3D - F030 vs Amiga 1200

[Frank B]

I'm aware a good programmer can get some additional speed by taking use of the DSP, but the real life speed increase compared to just using the 030 instead is not that extreme that some Atari ST fanatics claims it is. And when the DSP are being used, it has some down sides, like slowing the RAM bus ore something else down, so other stuff that might are running at the same time will suffer. That's my understanding after reading what I can here and there. I have not had an F030 to experience with myself, I've just have a normal Atari ST.

The DSP does not slow down the CPU. It has its own separate RAM. There is another advantage of the ST/Falcon architecture. The data cache can work with ST (Chip) RAM. On the Amiga chip RAM access is only cached via the instruction cache. The ST has a clearly defined interface to bitblit which takes care of flushing the data cache on every graphics operation. Remember that the Falcon has a 16 mhz 16 bit bus to ST ram. The 1200 has a 7 mhz 32 bit chip RAM bus for the CPU. That's why fast ram gives you such an increase in speed on the 1200. As an aside the 030 on the Falcon has an MMU too.
The Falcon blitter can also gourad shade via x increment registers and true colour mode which the Amiga blitter lacks. Details here... Enjoy http://s390174849.online.de/ray.tscc.de/gouraud.htm

[troed]

I'm aware a good programmer can get some additional speed by taking use of the DSP, but the real life speed increase compared to just using the 030 instead is not that extreme that some Atari ST fanatics claims it is.

The person you replied to, "dml", has created both a version of Doom (with extensions) for stock unmodified Falcon, as well as being well underway with a Quake II compatible rendering engine (again, stock unmodified Falcon). His threads detailing that work are some of the most interesting threads I've read when it comes to optimization using both the 68030 and DSP 56001 in tandem. The real life speed increase to just using the 030 is indeed quite extreme when it comes to the 3D math.

(I'm myself a demo coder from the good old days. The difference between faking everything for a demo effect and actually doing the math needed for a game is huge)

It would improve the discussion in this thread if everyone reads up on those threads since they're very much on topic.

Quake 2 thread: http://www.atari-forum.com/viewtopic.php?f=68&t=26775

Badmood (Doom) video:

Quake 2 engine (WiP) video (texturing, I think there are later ones without texturing but with faster 3d calculations):

/Troed

[CiH]

I'm aware a good programmer can get some additional speed by taking use of the DSP, but the real life speed increase compared to just using the 030 instead is not that extreme that some Atari ST fanatics claims it is - SNIP!

Troed, I could not have put it any better

Flash - I assume that you've lurked around other parts of this board and not just spent time on this thread?

[Zamuel_a]

When it comes to 3D, wouldn't the most important benefit here be that the Falcon has a real chunky graphic mode so that you can plot pixels directly. This must be a lot faster than using some c2p technic I guess you always must do on an Amiga? (unless it's flat shaded polygons)

I remember I read in an old techincal comparison between the Falcon and the A1200 that they thought the Falcon 16bit RGB mode wasn't as good as the HAM8 mode on the Amiga. This might be true, but you can only use HAM mode to draw static images and if that is all you want to do, I guess you can use some clever tricks to display a lot more than 64k color images on an Falcon to

[Anima]

When it comes to 3D, wouldn't the most important benefit here be that the Falcon has a real chunky graphic mode so that you can plot pixels directly. This must be a lot faster than using some c2p technic I guess you always must do on an Amiga? (unless it's flat shaded polygons)

Even flat shaded polygons are not faster on the Amiga 1200. The Blitter is not only the same as the one in the Amiga 500/600 but it also runs at the same speed. So there's no real advantage using it at all. The sole reason to include it in the Amiga 1200 was to maintain the compatibility.

The Atari Falcon Blitter is running at 16 MHz which makes it (almost) twice as fast as the Atari STE Blitter. The true advantage is that programs can utilise the instruction cache while the Blitter is busy drawing pixels. One example is that the CPU calculates new Blitter setup parameters for each line to draw polygons or circles at maximum speed. This is one of the reasons why the Blitter is underrated (see the examples posted by Frank for other use cases).

Here's a very short video demonstrating the circle drawing approach (jump to the 2:50 mark):

Edit: [For those without Flash please use this link.]

[Zamuel_a]

The Atari Falcon Blitter is running at 16 MHz which makes it (almost) twice as fast as the Atari STE Blitter. The true advantage is that programs can utilise the instruction cache while the Blitter is busy drawing pixels. One example is that the CPU calculates new Blitter setup parameters for each line to draw polygons or circles at maximum speed. This is one of the reasons why the Blitter is underrated (see the examples posted by Frank for other use cases).

But its only one instruction you can execute while the blitter works so I guess it must be a mul or div or it won't make much difference.

I tried to draw polygons with the blitter on ST a while back and it was about 30% faster than a normal routine so it had been nice to do something useful of it sometime.

[Anima]

But its only one instruction you can execute while the blitter works so I guess it must be a mul or div or it won't make much difference.

I tried to draw polygons with the blitter on ST a while back and it was about 30% faster than a normal routine so it had been nice to do something useful of it sometime.

You're right, the STE can only execute one completely prefetched instruction while the Blitter is using the bus. On the Falcon it's a different story: as long as you avoid accessing the memory (except for cached data) and the code keeps within the instruction cache it runs in parallel with the Blitter. So for example drawing Bresenham circles can be done by using registers only. On a side note the routine is able to draw two 8 bitplane lines with one Blitter call.

[Zamuel_a]

You're right, the STE can only execute one completely prefetched instruction while the Blitter is using the bus. On the Falcon it's a different story: as long as you avoid accessing the memory (except for cached data) and the code keeps within the instruction cache it runs in parallel with the Blitter. So for example drawing Bresenham circles can be done by using registers only. On a side note the routine is able to draw two 8 bitplane lines with one Blitter call.

I didn't know that you could do that on the Falcon. That could ofcourse speed up things alot in some situations.

[Flash951]

The blitter in the Amiga is used for the real time dragging of separate screens in the OS. For example having 320x200 128 colors and 640x512 16 colors on screen simultaneously. For that unique feature of the Amiga OS, it works perfectly on both OCS, ECS and AGA screens. Even if the blitter is the same for all Amiga's, it has 32 bit access to chip ram in the "plain" 32 bit Amiga's, the A3000(t), A1200, A4000(t) and CD32.

The Quake and Doom demos was impressive for a 030 computer.

Doom on an Amiga 1200/030 AGA, clocked a little higher than the 16MHz F30 though.
https://www.youtube.com/watch?v=tUbEwkWr4E4

[Zamuel_a]

Doom on an Amiga 1200/030 AGA, clocked a little higher than the 16MHz F30 though.

I wouldn't say 50MHz is just a little higher. But it still looks slow. I have an 1200 with a 68040 40Mhz accelerator and on that one DOOM run at a decent speed.

[jfl]

Doom on an Amiga 1200/030 AGA, clocked a little higher than the 16MHz F30 though.

A little higher? Yes, I would have to agree that 50MHz is "a little higher" than 16...

[calimero]

The blitter in the Amiga is used for the real time dragging of separate screens in the OS.

I am pretty sure that blitter has nothing with multiple resolution at once on screen and scrolling (dragging) screens up and down (but someone with Amiga coding experience could explain this better).

Doom on an Amiga 1200/030 AGA, clocked a little higher than the 16MHz F30 though.
https://www.youtube.com/watch?v=tUbEwkWr4E4

are you serious? 50MHz is not little higher but 2,5 times faster (plus it use FastRAM on that accel. board)!

[Frank B]

The copper is responsible for screen dragging on the Amiga not he blitter. The Amiga blitter is 16 bit but is slightly faster than the Ecs one due to faster bit plane fetches via fmode. I'd recommend reading the hardware reference manual for the Amiga. It will clear a lot of this basic stuff up for you.

[CiH]

Doom on an Amiga 1200/030 AGA, clocked a little higher than the 16MHz F30 though.

Nice hardware, reminiscent of my Centurbo 2 spec, which also has the DSP clocked to 60 MHz as well.

[EvilFranky]

Ah right, so we are still trying to push the conversation down the modified Amiga vs stock Falcon route...

[Flash951]

I totally agree, the copper is of course used for the screen dragging.

[Flash951]

Ah right, so we are still trying to push the conversation down the modified Amiga vs stock Falcon route...

Don't worry, this conversation is still about the low end Amiga model vs the hi end Atari model.

[calimero]

Ah right, so we are still trying to push the conversation down the modified Amiga vs stock Falcon route...

Don't worry, this conversation is still about the low end Amiga model vs the hi end Atari model.

and bad mathematica: "Doom on an Amiga 1200/030 AGA, clocked a little higher than the 16MHz F30 though."

[Zamuel_a]

Don't worry, this conversation is still about the low end Amiga model vs the hi end Atari model.

No it's about Amiga 1200 and Atari Falcon, which are equal models. But of course, if you want to call it a low end Amiga, I'm fine with that

[Flash951]

Amiga 1200 was the low end entry model, replacing Amiga 600 and Amiga 500+. The high end model was the Amiga 4000/040 replacing the Amiga 3000. A year later the "low cost" Amiga 4000EC/030 was released and at last the 4000 tower with either 040 or 060.

[FedePede04]

the Falcon f030 was the entry level Atari Falcon build to replace the 520-1040 ST/STE.
so what is your point,
this hole thread is to compare a stock falcon fc30 with a stock amiga 1200, not with some fancy hardware add on.

and this is obvious for me that the falcon wins hands down, and you also know it. that is probably the reason why you have become more and more like a TROLL.

and if you like to compare different hardware not related to this thread, then my setup of that time probably win over both. Intel 486 dx 33mhz. 32bit 33mhz opti local bus. sb pro II. but what does that have to do with it, I do not know

[ctirad]

BTW, what makes the A4000 so "highend" except its astronomical price? A4000 has exactly the same chipset as the A1200. Exactly the same video modes, exactly the same audio modes, exactly the same 2MB Chip ram of exactly the same speed, exactly the same IDE, exactly the same DD (!!!) floppy controller, same LPT, same COM. The only difference is more powerfull CPU on th edaughterboard with a fastram and a Zorro slots. The speed of the original FastRAM controller is nothing spectacular for both 030 and EC030 version. The A1200 with a 040 accelerator on the same clock outperforms A4000 easily because of faster controller and RAMs.

[Flash951]

Because the fact that you choose the entry level Amiga model to be compared to the flag ship Atari model says it all. And also want to compare only the 3D speed.

BTW, what makes the A4000 so "highend" except its astronomical price? A4000 has exactly the same chipset as the A1200. Exactly the same video modes, exactly the same audio modes, exactly the same 2MB Chip ram of exactly the same speed, exactly the same IDE, exactly the same DD (!!!) floppy controller, same LPT, same COM. The only difference is more powerfull CPU on th edaughterboard with a fastram and a Zorro slots. The speed of the original FastRAM controller is nothing spectacular for both 030 and EC030 version. The A1200 with a 040 accelerator on the same clock outperforms A4000 easily because of faster controller and RAMs.

Answer: The Amiga 4000 has great expandability (32 bit slots -Zorro III, ISA, video slot. The Amiga 4000T has both built in Fast SCSI 2 controller and HD floppy (HD=the ones from Commodore. 1.8 MB), (I had one), the 4000 also had HD floppy. The Amiga 4000T/060 came with a faster Fast RAM bus on the CPU card that could fit 128 MB. The A4000T has unlike the A1200 a buffered IDE port. The A4000 had 4 more custom chips.

[christos]

Actually the A4000 bus is slower than the A1200 bus. But fire away, I am pretty interested to see what a 030 A4000 can do.

[Flash951]

Actually the A4000 bus is slower than the A1200 bus. But fire away, I am pretty interested to see what a 030 A4000 can do.

Why are you hang up with the A4000EC30, this is the economy model which came later. The A4000 that came in -92 when F030 also came, is 040 as you now, there is no -92 A4000 with 030. All A4000T machines came with either 040 or 060, can't you read? There is no 4000T 030. The 060 one has much faster RAM bus as it is directly on the CPU card where 128 MB can fit.

In both A4000 and A4000T, the on mainboard RAM can be software switch to 60ns instead of 80ns.