Overclocking a Blizzard 1260

[liviux76]

Hello all,
I recently got a great Blizzard 1260/50 and it has been already overclocked at 66MHz.

Even if the CPU is a Rev.1 it is absolutely stable (with good heat sink and cooler in my Fractal R4 Case) and I was thinking to try to overclock it a little bit more.

I am going to receive a 72MHz 14pin DIL Crystal Oscillator and I will try to use it instead of the 66MHz 14pin DIL Crystal Oscillator.

I have only a doubt.
I will be able to see if it is stable or not just "stressing" a bit my system (compressing big directories, playing 3D games or so) but my question is: doing so, do I risk to damage somehow the CPU?

I mean, if it goes "too fast", is it possible that it get damaged and that going back with the 66MHz 14pin DIL Crystal Oscillator the CPU doesn't work anymore or has some problems?

Sorry if my question sounds a bit silly but I have no experience of overclocking...

Thanks in advance for any reply/advice!

[zipper]

It probably just crashes if pushed too hard, I'd expect no damage at least if tried not too long. The FPU part is the first to crash usually.

[liviux76]

Originally Posted by zipper

It probably just crashes if pushed too hard, I'd expect no damage at least if tried not too long. The FPU part is the first to crash usually.

Ok, thanks... so a program that uses FPU could be a good "tester", right?

[fitzsteve]

It should be possible to go to 72/75 or even 80mhz but you might (probably will) need a Rev6 060 however some boards like my old 1240T wont go to those speeds, for example above 75mhz was my limit.

I would imagine prolonged overclocking can damage the logic of the card, this is certainly the case in CSPPC's, the CPLD's on those seem to overheat easily.

The Blizzy's seem more robust but to prolong the life of you card you might consider some cooling to the logic chips or just stick at 66mhz which already gives very decent performance.

[liviux76]

Originally Posted by fitzsteve

It should be possible to go to 72/75 or even 80mhz but you might (probably will) need a Rev6 060 however some boards like my old 1240T wont go to those speeds, for example above 75mhz was my limit.

I would imagine prolonged overclocking can damage the logic of the card, this is certainly the case in CSPPC's, the CPLD's on those seem to overheat easily.

The Blizzy's seem more robust but to prolong the life of you card you might consider some cooling to the logic chips or just stick at 66mhz which already gives very decent performance.

Hi Steve, nice to see you!
Yes, I've read that Rev.6 are much better for overclocking, I've also read somewhere that Rev.1 like mine couldn't be overclocked at all but actually I can say that it works perfectly clocked at 66MHz (but I'm cooling it very well).

As you said the speed boost from 50 to 66 is already great, I was just curious to see if I could obtain some more boost but, at the end, I think that I will stay whit the 66MHz Oscillator. If it is safe as it seems, I will just test the card for a little while with the new Oscillator and then, maybe, I will give it to someone with a Rev.6...

[voyager_1701e]

Livio, is the change to 66Mhz as simple as using a new crystal?

[hese]

Originally Posted by voyager_1701e

Livio, is the change to 66Mhz as simple as using a new crystal?

Yes. You may need to add cooling though.

[liviux76]

Originally Posted by voyager_1701e

Livio, is the change to 66Mhz as simple as using a new crystal?

yes, it is.

My friend cpiac64 replaced the original oscillator and soldered a DIL 14 pin socket on my card where I can easily insert any crystal I want.

As I said I am now using a 66MHz oscillator and the "score" in sysinfo increased from about 38 MIPS to about 51 MIPS!

Cooling is necessary, though. I tried to use the card only with a heat-sink passive cooler but after a few minutes I had some errors (for example songplayer crashed, and so on...). Adding a fan on top of the cooler did solve any problems.

[gazj82]

I am sure I have asked this somehwere before. I have the following card running at 28mhz, could I just replace the crystal to achieve 33 or even 40mhz. Seems like they were released at these speeds also.

http://amiga.resource.cx/exp/cobra

[Sandro]

please note in the blizzard overclocking further than 66mhz the scsi controller will not work
that's not a problem if you are using ide hardisks or ide to cf adapter

[liviux76]

Originally Posted by Sandro

please note in the blizzard overclocking further than 66mhz the scsi controller will not work
that's not a problem if you are using ide hardisks or ide to cf adapter

Thanks for the info Sandro, I don't have the SCSI controller but I thought that it would have worked only at the original clock. That's good info if I would ever find a cheap SCSI controller...

[cpiac64]

Originally Posted by gazj82

I am sure I have asked this somehwere before. I have the following card running at 28mhz, could I just replace the crystal to achieve 33 or even 40mhz. Seems like they were released at these speeds also.

http://amiga.resource.cx/exp/cobra

your cpu is 20mhz overclocked to 28, don't overclock any more

[gazj82]

Originally Posted by cpiac64

your cpu is 20mhz overclocked to 28, don't overclock any more

Thanks cpiac64, Didn't want to ruin the CPU by taking a wild stab in the dark. I shall leave it well alone.

[Daedalus]

Originally Posted by liviux76

Thanks for the info Sandro, I don't have the SCSI controller but I thought that it would have worked only at the original clock. That's good info if I would ever find a cheap SCSI controller...

Yes, the SCSI chip, RAM, CPU and glue logic all run off the frequency of the crystal on the accelerator. So changing the crystal affects everything. I've been running my 1260 at 66MHz for over 10 years now. Ugly as sin with a heatsink and fan cable-tied to it and a hole cut in the side of my tower for airflow, but it's pretty stable... At least, no more unstable than the machine is anyway... I never tried going beyond 66MHz, but given that SCSI was already very tight on timings and that faster RAM might be needed too, I just left it at that.

[liviux76]

Just an update...

Today I received the 72MHz oscillator but using it my system (OS 3.9) crashes immediately at boot (SetPatch Program Failed, etc, etc...).

So... this means that I will continue to use the 66 MHz oscillator...

[klx300r]

@ liviux76

I'd hold off on the overclocking as based on my experience with my Viper 060@50 with 060 v1 it was always happy at 66mhz but every time I pushed it over it worked ok for a week or two max before the hangups, & guru's started visiting
Maybe is you a get a v6 060 but with v1 I'd be cautious no matter how much cooling you have.

[Marmes]

if you want overclock there is only one on amiga 1200, the great apollo1260!
blizzards are not that good.

[mikele]

Why would you do it? Just for kicks? It's not worth it, your card has the value of nearly 500 EUR. If you want to push it to the limits in order to add some more frames per second in 3D game like Quake, you'd be better off with some crappy PC you can find for free in front of electronic waste container!

[liviux76]

Originally Posted by mikele

Why would you do it? Just for kicks? It's not worth it, your card has the value of nearly 500 EUR. If you want to push it to the limits in order to add some more frames per second in 3D game like Quake, you'd be better off with some crappy PC you can find for free in front of electronic waste container!

You are right, there is no reason to push it too far.
I was just curious to see if the cpu could run faster than it was meant to.
However I think that the overclock from 50 MHz to 66 MHz is worth it. I have the same stability but the system is quite faster and I can notice it using a browser or YAM or songplayer and so on...

[liviux76]

Originally Posted by klx300r

@ liviux76

I'd hold off on the overclocking as based on my experience with my Viper 060@50 with 060 v1 it was always happy at 66mhz but every time I pushed it over it worked ok for a week or two max before the hangups, & guru's started visiting
Maybe is you a get a v6 060 but with v1 I'd be cautious no matter how much cooling you have.

Thanks for sharing your experience. I have been using my Blizzard (060 rev. 1) clocked at 66 MHz for about 2 months and I confirm that it works well and I decided not to push it further... ;-)