PC-VCR TimeShift problems on HT?

[virgildlv]

I had already setup my G450eTV on my system with P4 1.8A and tuning, recording and timeshift went OK.

I recently upgraded to P4 2.6C on the same motherboard. I enabled HT, allowed XP to configure changes, and replaced MtxCPUInfo.dll with the file provided by Matrox.

However, Timeshifting does NOT work anymore. When I start it, the system starts "preparing", then reboots! I have tried uninstalling and reinstalling drivers (5.82) and vidtools (2.10a), with the same results.

Any suggestions?

[Brian Ellis]

Try it with HT disabled. HT can do all sorts of unpredictable things to non-HT software and, in any case, slows them down, because the same instructions are handled twice in the CPU.

[VJ]

Originally posted by Brian Ellis
Try it with HT disabled. HT can do all sorts of unpredictable things to non-HT software and, in any case, slows them down, because the same instructions are handled twice in the CPU.

All hyperthreading does is utilize the unused execution units for another thread.
If programmes behave badly in hyperthreading, they should exhibit similar issues in regular SMP platforms.

As Brian said: try it with HT disabled. If it does not occur, then it means the program has issues with simultaneous threads. If it still occurs, there must be something else going wrong... (DMI pool ?)


The potential slowdowns caused by hyperthreading stem from the contextswitches the CPU might have to perform, but if I'm not mistaken, recent HT versions detect this. It also helps to have a HT-aware OS in this context (e.g. W2K sees them as real independant CPUs, whereas XP knows that they are not mutually independant).
I'm not sure, but I think a hyperthreading CPU uses the same HAL as a regular one... If not, this might also be a cause of problems...

Jörg

[virgildlv]

As suggested, I set Hyperthreading to DISABLED in the BIOS.
After this, I reboot XP and checked the WindowsTaskManager - Performance tab & found only one window in CpuUsageHistory meaning HT is indeed disabled in the OS.
(But please note that in ControlPanel - DeviceManager, it is still listed as ACPI Multiprocessor PC.)

I ran PC-VCR with the HT ready MtxCpuInfo.dll - still the same problem when I start TimeShifting: the system starts "preparing", theres some HD activity, PC-VCR crashes and the system reboots! NOTE that the other recording functions still seem to work - only TimeShifting is screwed up.

I put back the original non-HT MtxCpuInfo.dll in the Matrox Video Tools directory - and its back to the old "An unrecoverable error has occured. The application will be terminated." error message and PC-VCR doesn't run.

So DISABLING HT DOES NOT FIX THE PROBLEM! Help!