume this is clock speed or similar although I'd be surprised if it can drop down as far as 5% of maximum speed. That's only about 150MHz (can't remember the min max speeds). The Intel turbo boost doesn't tend to show speeds below the nominal maximum though.
Also if the device is running more continuously, I'd expect more heat to be generated resulting in the fans operating more further reducing battery life. Also that heat is not good for electronic components in general. Roughly half the life for every 10C increase in temp.
If setting to 10 or 15% was enough that might be an acceptable solution at the expense of some battery life.
NB: All my testing so far would have been on AC power but if both are set to 5% then they should operate the same.
AKTundra
7 Posts
0
February 8th, 2012 17:00
The registry answer from Dell India was clearly not valid. Her registry was no more corrupt than an average computer that has been in use for a couple of months with various software installs and uninstalls. I agree with you.
No I did not try any other numbers between 5 and 55. I did note that on my 6 year old XPS 1730 the default settings for the "high performance" plan were 100% plugged and 50% battery. This is the setting the laptop has been set to since I got it . Probably part of the reason this laptop runs so hot..of course two 9800M video cards in SLI aren't helping the heat issue either. LOL.
Battery life is a non-issue on that machine since without its 'brick' transformer plugged in battery life is like 20 minutes.
I will have my daughter try lowering the settings and see what the sweet spot is. Before this change her laptop was very cool. It will be interesting to see if it starts to heat up at the 55% setting.
If this solution works, it is simple to put into effect as long as it doesn't create other equally or more bothersome side effects.
Cheers
ShonkyCH
48 Posts
0
February 9th, 2012 03:00
Ok. So I tried playing with the minimum CPU state. Monitoring using CPU-Z though there doesn't seem to be a direct correlation
The slowest CPU-Z ever reported was 800MHz (8 x 100MHz) and the maximum was 3300MHz (33 x 100MHz). So 800 is about 25% of maximum speed.
My testing showed there didn't seem to be any noticeable difference between 5 and 25% in terms of red bars in DPC latency.
40% was better in terms of red bars but still quite a lot. CPU frequency was still dropping to 800MHz
Around 50-55% is where it really starts to kick in and help a lot. Mostly yellow/green bars and all less than 4000us (small red readings every now and then). Probably this would be good enough assuming battery life wasn't significantly worsened. In this setting CPU-Z still reported 800MHz speeds but they seemed less frequent and generally would sit on 1600MHz or higher. I didn't see a correlation between bad latency and 800MHz though.
At 100% it was much better and green nearly all the time with an occasional yellow. No red ever that I witnessed. Processor still dropped back to 800MHz
At the higher minimum percentage state, the fan did seem to be running a bit more than normal but not excessively as I had suspected in might end up doing. It definitely seemed to get hotter with it on my lap.
So to summarise, increasing minimum process state does help but I'm not really sure what that really does and what adverse effects it might have. The most likely is worse battery life but would require more testing and timing of battery life.
AKTundra
7 Posts
0
February 9th, 2012 21:00
After more research I am now confident that the only negative byproduct of increasing the minimum power setting is some reduced battery life and increased heat. The minimum processor state does in effect change the CPU frequency (speed). Many people seem to believe if you set min to 0% and max to 100% the computer will pick the best speed for the tasks at hand. Clearly this isn't the case from my observation so there must be a 'ramp up' effect or something. At 50% my daughter's problem is gone and her computer did not get significantly hotter.
I am at a loss as to why CPU-Z is reporting speeds below the minimum setting.
I also found an interesting article on various things you can do to improve the use of your computer for an audio device (it is written for windows 7 but is applicable for vista as well):
www.native-instruments.com/.../Windows+7+Tuning+Tips+for+audio+processing
One of the last 'fixes' mentioned is to set the minimum processor level to 100% and then lower it if needed due to heat or battery life. The article also references a good monitoring tool to help identify which processes are potentially causing latency issues if even at 50% you are still getting several yellow or red bars.
Hope this helps!