Need explanation of the CPU and FPU technology on turbo boards

[kidkoala]

@amigamenace

hehe, that whole post wasn't targeted at you..

i just get a little irritated when people can't stick to the benefit of the topic when we've clearly gotten to the point in the thread (within the first 10 posts or something), where everybody (i thought) knew that an fpu is not a vital component, and then goes on and on saying over and over again that it isn't. i just can't understand why someone wants to keep on like that..

[kidkoala]

@dr_righteous

hehe, that's a cool view on the matter..i guess pc's maybe managed to use fpu better in some way, back then..

@amidude

i'm gonna lighten up on you, when you start posting relevant stuff

[kidkoala]

hehe..it's the first time i've heard someone say something like "you're just a rookie" since high-school or in some b-movie or something, that lightened me up

i was ofcourse talking about relevant stuff in this thread..
again, please don't post more unrelevant stuff, ok?


 

[kidkoala]

i'm not telling you to stop posting, i'm telling you to post things that benefit the thread more, and not things that already are said, that's all. please don't feel affended, it's just positive criticism..

ofcourse i can't make you stop posting other stuff, but then everybody else has to scroll like mad to get to the interesting parts

[kidkoala]

please, let the next post be an informative topic-related one and i'll scroll right down to it and maybe respond as well!

[kidkoala]

hehe i guess that sums you up..

[kidkoala]

@derringer3

great, one who has thoroughly tested this and has proof of performance, hehe what kind of miggy and turbo board are those chips mounted on? cause my previous opinion is that when you have a big difference from the cpu to the fpu, the fpu needs to wait for the cpu to feed it all the time, you seem to have the opposite experience..
i'm going to try the same thing with my sx32@40mhz and fpu@33 w/oscillator@33mhz, here the cpu is faster in hertz, but if the fpu can finish it's job in less cycles cause it has more calculation-power, it will speed up the process (given there's something 3d-related calculations to do ofcourse).

@hammer

is it the same (or similar) with the gpu's now, and memory, as it is with the linear increase of cpu-performance; doubled every 2. year or something? i've always been fascinated with that, but i guess it's about to change because the new architecture with low-power, multi-core etc. breaks the linear curve?

[kidkoala]

@donnyemu

great you come up with this kind of post, it's just what i want

"The point I am making is it's more worthwhile to get an accelerator that combines the FPU and CPU with memory. That's where you'll get your speed increase and programs that really take advantage of the special math operations.. " what do you mean by this, where does memory fit into this?



@shoggoth

it's great with you're explanation to, but after hearing every meaning possible on just the matter you speak of, i'm having problems trusting anyone hehe, any kind of proof, documentation etc.? (i don't suppose you have this, it's just a question).

[kidkoala]

@shoggoth

thanks a lot! you've already been to great help, you seem to have a good understandig og the matter.

the atari-page (written by a norwegian i see, like me, interesting) was really something i've been eager to find, but never found. the overclocking-info is very valuable to me.

i have a cd32 w/sx32 (40mhz?) and a fpu @33mhz and a osc.@33mhz (the osc. has a dedicated slot on the accelerator,i bought the fpu and osc. together to upgrade my accelerator, i already knew before that, that an fpu wasn't needed for everyday use, it's just for the fun of putting one on:). what i didn't know is that you could put on any oscillator you want, and it will be overclocked! fun.
but where do you get osc. of up to 100mhz?? when i bought the 33mhz one, the biggest one was at 50mhz or something..
second, won't the fpu have a very shortened lifetime when overclocking it to 2-2.5x? i guess the cooling will help but anyway..

about the proof i wanted, it was just to see if you had any documentation or anything, i didn't recon you had any cause it's kinda weird old stuff to be tinkering with hehe, no offense intended towards you either..

EDIT: just found 64mhz oscillators on amigakit, they can just be fitted? i have to activly cool the fpu itself with a standard cooler also then?

what programs do i use to becnhmark this thing after being overclocked?

and also, how do i overclock the cpu on a sx32@030/40?
can i just replace the one i have with a 50mhz one? or should i just overclock the one i have? (i've read that you can often overclock, say a 33mhz to a higher level than a 50Mhz?

[kidkoala]

thank you for all the answers..appreciated..

one more, if you care to answer:

do you know anything about overclocking the 68ec020 14mhz cpu on the standard cd32? does it have a oscillator or is it oscillated by the motherboards own clock?

[kidkoala]

@hyperspeed

i know, this whole thing is very interesting and sounds like a lot of fun even trying and not succeeding would be quite fun

"the DAC's digital audio output sounds cleaner and less distorted." the 68010 sounds like a cool thing, if you could use a switch, i'm a little audiophile myself so getting even better sound from the beautiful sound coming from the amiga sounds like a dream:)

the fpu i have is the 33mhz 68882 so i'm probably going to buy it a 64mhz oscillator from amigakit and cool the beast down to normal temp. with some silver-paste, a big ol' cooling-grill(?) and a nice quite fan..

so the performance in games are only remarkable when a game is going slower than it should, but in raw performance in wb it should speed things up a bit?

[kidkoala]

@piru

i know, the performance in wb was cpu wise

overclocking anything that old would anyway be just for the fun of it, i remember overclocking my old pc's to the max (before watercooling and stuff like that, in the diy-overclocking days when buying silver-coolingpaste and polish down the cpu surface to the metal, to get better contact, that actually helped several degrees sometimes)

and i'm not sure that overclocking the fpu to the double won't have any effect, at least not in the benchmarks, wich have been documented to show great differences..

http://atari.nvg.org/fpu/ here's the link to the guy who has tried iverclocking the 68882 with atari's for a while, he says he ran his 20mhz at 50mhz for a long time (ok, he might not have used it all the time, but i guess he knows what he's doing). ofcourse you have to cool it down, and you have to use a 68882 not 68881, and you have to know the outer limits of your architecture (maybe the cd32 or the 600 can't handle more than 33mhz through the components though you can overclock your fpu/cpu as much as you want).

but this is the purpose of this for me, i want to know as much about it as possible and then i'm going to try it all out in practice ...for fun

this is a guy that's been overclocking since 1975 or something, i guess he knows what he's doing to, and he has some interesting things to say:

http://members.iinet.net.au/~davem2/amiga.html


"I have also found over the years that more recently made versions of a particular chip will often overclock to a higher frequency. For example you would be more likely to get better results from a 4 year old 68030 compared to one that is 7 years old. Likewise you will usually get less from a chip at the top of it's range compared to a lesser rated one. For example you will usually be able to overclock a 25MHz 68030 further than a 50MHz 68030.

Thirdly you need to bear in mind that the accelerator card itself will also limit maximum possible overclocking speeds. A good example is the Commodore A2630 which cannot be clocked past 29MHz - even if you install a 50MHz 68030 in it."

[kidkoala]

@piru, shoggoth

another problem could be cooling? if his fpu gets to hot it could possibly create bad data?

another thing: why does the cd32 have so many oscillators?
the one that's used for the 14mhz cpu i guess is the 28mhz oscillator (running at half speed)? and there's a 16,9mhz osc. around the area of all the video output, that's because video runs at 32fps and that the double of 16mhz?

wouldn't it be possible to overclock the cpu osc. or something then?

just asking..

[kidkoala]

hehe maybe an unrelevant example, but that guy who had been overclocking since 1975, that 1975 overclocking was his calculator, and when doubling the the clockspeed the calculator worked as usual but it calculated wrong answers

also, if you want the best of the best 68030 cpu, for overclocking-purposes (or whatever) you can order brand new 68030/50C from Rochester Electronics (i've just been mailing with the,), at the humble price of 144$ a piece, produced in 2002

[kidkoala]

who and when in th thread are you reffering to?

[kidkoala]

"I have also found over the years that more recently made versions of a particular chip will often overclock to a higher frequency. For example you would be more likely to get better results from a 4 year old 68030 compared to one that is 7 years old. Likewise you will usually get less from a chip at the top of it's range compared to a lesser rated one. For example you will usually be able to overclock a 25MHz 68030 further than a 50MHz 68030.

Thirdly you need to bear in mind that the accelerator card itself will also limit maximum possible overclocking speeds. A good example is the Commodore A2630 which cannot be clocked past 29MHz - even if you install a 50MHz 68030 in it."
------------------------------------------------------------

Quoting this _very_ experienced overclocker, I think that a
4 year old 68030/50 will overclock better than a 10-15 year old one, for more than one reason (better design, better materials, not old rotting electronics;).
But he also says that a top o' the line cpu will clock less than a smaller one, so I guess someone just has to try this out..
The Viper and similar accelerators were often sold overclocked, hence the problems with heat (in addition to generally bad design in some of them), I guess the 50Mhz were overclocked 42mhz or something..

Thirdly, like he says, is that the internal architecture of accelerators and motherboards often set a limit to the highest clockspeed a cpu can have, like he mentions the A2630 wich cannot be clocked to more than 29Mhz even if the 030 is 50Mhz..

A question then rises: What are the limits of eg. the CD32, the A1200, and the A600?