bryan@geo-works.UUCP (Bryan Ford) (06/19/89)
I was just wondering something. Would a coprocessor board using one of the
new RISC chips (Intel 860, Motorola 88000, AMD 29000, whatnot) be feasible
for the Amiga? I'm thinking in terms of fast ray-tracing.
I was just looking through the Am29000 user's manual (which they sent me
for FREE, along with all kinds of other good stuff...now that's what I call
support!), and it definitely looks fast! The other two mentioned above are
supposed to give about the same performance - about 36,000 Dhrystones. Of
course, for ray-tracing, floating-point would be used more than simple
integer calculations, but considering the Amiga 2500 can do a max of about
5000 Dhrystones with special compilation and a priority of 100, it looks
nice.
So what thinks y'all? If it would be a good idea, maybe we should start
'persuading' the hardware dudes to make something like this. Of course,
this would probably be quite expensive, but if you're doing lots of
ray-tracing, it might be worth it.
Anyway, just a little thought that crossed my mind...
Bryan
--
____________________________________________
_/ Bryan Ford - bryan@geo-works.geo-works.com \_
_/ ..!utah-cs!caeco!i-core!geo-works!bryan \_
/ ..!uunet!iconsys!caeco!i-core!geo-works!bryan \451061@uottawa.bitnet (06/29/89)
Bryan Ford <bryan@geo-works.uucp> writes in Message-ID: <0957.AA0957@geo-works> > I was just looking through the Am29000 user's manual (which they sent me > for FREE, along with all kinds of other good stuff...now that's what I call > support!), and it definitely looks fast! The other two mentioned above are > supposed to give about the same performance - about 36,000 Dhrystones. Of > course, for ray-tracing, floating-point would be used more than simple > integer calculations, but considering the Amiga 2500 can do a max of about > 5000 Dhrystones with special compilation and a priority of 100, it looks > nice. When comparing Drystones, indeed RISC technology seems fantastic, but the real world out there, including the simulated ray-traced world talks floating point. And on floating point benchmarks, the RISC and CISC architectures are on par. THe cost therefore to switch to RISC based systems the performance non- improvement. I am one of those who ultimately think that CISC will win the battle, but I better stop here, otherwise I'll end up writing three volumes about that. Valentin _________________________________________________________________________ The godess of democracy? "The Name: Valentin Pepelea tyrants may distroy a statue, Phonet: (613) 231-7476 but they cannot kill a god." Bitnet: 451061@Uottawa.bitnet Usenet: Use cunyvm.cuny.edu gate - Confucius Planet: 451061@acadvm1.UOttawa.CA
tim@crackle.amd.com (Tim Olson) (06/29/89)
In article <18689@louie.udel.EDU> 451061@uottawa.bitnet writes: | When comparing Drystones, indeed RISC technology seems fantastic, but the real | world out there, including the simulated ray-traced world talks floating point. | And on floating point benchmarks, the RISC and CISC architectures are on par. What data do you have to back up your claim? A look at the MIPS Performance Brief, issue 3.6, shows RISC processors consistently outperforming CISC processors on both integer and FP applications, including the Livermore Loops, LINPACK, Whetstone, and SPICE. [well, some of the high-end IBMs and AMDAHLs creep in there...] As far as ray-tracing is concerned, here are some of the statistics from a simulation of a ray-tracing program which are very interesting: ---------- Instruction Mix ---------- 1.11% Calls 10.54% Jumps 17.36% Loads 5.26% Stores 8.10% FP ops 0.12% Convert 0.04% Sqrt 0.00% Feq 0.09% Deq 0.00% Fgt 0.57% Dgt 0.00% Fge 2.37% Dge 0.00% Fadd 0.95% Dadd 0.00% Fsub 1.20% Dsub 0.00% Fmul 2.51% Dmul 0.00% Fdiv 0.25% Ddiv i.e. the FP-intensive ray-tracing program is really only 8.1% FP instructions; the remaining are the standard ALU ops, loads, stores, jumps, etc. -- Tim Olson Advanced Micro Devices (tim@amd.com)
DMasterson@cup.portal.com (David Scott Masterson) (06/29/89)
In message <00957.AA00957@geo-works>, bryan@geo-works.UUCP writes: >I was just wondering something. Would a coprocessor board using one of the >new RISC chips (Intel 860, Motorola 88000, AMD 29000, whatnot) be feasible >for the Amiga? I'm thinking in terms of fast ray-tracing. > Come to think of it, whatever happened to the talk of a Transputer board for the Amiga?? There comes a time when things have to be brought out regardless of price in order to give people the "warm fuzzy" that this system is going somewhere. What's the status of the Transputer and how does marketing viewing it?? David Masterson DMasterson@cup.portal.com
daveh@cbmvax.UUCP (Dave Haynie) (06/29/89)
in article <26165@amdcad.AMD.COM>, tim@crackle.amd.com (Tim Olson) says: > In article <18689@louie.udel.EDU> 451061@uottawa.bitnet writes: > | When comparing Drystones, indeed RISC technology seems fantastic, but the real > | world out there, including the simulated ray-traced world talks floating point. > | And on floating point benchmarks, the RISC and CISC architectures are on par. > What data do you have to back up your claim? A look at the MIPS > Performance Brief, issue 3.6, shows RISC processors consistently > outperforming CISC processors on both integer and FP applications, I think lot of it has to do more with how the various type of CPUs are doing floating point, rather than whether you're strictly a RISC or CISC CPU. The current bottom line I suspect is just what Tim is claiming; that RISC is currently outperforming CISC at floating point. But the reasons why make things a little more interesting. For instance, every CISC type device uses an external math coprocessor, and most of these are relatively low performance devices, like 68882 or 80387 chips. But they hook into the CPU with a bare minimum of support hardware, they extend the CPU instruction set in a standard way, and they're relatively cheap. RISC's taken two different approaches. Devices like Moto's 88100 and even the semi-RISCy Transputer have small by very fast on-chip floating point units (the 88k actually has two, one for add/subtract, one for multiplies). This is kind of a RISCy answer to floating point -- you make the basic floating point ops so fast, any more complex operations can be coded in software and still go much faster than their microcoded counterpart external coprocessors. The other approach is to hook up a simple but fast FPU externally; SPARC machines do this. Both of these techniques are as applicable to CISC as RISC, and they're both getting implemented as we speak. Weitek math chips can be hooked up to '030s or '386s just as easily as to any RISC machine, with similar performance increases (at a loss of the standard instruction set and register-extension model you get with the tightly-coupled coprocessors, though at least in the '386 world one Weitek chip is emerging as a second FPU standard). And both corresponding next generation CISC CPUs are bringing on-chip a small, fast FPU which works pretty much the same way that RISCy FPUs work. The '040s going to apparently do a floating point add in 3 clocks and a floating point multiply in 5. As Tim pointed out, there's lots more to a "FPU-bound" program than the actual speed of the FPU instructions, though I think pretty much from this year on, the integer speed differences will be more responsible for floating point differences between CISC and RISC than the true raw floating point speed. At least maybe until all the RISC parts start vectorizing like some fool Cray or something :-) > -- Tim Olson > Advanced Micro Devices -- Dave Haynie Commodore-Amiga (Systems Engineering) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: D-DAVE H BIX: hazy Be careful what you wish for -- you just might get it
bear@bucsb.UUCP (Blair M. Burtan) (07/07/89)
In article <0957.AA0957@geo-works> bryan@geo-works.UUCP (Bryan Ford) writes: >I was just wondering something. Would a coprocessor board using one of the >new RISC chips (Intel 860, Motorola 88000, AMD 29000, whatnot) be feasible >for the Amiga? I'm thinking in terms of fast ray-tracing. VLSI Technologies has a RISC chip set for serious graphics capabilities like Ray-Tracing. The poop-sheet has a nifty image on it. This might be a bit easier to incorporate into a card for the 2000 video slot. - Bear
bear@bucsb.UUCP (Blair M. Burtan) (07/13/89)
>Come to think of it, whatever happened to the talk of a Transputer board >for the Amiga?? There comes a time when things have to be brought out >regardless of price in order to give people the "warm fuzzy" that this >system is going somewhere. What's the status of the Transputer and how >does marketing viewing it?? > If you really want to get your hand dirty, Microway makes a T800 and a T414 board for the PC. If you've got a bridgecard, go for it. Maybe that'll spark some interest. - Bear