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Old 12 November 2009, 17:09   #21
Anemos
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Truth is FPU not useful about of all games-programs..
But addend prestige on your accelerator..
some demos support 2 version with or without FPU.
Quote:
Two versions of the demo are provided, one which will work on all Amigas with a 68020 and above and one which is accelerated for use with a Floating Point Unit (FPU). The files are about 630 KB of size.
http://www.haage-partner.de/amiga/products/ds_sup_e.htm

.
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Old 12 November 2009, 17:13   #22
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Originally Posted by StingRay View Post
care to elaborate? Or even better, send corrections to the ADA team so they can fix any obvious errors? *shakes head*
Sorry, I should clarify. The minimum requirements on ADA should be taken with a pinch of salt. Accurate though it may be, as you can see from the NFO's it also usually says something like "Requires 68020 + FPU but don't bother try this on anything less than a 68060".

http://www.scene.org/file.php?file=/...a.lha&fileinfo
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Old 12 November 2009, 17:14   #23
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Some 1st person games benefit from an FPU too
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Old 12 November 2009, 17:19   #24
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Doom is/was all fixed point maths so I doubt it uses it. Quake is 060 only.
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Old 12 November 2009, 17:21   #25
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Quake runs on an 040
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Old 12 November 2009, 17:22   #26
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One of the amiga Dooms requires an FPU to run.
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Old 12 November 2009, 17:31   #27
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"And no, ADoom wouldn't be any faster if it used the FPU, because DOOM
doesn't do any floating-point arithmetic..."

http://aminet.net/package/game/shoot/ADoom-1.3

If any Amiga Doom uses FPU it is unlikely to be for the game engine.
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Old 12 November 2009, 17:36   #28
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I' aware of that with ADoom...i think it was Doomattack benefited from the FPU.

Besides if you type in "amiga FPU required" in Google there's lots of programs and a few games that either require OR benefit from the FPU.

Wether or not you are ever going to use them though is another matter.
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Old 12 November 2009, 18:10   #29
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DoomAttack doesn't appear to use the FPU. There is some mention of it in the 060 null modem driver but nothing more.

Quote:
Originally Posted by DoogUK View Post
if you type in "amiga FPU required" in Google there's lots of programs and a few games that either require OR benefit from the FPU.
Strange, I only get POV Ray & Quake

http://tinyurl.com/yaxy2nf
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Old 12 November 2009, 18:14   #30
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So the FPU can provide further processing power but nothing actually uses it that's worth noting?
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Old 12 November 2009, 18:15   #31
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I wouldn't say nothing, but very few. Too few to worry about getting one IMO.
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Old 12 November 2009, 19:24   #32
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I'm with Alex on this. It's easy to think that it's like in the movies where they just plug in more chips and boards and things automatically get better

It's not going to make your Workbench zippier, and it's only a tiny tiny fraction of the games and software for the Amiga which will benefit from it. Software has to be written specifically to make use of the FPU, and in many cases there's just nothing that motivates doing FP arithmetics because integers are sufficient and also faster.

There were some good renderers like Imagine, and a bunch of good demos that made use of or even required an FPU, and I think I got good use of the FPU I had for my B1230, but more than anything I bought it just because I felt it made my Amiga more complete.
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Old 12 November 2009, 20:33   #33
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Quote:
Originally Posted by plankton View Post
So this is what I understand and assume to be true:

- FPUs are not totally useless but underutilized except for demos and raytracing.
- Software that utilizes an FPU will do so even if it's running at a lower clock speed than the CPU and results will be better than no FPU.

Anything wrong there?
Anything built from c that uses floats or doubles benefits from an FPU. I ported some old float heavy fractal code on lattice and it was 22x faster when targeting the 68882. YMMV.
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Old 12 November 2009, 20:54   #34
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Quote:
Originally Posted by frank_b View Post
Anything built from c that uses floats or doubles benefits from an FPU.
Only if it is compiled with a C-compiler which supports FPU extensions or uses an external math library which in turn was made with support for FPUs.

Otherwise floats and doubles are just emulated using fixed point.

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Originally Posted by frank_b View Post
I ported some old float heavy fractal code on lattice and it was 22x faster when targeting the 68882
Possibly, but most software written in C for Amiga isn't compiled for FPU. The reason being compatibility.
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Old 12 November 2009, 21:15   #35
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How much heat does a FPU pump out when nothing is using it?

Doesn't the LHA compression program use a FPU is there is one available? I have a 1230/50 with 50 FPU and uncompressing files seems to run pretty fast.
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Old 12 November 2009, 22:31   #36
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Quote:
Originally Posted by Unknown_K View Post
How much heat does a FPU pump out when nothing is using it?
Probably the same amount as when something is thrashing it. I doubt they are like modern CPU's which have energy saving modes when they are not being used.

Quote:
Originally Posted by Unknown_K View Post
Doesn't the LHA compression program use a FPU is there is one available?
Which version? There appears to be nothing in the 1.50r 68000 or 020 versions. Not surprising as standard compression routines are usually integer based.
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Old 12 November 2009, 22:47   #37
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I've had a bliz 1230IV with FPU since about 96 and in that time I've used it occasionally with ray tracers, fractal generators, and nothing else.
Bit of a waste of money, but I had a student loan so there you go.
If my FPU had stopped working in 98 I probably wouldn't have noticed since.

Now an MMU on the other hand... that is GOLDEN.
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Old 12 November 2009, 23:28   #38
Paul_s
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In my yoof when I bought an FPU for my 1200 I thought it had water inside which floated something like a duck.

Seriously that is what I thought at the time.

Don't worry about me, I do that myself on your behalf
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Old 13 November 2009, 00:52   #39
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paul I`m the opposite If people worry about me then I don`t have to

Get an FPU, fill that card up, then you know you can run that software that requires a fpu, even if you never do

I`ve always had a fpu just for completeness and one day I might do some ray traceing
or actualy workout the value of Pi yum yum
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Old 13 November 2009, 00:58   #40
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Quote:
Originally Posted by alexh View Post
Only if it is compiled with a C-compiler which supports FPU extensions or uses an external math library which in turn was made with support for FPUs.

Otherwise floats and doubles are just emulated using fixed point.


Possibly, but most software written in C for Amiga isn't compiled for FPU. The reason being compatibility.
Well you have to target the FPU of course I was pointing out the speed difference of a softfp library vs hardware float/double on lattice. This was on the Atari.
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