@urlwolf: Thanks for this interesting discussion.
..I now belive HP is the most incompetent company I know...
-urlwolf
In defence of HP, I would suggest that it probably only
looks that way to you because of your (this) bad experience.
I had the same sort of experience with DELL support when trying to renew a maintenance contract for a laptop bought in one country (UK) but being used in another country (NZ) - the latter being where I needed the support. I eventually got there, but I shudder when thinking about it, even now, and "incompetent" was one of the most polite of the epithets/expletives I used.
In reality, both HP and DELL have amazingly good pools of highly-skilled and competent technicians, but they are isolated/insulated from the formalised support
business process. They had to be isolated because they are relatively few in number, and are only assigned to work on 2nd level support issues. The 1st level support is done (or attempted) by the people you get into contact with via their Support centre (the customer-facing part) - and the first contact you make there is likely to be more of an administrator or problem-router than a pukka support technician wiz.
For what it is worth, and simply in the hope that it might be of use/help, here are some of my experiences when trying to sort out some annoying DPC latency issues on my HP ENVY 14 laptop (ATI Mobility Radeon HD5650 1GB Dedicated Graphics) - operating system is Win7-64 Home Premium.
The latency seemed to be adversely affecting the quality of the graphics display (I have mostly fixed that) and the sound output (still fixing that):
- 1. I reckoned that there would be a techo wiz somewhere in HP who would know exactly what my laptop problem was caused by and whether it could be fixed, and if so what the appropriate/necessary fix or workaround was. I also reckoned that my chances of getting to actually talk to that person or having them focus on this problem for me were probably pretty bleak.
What I knew was that these wizzes would likely as not often be busy helping out in support forums, so I googled "DPC latency" and also googled for forums referring to HP ENVY 14, ATI/AMD Mobility Radeon HD5650, and other support forums.
Some examples (links and tools):
- 2. Getting an upgrade to the display driver was a real headache, and I posted about my solution here: Problems with AMD/ATI Radeon HD 6500M/5600/5700 Series GPU driver/software
- 3. Tweaking and experimenting all standard Windows graphics/animation features (e.g., switching them on/off and seeing what the results were).
General result: using the CPU for full graphics output (instead of the GPU) improved the quality of the display for written material.
- 4. Tweaking and experimenting with the settings for the AMD/ATI Radeon HD 6500M/5600/5700 Series GPU driver.
General result: using the GPU for full graphics output (instead of the CPU) reduced the graphics image quality but speeded up the animation (reduced latency).
- 5. There is an option in Google Chrome chrome://settings/, under Show advanced settings-->System to Use hardware acceleration when available. I expect there may be similar settings in the other browsers, but am unsure where.
So you can see that for graphics there were trade-offs there. Probably the trade-offs will take the general form of: optimising for good graphics output will result in sub-optimal audio output, and
vice versa.
For audio, I am still trying to get to grips with understanding what automatic priority interrupts from what device/driver are being assigned precedence in the queue over the audio output, but the
DPC Latency Checker tool seems to be proving quite useful there. The WiFi network adapter looks like it might be causing some of the problems in my case.
Example of
DPC Latency Checker tool in use (the notes in the image might be useful):
