68030 not running at 25Mhz

[psxphill]

Ok so the crystal is 25Mhz and the CPU is 25Mhz but sysinfo is reporting 13.4Mhz?
http://amiga.resource.cx/exp/professional530plus

sysinfo just guesses based on the performance of running some code, it has no idea what speed it's really run at. A lot of the time it reports incorrect speeds.
 
I'd check that the jumper settings are correct for the ram that is installed, look at the pdf online if you don't have a manual. Then poke around on disk as there is some software on there that you might need to use (the adf is online too).

[psxphill]

Will assume that it's halving the speed :-/

It is possible that the card halves the clock for the CPU but passes the full clock speed to the FPU. If you had a frequency counter you could check that.
 
The only thing I'd wonder is why it had a crystal that was too slow fitted in the first place. It is possible that the halving was jumper selectable, but unfortunately I don't speak german & so the pdf is no help.

[psxphill]

the manual from amiga.resource tells it is 68030 @ 14.3 MHz.

Yeah, it does say that. Putting in a faster clock might cause a problem for the ram. There must be a reason for them using such a slow clock speed.