Greetings @guest.r!
I’ve been having an issue with Shadow of The Beast for TurboGrafx-CD.
During the attract mode several full screen still images are cycled while some awesome CD background music is played, however during the transitions between stills the music pauses briefly and it totally messes up the timing and immersion of this simple but enjoyable part of this game.
This does not occur on real hardware.
I’ve tested it with redump images both CHD as well as uncompressed. Turned CD Cache on and off. With the image on an SSD as well as mechanical hard disk drive, it still occurs no matter what.
During my troubleshooting, I uncovered some interesting information with regards to performance and behaviour of different CRT Shaders including our beloved HSM Mega Bezel Reflection Shader.
Results of testing:
I disabled Video Shaders and it went away.
I use HSM Mega Bezel Reflection Shader but I didn’t suspect this as a contributor due to the fact that my GPU usage maxes out at 84%, while my CPU usage tops out at 7% during this intro sequence. I also have Run Ahead and Frame Delay enabled so I’m going to disable those or reset them to default and see what happens.
Disabling Run Ahead with the Shader running didn’t make a difference. Neither did Disabling Run Ahead plus resetting Frame Delay to 0 and turning off Automatic Frame Delay.
Going to try the Performance Shader Presets now.
With the Performance Preset in use, my maximum GPU usage drops to 76% (but it’s mostly tops out at 69%) while my CPU usage tops out at 4%
This is with Run Ahead and Frame Delay still disabled.
When I switched to HSM Mega Bezel Reflection Shader’s Potato base preset the issue is about 80% gone. There are still some signs of dropouts but they’re a lot shorter.
Max GPU usage is at 31% while CPU usage tops out at 5% (but it’s mostly at 1 to 2%)
After a while of looping its not as noticeable but I can still see the Frametime spikes and FPS drops and hear the slight pauses in the music during the attract mode scene transitions occasionally.
Tried Newpixie-CRT, no issues with dropouts whatsoever, smooth Frametime and framerate graph with max GPU usage at 17% and CPU usage topping out at 3%.
When I load CRT-GUEST-ADVANCE it’s probably a little better than when I tried the HSM Potato Preset. GPU usage maxing out at 27% and CPU at 2%.
CRT Royale-Composite seemed to have slightly less dropouts than CRT-GUEST-ADVANCE despite having similar GPU and CPU usage.
Lastly CRT-Geom Deluxe had a more consistent GPU usage figure of 40% with my GPU ClockSpeed remaining at a more or less constant 2000MHz and CPU usage at 2% Max and the issue was basically non-existent.
Even after playing around with some of the Shader Parameters in CRT-Geom Deluxe which caused my GPU Usage to increase to 59% Max and my CPU Usage to top out at 3%, the intro music in Shadow Of The Beast still played on without skipping a beat!
I tried setting my GPU to Prefer Maximum Performance but the problem was still there when I repeated using my HSM Mega Bezel Reflection Shader presets.
All of these tests were run with CD Cache Enabled in Beetle PCE Fast’s Core Options.
All of the test I ran besides the Potato and my initial tests using my presets were performed with the stock versions of the Shaders/Presets available in the Shaders_Slang folder unless otherwise indicated. I’ll test with another system. I’m running a mere Gefore GTX 1070.
After updating my Realtek Audio Drivers from the Gigabyte Website (since for the longest while Realtek seems to no longer be supplying their latest drivers to end users), I remembered that I don’t use Realtek Audio at all. I use nVIDIA HDMI Audio. My main PC is a HT/Gaming/Living Room PC hooked up to a receiver and a 4K TV via HDMI.
My nVIDIA HDMI Audio Drivers are as new as can be. They were probably updated about a day or 2 ago.
Just ran some tests on some more Shaders/Presets. RTSS Frame Limiter was off for these:
Guest Dr. Venom 2 37%, 2% - Audio Dropouts noticeable
Guest Dr. Venom 25%, 2% very slight, hardly noticeable but it’s there. After a few cycles, the FPS drop is about 2fps - the spikes are there but it’s even less noticeable.
Guest Dr. Venom Fast 18% 3%. Spikes can be seen, audio dropouts noticeable.
crt-guest-sm.slangp 23%, 3% No audio hitches for the most part but you can see the tiny blips on the RTSS Frametime and FPS Graphs plus you can hear an occasional audio dip but it’s extremely slight. Flawless after some cycles.
The percentages are max GPU and CPU usage figures during the test sequence respectively.
The problem seems to occur exactly between the image transitions. Something seems to be stalling at the exact moment the screen fades completely to black. Depending on the preset used its enough to desync the audio.
By the way, I switched on CRT-Geom-Deluxe in between and it was flawless, not even a spike. Of course that doesn’t do half as much as what CRT Guest Advanced can do but the GPU usage is around double that of Guest Shaders, yet the audio doesn’t budge.
Here’s a video clip showing the issue:
Nevertheless, the dl link is updated now.
