Problems and Solutions: Kega Fusion is only 30 ~ 32 fps in full screen in Windows 8.1

This is a problem that affects the emulator Kega Fusion in its latest version (3.64) and possibly earlier. In my case, everything was fine in Windows 8, but to make upgrade for Windows 8.1 the problem appeared. No matter what settings are made in Kega Fusion, when switching to fullscreen mode the emulator can not display more than something between 30 and 32 frames per second.

After many failed attempts, I ended up finding the solution here. Both the first and the second method works. I reproduce here the solution, Just in case the original source end disappearing:

Microsoft uses some compatibility in Windows 8 and Windows 8.1 for all DirectDraw (DirectX 5-7) applications running in fullscreen mode.
Compatible called DisableMaxWindowedMode, because of this compatibility fullscreen mode does not work properly.

Flip flags are ignored in this mode, but the flip will still occur resulting in low FPS. Because of this, you get no more ~ 33FPS.There are 3 options how to return the normal FPS in fullscreen mode:

1. Using the Microsoft Application Compatibility Toolkit

  • Install Microsoft ACT –
  • Run the Compatibility Administrator (32-bit)
  • Select New Database (1) and press Fix
  • Fill in the vendor name and the program name, as well as the location of the program. Press next.
  • Press Next again.
  • Select fix DXPrimaryEmulation
  • Click Parameters, enter: -DisableMaxWindowedMode and press OK.
  • Press Next.
  • Press Finish.
  • Press Save, select the database name and save location.
  • Press File – Install

30 FPS before fix –
120 FPS after fix –

2. Use a modified ddraw.dll

I disabled in ddraw.dll problematic compatibility DisableMaxWindowedMode

The archive contains two dll for Windows 8 and Windows 8.1 – (mirror link)

Installation: copy ddraw.dll in the game folder.

Note: Fraps does not seem to work with ddraw.dll proxy, use other programs to monitor FPS, such as MSI Afterburner OSD.

31 FPS before fix

60 FPS after fix (Vsync)

201 FPS after fix (No Vsync)

3. Call SetAppCompatData

If you have the source code, you must use the function – SetAppCompatData to disable DisableMaxWindowedMode.

For example:

HMODULE hDDraw = LoadLibrary(_T(“ddraw.dll”));
SetAppCompatDataFunc SetAppCompatData = (SetAppCompatDataFunc)GetProcAddress(hDDraw, “SetAppCompatData”);
SetAppCompatData(12, 0);

Function SetAppCompatData, must be used before the function SetCooperativeLevel.

Hopefully Microsoft will release an update that will fix this problem.

I hope that Microsoft really solve the problem with an update. Or that the Snake, autor do Kega Fusion, bid logo version 3.65 correcting this problem also.

Kega Fusion running Out Run, do Mega Drive
Kega Fusion running Out Run, do Mega Drive
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Congratulations to, is a bit complicated to understand exactly what happens to happen this bug, however follow step by step what he described and the problem was solved…


Skooter have a similar problem with that on my Windows 8.1 however this happens with any version of epsxe urging it on my notebook… The problem is this:
Every time I change the screen to full screen only the sound plays and the screen goes black, only hear the audio… What could be? For works normally in Windows 7 and xp…


Pelo menos no 10 por enquanto esta tudo ok

Italo Oliveira

Friend, this part “Select fix DXPrimaryEmulation” (picture 3) it does not appear to select, what I do?!

Italo Oliveira

I did the second option and it worked (to copy the dll), so that not so operates FUSION, I tried to do with ZSNES and it did not work, sabe is this jeito the ZSNES tb amigo?!


Only adding to… Skooter tested this tip with GGPO and Supercade and both usually ran in full scren in case anyone has this same problem…However ePSXe unfortunately did not work the screen goes black in full screen… Esse Windows 8.1 although convenient and fast not being good with emulators…afs…

Mega Man

Video showing the solution to download the file
[vídeo removido do Youtube]

Bruno Henrique

Consegui 😀 VLW


It also serves as games mullet


Com o aparecimento do windows 10 diversos problemas aparecerão como: uma leve tremedeira em determinado contagem de frames no Fusion!!!! No Zsnes também tem essa leve tremedeira e, mesmo usando o modo de compatibilidade que nunca vi funcionar em sistema nenhumcontinua a mesma merd…!!!! A verdade é que esses emuladors em modo geral flui e executa de boa no Windows XP!!!! bons tempos do windows XP ou Linux!!!! earned

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