68030 not running at 25Mhz

[AmmoJammo]

is the crystal thats currently in there around the right way? :p

[Lurch]

LOL yep, even tried another crystal. Who knows haha :-)

[AmmoJammo]

same speed crystal I assume?

don't have any other speeds lying around do you?

[Lurch]

Just have the two crystals, both 25Mhz though. Waiting for a 40Mhz that I bought, will give that one a go.

[ChaosLord]

Is it just 1 crystal that controls both CPU and FPU?

Or are there 2 different crystals?

Maybe the FPU crystal speed is somehow interfering with the CPU crystal speed?

I don't really know about such things.  I am just throwing out an idea.



Are your CPU caches on?  If some evil program somewhere is disabling them for some reason this could explain slowness.

[AmiDude]

I guess it divide the clock with 2. So the crystal may have been swapped. What is the speed on the cpu?
(Text on the top of the cpu)

If you have a 16mhz 030, you need a 30mhz crystal. If a 33mhz 030 use a 66mhz and so on.

Nonsense! That counts only for 68040 CPU's.

@ Lurch

Don't put in a 40Mhz crystal! You'll probably burn the 25Mhz CPU. The reason why sysinfo reports only about 13Mhz is that the Cache jumper on the turbocard is probably disabled.
Have a look at the jumper info on http://amiga.resource.cx/exp/professional530plus

Edit:
And do you have any FastRAM memory on the board? If not, then that could be also a reason for the turbocard to slow down. FastRAM memory is essential for speeding up the CPU!

[AmiDude]

So will need to source a 80Mhz crystal ? :-(

Noooooooo! You will vaporize the cpu! :eek:

[AmmoJammo]

Noooooooo! You will vaporize the cpu! :eek:

Attempting to overclock a processor beyond its limits won't simply result in it instantly failing...

Chances are it won't do anything with a 40mhz crystal.
Even if it does successfully boot, it won't just magically fail before you have a chance to run sysinfo and see what speed its running at.

[AmiDude]

Attempting to overclock a processor beyond its limits won't simply result in it instantly failing...

Chances are it won't do anything with a 40mhz crystal.
Even if it does successfully boot, it won't just magically fail before you have a chance to run sysinfo and see what speed its running at.

Yeah, but he's talking about using a 80Mhz crystal on a 25Mhz CPU.
It's very likely that the Cpu won't survive that. I once stupidly used a 40Mhz on a 25mhz CPU and then the thing was dead.

[ChaosLord]

@Lurch

Please type

Code: [Select]


CPU

into a shell window and paste us the results.

p.s. I would not try to use an 80Mhz crystal with a 25Mhz cpu.  That sounds very dangerous.  If you are going to do that then please let your CPU say goodbye to her friends and family first.

[paul1981]

Sysinfo mostly does educated guesses about the frequency - you need something more reliable.

Use this. Never fails me:
http://aminet.net/package/util/moni/WhichAmiga

[ElPolloDiabl]

Could a - resistor - that works as a divider on the card failed?
I doubt it needs a 50mhz oscillator to work at 25mhz.
14mhz is twice the 7mhz 68000 speed. Could the card have the wrong settings somehow?

[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).

[BuzzBrain]

Nonsense! That counts only for 68040 CPU's.

My bad!!
There is a picture of a proffessional 030 from Harmac Computertechnik on "the big book of amiga hardware" who have a 66mhz crystal. And the cpus (cpu/fpu) is 33mhz

Another picture shows a 16mhz card with a 030 20mhz cpu and a 33mhz fpu..with a 40mhz crystal.

Asume those boards is OC.

Sorry for the missunderstanding.

[Lurch]

AIBB also confirms half the speed, although it shows the FPU at 25Mhz

There is 4MB RAM on the card.

System: 68030 68882 (INST: Cache Burst) (DATA: Cache NoBurst)

Will assume that it's halving the speed :-/ So when I finally get my 40Mhz crystal I'm assuming it'll be 20Mhz. If this is the case I'll need a 80Mhz Crystal to get the full 40Mhz CPU.

Strange card. Wont really know until I get the faster Crystal I guess.

I'd say the cache is on going by the cpu command result, also using setcpu states the same thing. There's only the one crystal on the card so don't see a separate one for the fpu.

[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.