Easy 68010 question...

[ChaosLord]

Looking for budget upgrades for my A500.  Those 68010's from China & Hong Kong that show up on ebay all the time... $5 bucks for a 5% speed increase, seems worth it to me, right?

Certain programs will run a lot more than 5% faster.  Certain special programs that make good use of loop mode will run 50% to 100% faster.

There was a famous old cracktro that was massively faster on 68010 than 68000.  Around double the framerate.

But remember that any old illegally coded games that use MOVE SR, instruction will crash on 68010.  (Maybe this is not a problem with WHDLoad, dunno).

[ChaosLord]

Actually all programs will run faster on 68010 than 68000.  The question is only "Will he notice that it went faster?".  Many times the answer will be no.  But sometimes the answer will be yes.

Its only $5.00 so its really no big deal at all to get 5 of them and go round upgrading all the A500s and A2000s in sight.


If he wanted to spend money he could get one of those vxl 030 cards (or similar) then he would have a 25Mhz 68030 with 16MB fastram.  It would be a lot faster than a silly 68010 and he would have the fastram to run a lot more software and games.  But I assume it would cost $100.00 for something like that.  He clearly does not love his miggy enough to spend $100.00 on her.  So for him the 68010 seems like a nice choice.

68010 has LOOP MODE.  This a 6-byte L1 instruction cache that ONLY works with a few instructions.  Yes they are the most common instructions so u do get value with LOOP MODE.

68030 has a LOOP MODE that works with everything.  And instead of working on only tiny 6-byte loops its works on all loops of 256 bytes or smaller.  So its a big upgrade from 68010.

68030 also has a 256 byte L1 DataCache which is a giant improvement over silly 68010.

68030 also has a Barrel-shifter so all shifts are massively faster.

68030 also performs multiplications and divisions massively faster than 68010.

68030 also performs all instructions at double speed of 68010.  68010 takes 4 cycles to perform simple instructions.  Those same exact instructions complete in only 2 cycles on 68030.  So a 7Mhz 68030 is always 2x as fast as a 7Mhz 68010.

The slowest 68030 you can buy is 25Mhz so you get another 3x speedboost for a total of 600% speed improvement over 68010.

[ChaosLord]

($100 for a 68030?  Dreaming!)

There are thousands of them out there.  Its just that they are laying in ppl's closets and ppl don't realize there are ppl like you that want to buy them.  If u could get lucky u could get one for free from someone who is going to throw it in the trash.

[ChaosLord]

@ChaosLord, What about the differences between 68010 and 68020 ?

68020 is exactly the same as 68030 with its datacache chopped off.

Without any datacache the speed of the processor gets crippled.

Its better to get a proper 68030.

Only reason to get an 020 is if it was free, or $5.00

[ChaosLord]

Of course, but not that much.

move.l (A0),D0 ; Speed zooms on 030 but 020 has no datacache so it has to sit around all day waiting for the RAM to cough up the data.

Those sorts of instructions happen all the time.

A 68020 based accelerator is perfectly fine, because you'll still see a great performance enhancement, simply because the instructions run faster from the instruction cache, and the higher clock speed.

The 68020 could be a nice and cheap alternative to the 68030.

A 68020 is a 68030 that is missing its tiny 256 byte datacache.  So there is no logical reason for it to be cheaper.  It costs the same amount of money to make an 020 as an 030 for decades.

But if someone wants to sell him an old used cheap one for $5.00 with onboard ram then sure its a good deal then.   I would even go as high as $7.00 or $8.00 possibly.

[ChaosLord]

For 3D gaming the 030 is better than 020.  For example the framerate in Stunt Car Racer is better.  Amiga has hundreds of 3D games that benefit from every ounce of faster CPU power.

256 bytes datacache is tiny, puny and pathetic but its still infinity times better than 0 bytes datacache on 000, 010, 020.

Of course the copyback datacache on 040 and 060 is massively better than the primitive write-thru cache on 030 but the OP would have to spend actual $$$ to get one of those.

[ChaosLord]

The 030 isn't the same as the 020, though they are, from a user mode, more or less equivalent. Along with the datacache, the full 68030 also has an MMU on the die, which no 68020 has.

Good point.  I was thinking from a "writing code perspective".

The MMU is good for debugging, filing bug reports and running emulators like those awesome Mac emulators.

Its a shame that Motorola went to all that trouble to make us an MMU and then so many ppl refuse to buy it / use it.

[ChaosLord]

If Amiga had made use of an MMU

Amiga does make use of MMU.

 then we could have somewhat less risk of bad things happening when running software.

We have that when you run MuGardianAngel.

[ChaosLord]

All software benefits from datacache.