68030 not running at 25Mhz

[AmmoJammo]

It wont result in the cpu running at 13.4mhz though :/ what does it do it "fall back" mode?

[ChaosLord]

According to TBBOAH ram on this card is not autoconfigured. No (active) 32 bit ram will result in terrible performance.

What you are saying is 100% true.

BUT....

None of this makes any sense at all.

His 32-bit ram must be active because he told us his instruction cache was enabled and using burst mode. :idea:

But then why did he have his Datacache Burst Mode disabled? :crazy:

None of this makes any sense.

Either both instruction cache and datacache should be in burst mode or neither one should be. :rtfm:

I hereby award this accelerator card the "Screwiest Accelerator Ever Award" :insane:

[mongo]

What you are saying is 100% true.

BUT....

None of this makes any sense at all.

His 32-bit ram must be active because he told us his instruction cache was enabled and using burst mode. :idea:

You can turn burst mode on even if you don't have any fast ram.

The 68030 on this card always runs at 28.5 Mhz. The crystal is for the FPU only.

[Lurch]

RAM is configured, I have used the addmem command and also used the install disk which puts a script in wbstartup :-)


A thought I've had is it's not seeing the crystal on the card.

You can turn burst mode on even if you don't have any fast ram.

The 68030 on this card always runs at 28.5 Mhz. The crystal is for the FPU only.

Would be happy with 28.5Mhz but its 13.4Mhz :-) Whats the secret in getting the CPU to run at full speed?

[AmmoJammo]

The 68030 on this card always runs at 28.5 Mhz. The crystal is for the FPU only.

is it set by the original crystal on the motherboard?

[bloodline]

Ok so the crystal is 25Mhz and the CPU is 25Mhz but sysinfo is reporting 13.4Mhz?

My card -

http://amiga.resource.cx/exp/professional530plus

Sysinfo has no idea what clock speed your CPU is running at. It just makes a guess based on some timed loops which run at different speed on different CPUs... It probably isn't accurate on anything other than a 68000...

[AmmoJammo]

Sysinfo has no idea what clock speed your CPU is running at. It just makes a guess based on some timed loops which run at different speed on different CPUs... It probably isn't accurate on anything other than a 68000...

AIBB/sysspeed all state 13 or 14.5Mhz so something weird going on here.

25Mhz Crystal
25Mhz 68030
25Mhz FPU

Maybe something software wise :-/ 68030.library?

even if it is reporting the speed wrong, it's still benchmarking as a 13Mhz CPU...

[Lurch]

Benchmarks as a 13.4Mhz CPU not at 25Mhz or higher. Sysinfo/Sysspeed/AIBB all the same.

Going by Mongo the Crystal is for the FPU and the CPU should be running at 28.5 Mhz.

So tonight when I get home will see what happens when I remove the Crystal and FPU from the board :-)

is it set by the original crystal on the motherboard?

If that's the case then 13.4Mhz is about right 2 x 7Mhz?

[ChaosLord]

Benchmarks as a 13.4Mhz CPU not at 25Mhz or higher. Sysinfo/Sysspeed/AIBB all the same.

Those programs measure your cpu speed by executing instructions from the instruction cache.

Maybe your instruction cache is getting errors by trying to burst from a memory area that does not support bursting.

Try disabling the burst mode on your instruction cache to see if that makes any difference.  Make sure not to disable the whole instruction cache.  Only the Burst Mode.

[ChaosLord]

Sysinfo has no idea what clock speed your CPU is running at. It just makes a guess based on some timed loops which run at different speed on different CPUs... It probably isn't accurate on anything other than a 68000...

If sysinfo is properly coded then it should be extremely accurate on all CPUs.

I am not saying it is properly coded.

I am just saying that if it was then using the "timed loops" method is very reliable.  It would only be guaranteed unreliable on new chips released after the program was written.

[ChaosLord]

If your card is getting its Mhz from the motherboard then you could plug in a Commodore Genlock and dial up the knob and see if it increases the speed of your CPU.  If your cpu speed goes up then its getting its speed from the Amiga.

Its a trick someone told me many many years ago.

[Lurch]

Will give it a shot Choaslord, only thing I can't try is using a Commodore Genlock. Not a piece of kit I own :-/

More to come :-)