Change processor

[Karlos]

mdma wrote:

StormLord wrote:
you will need a cpu , some type of socket , and a regulator to drop the voltage from 5v to 3.3v that 060 needs. if you have an PPC card don't need a regulator just a change of a choke jumper. As for someone that hasn't had ENOUGHT experience with  iron and desoldering : AGAIN FORGET IT ! or take it to someone that knows!.
As for speed improvement ... its just.... umbelivable!!!!
about 4 times the speed of the 040@25..

:-o

That fast huh? Nice.

I have soldered before, but not for a while and for medical reasons I couldn't solder if i tried right now!

Might be worth looking into in the future, though if/when OS4 comes out, it switches the 68k off and uses the PPC to emulate all 68k code, so I imagine it would be a waste to upgrade the 040 to an 040. Or would it not?

Thanks for your advice.

Motorola rate the 68060's typical integer throughput as 1.7x that of the 040 at the same clockspeed for the same object code where no exceptions occur. So yes, a 50MHz 68060 would almost be 4x faster than a 25MHz 040.

Regarding OS4, the 680x0 processor makes no difference, it's basically shut down (so as not to steal bus cycles from the PPC). At that point only your PPC and memory speed matter.

You'll be quite surprised at how fast 680x0 stuff can run on that old 603 ;-)

It's worth upgrading to 060 if you want the best overall performance for OS3.x. Even the PPC is affected (I don't know what the exact cause is - slight differences in bus access maybe) but the PPC under WarpOS is faster with a 68060 than it is with 68040 (in every test I've thrown at it I see a completely systematic increase in PPC performance, even for stuff where no 680x0 calls are made by the PPC, so it has to be more than just context switch times).

I'd do it myself, but I'm a bit reluctant to screw the card up if I make a mistake :-)

[Karlos]

jlariv8957 wrote:
Hi,

Just one question : why PPC board on amiga make use of 680X0. I tought PPC had a 68K compatibility mode that could run old software. Macs wasn't using any 680x0 to execute 68K code!

Thanks.
 

The PPC has no 680x0 compatibility mode as it is in no way connected to the 680x0.

Macs just used a software emulation of the 680x0 for compatibility, just like OS4 and MOS do.

Of course one difference is that 680x0 emulation has improved enormously since macs first started doing it. My 603 runs rings around a 604 based mac I used (OS for running 68K code :-)

[Karlos]

@darkcoder

Fat binaries were a way of distributing executables in a single release that could run on both PPC and 68K systems during the time that Mac were introducing PPC.

StormC for WarpOS supports a similar notion (as well as PPC only, and mixed binaries - of which fat binaries are a special case).

As far as I recall, the last OS to run on 680x0 was OS8.x. Since there were PowerMacs running this already, I can only assume they had 680x0 emulation at that point.

MacOS 9 was PPC only (IIRC) - anything 68K was emulated at this point.

The early 68K emulation didn't set the world on fire. Early  powermacs ran 680x0 applications slower than the 040 macs they were replacing. That said, they were more intent on porting 68K code to PPC rather than finding out how to maximise 68K emulation.

Luckily for us, we have 680x0 emulation for our PPC systems (A1, pegasos, classic) several years later, in which time the methods used to emulate the 680x0 have advanced considerably. Thanks to JIT, even the slowest PPCs used in amigas can run 68K software respectibly. On the rather more powerful G3 and G4 based systems, 68K apps fly. I've seen A1s and Pegs run rings around WinUAE on much faster x86 systems - of course this is partially due to the fact that the OS is running native, whereas the x86 is having to emulate the lot.

[Karlos]

MskoDestny wrote:

Karlos wrote:
I've seen A1s and Pegs run rings around WinUAE on much faster x86 systems - of course this is partially due to the fact that the OS is running native, whereas the x86 is having to emulate the lot.

It also helps that OS4 and MOS make no attempts at emulating the rest of the hardware (which is probably particularly slow in UAE since it's designed to be able to handle software that requires fairly accurate cycle timings).

Also true, but to be honest I was talking about OS/RTG friendly apps that by and large don't use the original amiga hardware. As you know, WinUAE is extremely fast in this area but OS4 and MOS still have the advantage that the OS (and also many often used third party libraries etc) itself is native.

Regarding compatibility, a lot of custom hardware utilising stuff still works fine in OS4, provided you run it on an classic PPC machine.