View Full Version : DMK31 image freezes

May 18, 2010, 00:08:44
please excuse my approximate english ;-)

i have a problem with my DMK31 USB2 on ICCapture 2.1 : I use it for several months without any problem, but i changed my laptop today, and i have somes freezes on avi record, but this is obviously not a concern of HDD framerate.

I explain :

- With my old laptop (HP 6910P with 5400 rpm 80Go HDD, with Vista 32), all was ok, 30 frames/sec was recorded on the HDD at 1024x768 without loss of frames.

- With my new laptop (Dell Vostro V13 dual core with 2Go Ram, 7200 rpm 320Go HDD, and the same Vista), on 1024x768 screen always freezes when i record an Avi, it freezes about 5 sec per 10/15 sec recorded, image freezes and HDD record stops. It freezes on 30 fps, 15 fps, 7.5 even 3.5 fps !!! On the avi, nothing is recorded when freeze.

- If i use ROI mode, i crop the screen only a bit, i/e 1020x764, so there is no freeze and the Avi recorded all the frames (900 frames on 30 sec and 30 fps).

Then I tested the DMK and ICCapture on my workstation, and there is no problem to record at 1024x768.

On the Dell Vostro i tested with the battery cell or the external power, problem is the same. On USB2 port, there is only the DMK.

DMK has no problem, ICcapture has no problem, i think the problem is somewhere on the Dell Vostro but where ? Vista is exactly the same as on the HP 6910P.

HDD problem ? I don't think so
Memory problem ? Processor problem ? Screen or graphic card problem ? Graphic configuration ?

Why when i use ROI and few pixel crop, all remain ok ?:question:

Thank you for your help

Stefan Geissler
May 18, 2010, 09:42:39

I suppose the problem is the C-state change, part of the power management, of your CPU. If the CPU load is below ~20%, then the CPU slows down and also USB, FireWire and eSATA will be slowed down. This results in many frame drops for the USB driver.

If you use ROI, then the CPU load is higher, because the ROI is done by the CPU.

First off all, check the power / energy options of your laptop and set them to the highest possible value.

If you work with Windows XP, you may use the nice SpeedSwitch XP program to create a power profile. The program can be downloaded from http://www.diefer.de/speedswitchxp/. You should disable the promote and demote of C-States and set a high C-State.

This program wont work in Windows Vista or Windows 7. You may search, whether you have some BIOS settings, that may avoid the problem.

A solution I use in Windows 7 Core 2 Quad is a little program called "cpustress" You may can find it in the internet, I have no download link right now. With it you can create ~20% or more CPU load until you receive images again.

May 18, 2010, 19:06:24
Thanks Stefan for your help.

Perhaps processor is the way. I will check on Bios if some option exists.

Problem could it be on graphic card too ?
This morning i tested it with a MKV movie (HD 1080p). On the HP6910, this movie is full ok, but on the Dell Vostro, the MKV always freezes 1 per 5 seconds.

On the Vostro the graphic memory is common with the RAM, so there is another way for the problem.

I first will se the C-state and i will tell you the results.

For the moment, the problem is solved with ROI mode and just few pixels croped:
- 1020x768 is OK.
- 1024x764 is OK.
- 1024x768 is not OK !


EDIT : i just tested some options on the Bios : Speedstep off, energy saving off, etc.. with no result
Energy options are on highest values on Vista.
I will test with CPUstress.

To be continued...

Stefan Geissler
May 19, 2010, 15:06:31
There may is a "C-State bla bla" that can be disabled.