Pues para mi sorpresa me he encontrado con esto por la red, un hack del juego que solo permite jugarlo con el cartucho de ram extra, para asi hacer el juego mas "suave", os copio pego la info al respecto:
## Sega Saturn Akumajou Dracula X - YZB Optimized Version(4MB RAM Cart required)
### General
* This version is based on the Japanese release. If you want to run it on a different region Saturn, use a Saturn Region Patcher first.
* This optimization hacks modified file accessing mechanism only.
No additional change in sound, GFX, or movement control.
* 4MB(32Mbit) RAM Extension Cartridge is required for this release.
(Emulator users need to make proper cartridge settings in option.)
A warning message would be displayed if there's no 4MB RAM cart inserted.
## Sega Saturn Akumajou Dracula X - YZB Optimized Version(4MB RAM Cart required)
### Updates
#### 2020.05.14 22:30
* Fixed graphic glitch on RAM Cart warning screen.
* Fixed random crash on checking initialized RAM cart.
* Improved algorithm on checking initialized RAM cart.
* Improved formatting of this document to adopt MarkDown syntax.
#### 2020.05.09 22:00
* Compressed game assets files, to optimize the read performance.
* Significantly speed up the Map UI accessing.
* Significantly speed up the in-game menu accessing for Alucard.
* Added in-game short-cut key for directly accessing Map UI:
1. Richter Belmont and Maria Renard: Press L during gameplay for Map UI.
Press L or B to return the game.
2. Alucard: Press R while holding B for Map UI. As L button has pre-defined
in-game function for Alucard(item on his 3rd hand-slot).
3. For Alucard, press L in Map UI will directly open the in-game menu. Press
B in Map UI to return the game.
* Character's animation playback is optimized, avoid repeatedly run the LZSS
decompression code. Frames now directly memory copy from Extended RAM.
* Other misc optimized features included:
1. Press start key for skipping the intro scene.(Originally require at least
one clearance of the game)
2. Optimized file LBA on disc image.
3. Filled 100mb dummy data to make game data away from the inner region.
4. Filled 100mb dummy data at the tail to avoid week Lead-Out interfere the
sector seeking near the tail part.(Occasionally happen on some CD burner)
### Supplementary info on data loading:
* For the first time the waving "Now Loading" displayed on the screen. Around
3MB of data would be loaded. Usually need 15-20 seconds, depending on your cd
drive. This is a one-time-only job during one power cycle. Please avoid turning
the console off during this process.
* During the gameplay, except for general level switch and boss room event, disc
file data will not be accessed as they have been cached in RAM cart. (But audio
and video data files will still be accessed on-demand)
* Level switching and boss room loading would be slightly faster than original.