A: The overall (subjective) feeling of the UAE and Fellow emulators (without JIT technology) is that a Pentium CPU running at 133 MHz compares well with an Amiga 500, providing enough usability for tasks such as word processing and programs such as Personal Paint, but no real time emulation of the Amiga custom chips. Additionally, the Picasso96 screen modes not only offer high end graphics features, but make the emulation run faster than with the original Amiga modes. It certainly makes an impressive and very useful Amiga notebook. The use of sound, custom chip logic and the type of frame refresh rates used in many games require more powerful machines and in extreme cases can push even a 750 MHz system to its limits. Other parts of the emulation, such as the file system, can easily be faster than an original Amiga when an Amiga partition on the emulation environment is mapped directly to the host file system. A Pentium Pro or Pentium II running at 200 MHz feels like an Amiga 3000/030, again with a very responsive file system, and even a faster windowing action when used with the Picasso96 drivers. To make an example of a CPU-intensive task, compiling Personal Paint with SAS/C in UAE emulation on a Pentium II/400 MHz system takes about as long as on an Amiga 4000/040. By comparison, the CPU of an Amiga 4000/060 is about 2-3 times faster than an Amiga 4000/040 (the 68060 is roughly twice as fast as a 68040 running at the same clock speed). Intel systems running at 300 MHz have been tested running some of the most demanding games in real time, without missing a single frame. At 1 GHz, it can be claimed that all functions of the original Amiga 1000 computer can be emulated in real time under the most challenging conditions.
Newer versions of the emulation software include a "just-in-time" (JIT) compiler, developed by Bernd Meyer, which, when enabled, can make the emulation of the CPU on average at least 10 times faster than without JIT. Benchmarks conducted with Personal Paint (color reduction and image processing tasks) resulted in speeds more than 30 times faster than without JIT. This means that tasks which used to take minutes on older versions of the emulation software can take seconds with JIT. This makes even an old and inexpensive 200 MHz PC faster at running Amiga software than a 68060-based Amiga (benchmark: SAS/C compiling Personal Paint).
Cloanto publicly benchmarked the Amiga emulation software included with Amiga Forever 5.0, comparing it with that of Amiga Forever 4.0 and with third-party packages which were running on systems kindly made available by attendees, and allowing independent reviewers to study the tests and measure the times (even on their own computers) at the following events: