68030 not running at 25Mhz

[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.

[Seiya]

maybe the problem is sysinfo that not can identify che board.
you can try other benchmark, like aibb and compare your 68030@25 with A3000 with 030@25 by default.

[zipper]

Seems the CPU frequency is divided by 2 from the xtal - the manual  from amiga.resource tells it is 68030 @ 14.3 MHz. And from the pic in BBOAH seems there's another version of 33 MHz, with 66 MHz xtal.

[AmmoJammo]

I did say put the 40Mhz crystal in and see what happens... :p

that's pretty much the fastest crystal you're going to be able to use, unless you can clock the FPU at half the crystal speed too

[zipper]

The manual tells you can clock the FPU separate with another osc (upto 33 MHz, perhaps more) and it's auto-sensed - but can't see any place in the pics to put it in.

[AmmoJammo]

The manual tells you can clock the FPU separate with another osc (upto 33 MHz, perhaps more) and it's auto-sensed - but can't see any place in the pics to put it in.

nor could I? plus I couldn't read German :p

My Mega Midget Racer has spots for two crystals, you can then use jumpers to either clock the FPU at the same speed as the CPU, using a single crystal, or clock it at its own speed, using a separate crystal...

[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.

[Lurch]

The other fear I have reading the manual is it's stuck at 14Mhz no matter what LOL

I don't see how I can clock the FPU seperate from the CPU, but would be handy to do.

Hopefully have the crystal in the mail today/tomorrow (wishful thinking) and I can give it a go with that.

Would suck that I can only get 20Mhz out of it. Maybe I need to spend some cash on a ACA500 after all :-(

[Lurch]

nor could I? plus I couldn't read German :p

My Mega Midget Racer has spots for two crystals, you can then use jumpers to either clock the FPU at the same speed as the CPU, using a single crystal, or clock it at its own speed, using a separate crystal...

My VXL-32 has this option, downside to that card is I don't have the RAM module. So pointless using it as it's not much faster if at all than my 68010.

Unless someone wants to swap/trade? :-)

[AmmoJammo]

Realistically, the FPU will take upto 40Mhz, but as someone mentioned, the memory might not, 30Mhz? maybe 33Mhz or even 36Mhz are all possible, but you'll still only be running the CPU at half this speed.

[Lurch]

My original aim was to play space quest/kings quest enhanced at a decent speed. Runs okay at 7Mhz but slow and laggy.

Then had the idea of trying Doom, which should be sorta playable at 40Mhz. So unsure about anything slower.

If I can get 33Mhz that would be good, although you mention that 40Mhz would be pushing it for the FPU to cope?

As it appears I cant seperate the two if I put a 66Mhz crystal in would the FPU fry itself? I could always remove it :-)

[AmmoJammo]

The issue may be that the memory won't run at the higher speeds anyway...

try with the 40Mhz crystal, see what happens, take it from there

[Lurch]

Must have more power :-)

[AmmoJammo]

FPU should be ok at up to 50Mhz.. that's whats in mine... so, try the 40Mhz, if that works, step it up!

at least IF the 50Mhz crystal works, you'll have the CPU at 25Mhz

edit: which FPU do you have? 68882? or 68881?
if the FPU doesn't work at higher speed, you can probably remove it and use a 60Mhz crystal, the specs say you can run the 68882 at upto 60Mhz, so I assume the rest of the card will accept this, I assume everything else is running at half this speed anyway.

[Lurch]

It has a 68882, if that's the case I'll see if I can track down a 60Mhz crystal. An extra 10Mhz would be great.

Seems weird that it should halve the speed for the CPU and not that the FPU. Have checked the board a couple of times and I can't see where you can set the FPU to be seperate from the CPU :-/

Craziness TBH.

[AmmoJammo]

did you get it, did you get it, did you get it, did you get it?