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ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
06405 Core Feature Always Oct 11, 2016, 03:52 Oct 11, 2016, 07:14
Tester Zelda189 View Status Public Platform
Assigned To Resolution No change required OS
Status [?] Closed Driver
Version 0.172 Fixed in Version Build
Summary 06405: Multithreading or Hyper Threading is Missing Command-Line
Description Typing the Command Prompt "mame -mt" and the following the error message:

Error: unknown option: -mt
Steps To Reproduce
Additional Information Multithreading is required to run the faster Games.
Some HT CPUs are requred by -MT Switch

Sega Lindbergh
Ghost Squad Rev A
and others.
Regression Version 0.172
Affected Sets / Systems
Attached Files
png file icon Multithreading Removed 0.172.png (601,788 bytes) Oct 11, 2016, 03:52 Uploaded by Zelda189
There are no relationsihp linked to this issue.
User avatar
Oct 11, 2016, 05:17
edited on: Oct 11, 2016, 05:22
-mt (-multithreading) is gone from source. It caused numerous graphic issues with many drivers and until a solution that does it correctly is developed, the command will not be returning.
Examples: and other bugs linked to that.

No amount of trickery will allow any current computer to run any of the games you mentioned such as Naomi/Naomi 2/Atomisware/Lindbergh driver or similar game at any playable speed. You are way overstating this command's abilities.
If you value that command, you'll need to stick with an older version of MAME which has it present or upgrade your machine. The best you can shoot for right now is a good i5 or i7 with as high Ghz as possible but then then, again, you'll not be able to play most of those later drivers.

Closing with No change Required.

User avatar
Oct 11, 2016, 07:14
As stated on the wiki page:
Does MAME benefit from SMP (symmetric multiprocessing) / HT (Hyper-Threading) / dual cores?
No. Previous versions of MAME included a -mt switch which allowed some tasks to be threaded off for use by SMP or multicore systems. However, as of MAME 0.173 this switch has been removed. The benefits from this -mt switch were relatively small, because accurate emulation such as MAME strives for cannot easily be broken up into parallel subtasks (it would be like trying to have a baby in one month by impregnating nine women). We also found that this particular implementation of the -mt switch created a lot of errors. There were exceptions of course, but MAME will have to support them via some new mechanism in the future since the -mt switch has been removed.