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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Whitesnake on May 11, 2005, 01:43:26 PM
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Recently i've been looking into upgrading my Apollo 630 which is currently 33mhz + 33mhz FPU but i have a few questions.
Was there any Apollo 630's made with a 50mhz cpu and 50mhz fpu? I've looked into this and i found a picture of this board http://amiga.resource.cx/gallery/Apollo630.jpg
50mhz cpu but no fpu is this because there was no fpu's made faster than 33mhz for plcc?
I also did notice many Apollo boards with a 40mhz cpu and a 33mhz fpu i'm guessing the fpu can take the 7mhz increase in clock speed.
If i was to change my cpu and put a 50mhz cpu in is it worth removing the fpu? I did explore other solutions such as a plcc to pga converter so i could put a 50mhz fpu in but i'm not sure how successful this would be. :-)
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I'm sure there's 50mhz PLCC FPU's aswell though not sure if they are as common as the PGA ones. Anyway Vesalia sells 40Mhz FPU's that are claimed to handle 50Mhz though in an A600 I don't think it's ideal to overclock anything... at least not without both heatsinks and fans.
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Nope there are no 50 MHz PLCC FPUs, as the generated heat of the core would melt through the plastic caseing.
I also heard that the FPU has an impact on stability on A600 turbos, as the required signals that are taken from then 68000 are week to begin with and are even more stretched at higher clockspeed.
And really what software does require / benefit from an FPU that runs satisfactory speed on a humble 68030. You really don't want to do raytraceing on it do you ?
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Hey Yo!
So what would the fastest A600 be able to run at?
Regards
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It wouldn't be easy to upgrade your Apollo 630 to a 50 MHz one, since the cpu is soldered directly to the board. It isn't placed in any socket.
There were 50 MHz versions, but probably not many, since they costs too lot at the time they where released.
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Thanks for the info guys :)
It is a job for a steady hand yes but i'm prepared to do it :)
Should be nice to see some of these 68kasm Polygon based games improve from the mhz increase Wings,Frontier etc
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Before you get out the old soldering iron, you do know that most CPU's have absolutely no difference between speed ratings in terms of design.
They come out of the fab and each chip has slightly different wafer processing characteristics. Chips are hand picked for stability better speeds, based not on their design, but their chemical / physical ability etc.
If there are not enough of lower speed rated parts, they'll just use higher speed rated parts and brand them appropriately.
You may have a CPU capable of 50MHz soldered down already.
Instead of swapping to a different CPU, remove the FPU, add a heatsink & Fan and just change the Crystal Oscillator (the square thing on the bottom RHS) to a 50MHz part this will make your 33MHz chip run at 50MHz
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Pretty much all 68882s will run up to 50MHz but not more than that and you'd better cool the chip. As Lemmink implied, the plcc chips are inferior heat-wise to the more expensive ceramic pga design. The Apollo 630/50 I believe used pga chips for that very reason (even then it's hot as hell and you should add heatsinks and small fans to avoid crashes and let the chips live longer).
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Look at the Picture he supplied. It definately does NOT use PGA! There is an empty PLCC socket.
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The 33mhz cpu i already have is overclocked to that speed as the serial number has been rubbed off the cpu so i wouldn't risk any further overclock.