060 overclockers question

[Heiroglyph]

Please keep in mind that this is in the context of taking the CPU card components completely out of the equation.  Imagine the card can cope with it.

All chips can go a little over spec, but how much can pretty much all masks of 68060s handle with basic fan/heatsink cooling?

Is 66MHz pretty much guaranteed? (only 16MHz, I actually have an old XC marked 66MHz)

How far can you get at 3.3v?

Does 80MHz+ really require upping the voltage?

Thanks

[magnetic]

1. Nothing is "guaranteed" with Ocng especially on 15 yr old hw!

2. 80mhz is about the max poss afaik

3. Yes it does require voltage regulartor or whatever (ask Stachu)

[Damion]

Revision 1 (most common on old Amiga accelerators): 64-66MHz is almost a given at 3.3v, had one or two do 70, and a few duds that weren't stable past 55MHz. No idea what the possibilities are with increased voltage.

Revision 6 (last one): Known to do 80-105MHz. (Had an Apollo that would boot at 100MHz, but without recognizing RAM.)

No experience here with the other masks. :-)

[matthey]

All chips can go a little over spec, but how much can pretty much all masks of 68060s handle with basic fan/heatsink cooling?

Is 66MHz pretty much guaranteed? (only 16MHz, I actually have an old XC marked 66MHz)

No. You are lucky if an XC 68060 works at 66MHz. Most should work at 60MHz but even that is not a guarantee. I am assuming proper cooling and year round usage in a moderate climate.

How far can you get at 3.3v?

Does 80MHz+ really require upping the voltage?

I don't know. I have overclocked a CSMK3 to 80MHz where it started to have problems after warming up. It was the latest revision 68060 and 50ns memory so I don't think those are the problem. I also clocked the SCSI and motherboard speed separately so that wasn't the problem. I think it was probably the memory controller chip or accelerator logic reaching it's max and not the 68060 voltage but I may be wrong. It's been rock solid at 75MHz by the way.

[NovaCoder]

As far as I know all of the latest mask 060's can handle at least 100Mhz, the issue is what you attach it to (ie the processor board).

No doubt that a modern 060 processor board could be built that supported 100Mhz, shame the market is too small to support a production run.

[Cosmos]

Had an Apollo that would boot at 100MHz, but without recognizing RAM

Put a 96 Mhz crystal and the fastram will be ok !

[Cosmos]

As far as I know all of the latest mask 060's can handle at least 100Mhz, the issue is what you attach it to (ie the process board)

No.

68060 rev6 have 3 sub-revisions : -002, -004 and -006

Some -002 and -004 cannot reach 100 Mhz, don't know why exactly...

The best is the -006, I have two of them and they are working fine at 105 Mhz...

[Heiroglyph]

This is good info.

According to estimations on the Atari CT60 page, something like 70% of the first masks can do 66MHz.  Those are pretty good odds IMHO.

At what point do you find that you have to bump up the voltage?

If so, do you think that is due to the CPU or the board components?  The board could easily be the weak link, they are using very old technology.

The Replay daughter boards seem to be having good luck with higher speeds, but of course the components are new and very fast compared to those from 1996.

[Cosmos]

It's due to the CPU : for a small voltmod, I change the regulator from 3.3 to 3.5... Can help a lot for overclocking !

I remember a 71E41J -002 who refuse to run at 66 Mhz... I putted 3.5v on his ass et voilà : 96 Mhz ok !!

[Lurch]

No.

68060 rev6 have 3 sub-revisions : -002, -004 and -006

Some -002 and -004 cannot reach 100 Mhz, don't know why exactly...

The best is the -006, I have two of them and they are working fine at 105 Mhz...

Is the -006 at the end of the model number printed on the chip? I have a 100MHz crystal on it's way so going to give this a try.

Currently it's running at 80MHz, no great loss if it doesn't work.  If 100MHz is a no go then 96MHz would be the next thing to try?

[AppleIIGuy]

Is there any where you can find information about the 060 masks that doesn't require sifting thru hundreds of forum posts?
I just want to find out about my Rev 5 060 and if it is capable of speeds over 66 mhz

[NovaCoder]

Is the -006 at the end of the model number printed on the chip? I have a 100MHz crystal on it's way so going to give this a try.

Currently it's running at 80MHz, no great loss if it doesn't work.  If 100MHz is a no go then 96MHz would be the next thing to try?

Hiya,

Yep you have the latest mask with that baby, don't worry

Like I said above, it's not just the chip, it's also down to other things like the chipset on the card and more importantly the memory on the board.

Your board has a very rare 50ns SIM so it *should* be able to handle 100Mhz.

I recently upgraded my Blizzard from 75mhz to 80Mhz but went through 3 different SIM's to get it to go that fast (Blizzard's aren't so happy to overclock as Apollo's because of the way they talk to FASTRAM).

[paul1981]

Please keep in mind that this is in the context of taking the CPU card components completely out of the equation.  Imagine the card can cope with it.

All chips can go a little over spec, but how much can pretty much all masks of 68060s handle with basic fan/heatsink cooling?

Is 66MHz pretty much guaranteed? (only 16MHz, I actually have an old XC marked 66MHz)

How far can you get at 3.3v?

Does 80MHz+ really require upping the voltage?

Thanks

My Apollo was the 66MHz (factory overclocked) revision 5 XC68060RC50. At least I think it was revision 5. I wanted more speed so I tried 75MHz and it booted, but it would crash before completing the boot process. I could even boot with no startup-sequence and go into workbench that way but it wasn't long before it crashed. I then tried upping the voltage a little (thanks to Cosmos for the mod), but it made no difference in my case, so I un-did the mod. So I decided to buy a revision 6 latest mask 060, and clocked it at 80MHz. It worked first time and I've never looked back since.

I did measure the voltage on the (unmodified) regulator but I can't remember exactly what it was. I have a feeling it was higher than 3.3v...maybe 3.62v, so I'm not sure whether 3.3v would work at 80MHz. Then again, how accurate is my meter? It was only cheap and I've had it 14 years.
But looking at it from another perspective, my Apollo was factory overclocked so they could have cherry picked a beefier regulator pcb to begin with.

My advise, try overclocking without doing the voltage mod. If 66MHz isn't working for you, then you might want to try the mod. But grab the latest mask 060 if you can, as 80MHz makes a nice Amiga.

[Lurch]

Hiya,

Yep you have the latest mask with that baby, don't worry

Like I said above, it's not just the chip, it's also down to other things like the chipset on the card and more importantly the memory on the board.

Your board has a very rare 50ns SIM so it *should* be able to handle 100Mhz.

I recently upgraded my Blizzard from 75mhz to 80Mhz but went through 3 different SIM's to get it to go that fast (Blizzard's aren't so happy to overclock as Apollo's because of the way they talk to FASTRAM).

Getting excited now, thanks Nova :-) Will be interesting to see, would be good for 130mips?

Was thinking of adding a second SIMM socket now too, don't think I'll be able to close the case at the moment with all the stuff I've put in there :-/

So I would need to track down another 50ns SIMM... hmmm.

Will be having another go this weekend to fit it all in the case, as I'd prefer that :-)

Will make sure to post some video's too, rebuilt my workbench (again) and have it on a faster 8GB CFCard.

On PFS3 060 the 1200 boots really fast. Only downside I've seen with PFS3 is copying a large amount of files, even under winuae I get it were it stalls or get buffer i/o errors.

Anyway off topic now :-)

[danbeaver]

They made EC chips for embedded applications that were factory rated at 75 and 100 MHz. I have a 75MHz is a box somewhere.