Cyberstorm MKI upgrading the 68060 from 50mhz to 75mhz?

[matthey]

I also recall that some of the early 68EC060 chips were full 68060s. They were probably rejects of the full mask. The later 68EC060 processors received their own mask (which was shrunk so should allow rev 6 clock speeds) which are highly unlikely to have the missing FPU and MMU. IMO, save yourself some trouble and stay with a full 68060 even if it's a little slower. Nova Coder's 3D ports need the FPU if that is the reason for wanting to overclock now.

Well, ignoring this particular Chip, is it possible to overclock, or get a faster clocked CPU for it, and if so, is that all that is needed, the chip and the oscillator?  (or if just overclocking, the oscillator is all that's needed?)

It depends on the accelerator and the amount of overclocking. The oscillator can affect the timing of the CPU, memory, Amiga chipset speed and I/O bus, and various chips on the accelerator (some of which have a rated maximum speed and temperature which increases). Some accelerators have multiple oscillators or locations for them to be able to independently clock the different pieces. Some accelerators use frequency dividers for the different pieces and don't tolerate changing the oscillator much at all. You can get some overclocking tips from this web site:

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

I think I have one of the earlier 68060RC50s, I'll post the cpu info tomorrow, but if I recall it was one of the first revisions.  It does have a heatsink and a fan on it.

Most of the early revision 68060s will clock to 60MHz which is worth trying. I haven't heard of an overclocked CSMK1 but there is a good chance that the accelerator and CPU will tolerate it although SCSI modules or SIMMs may not.

[matthey]

Well, that actually is why I initially looked into it, but eventually I want to start programming on it, so less compile time the better.  Quake 1 is almost playable at 50mhz.

Nova Coder's Quake II is very playable with 68060@75MHz on a gfx board. My XBOX360 nephew played it with no complaints about the speed (just the controls). A gfx board helps some but not as much as glQuake where I get 640x480x16 25fps on a Voodoo 3 or 4.

I had found that site before, but as I said in the original post, no info on overclocking the MK1.  Not sure if I want to be the guinea pig...

There is overclocking info on CSMK2 and CSMK3 but I have seen none on the CSMK1. I haven't seen any on the QuickPack 060 accelerator either which would also be interesting.

I don't have the SCSI module, and at least half the SIMMS are brand new.  I'd rather not overclock it, but get an actual CPU that runs at that, and swap the crystal out.  But you're right, there could be other components that are set with specific timings.

Most Rev 6 68060s are marked 50MHz and there are people overclocking to 100MHz or more. I wouldn't put to much value in the 68060 clock ratings. Some SIMMs are more overclockable too. The faster timing SIMMs can usually be overclocked more but there are some with rather slow markings that will work at 50ns. It's unlikely to harm the SIMMs or CPU itself by overclocking. A more likely problem is the memory controller chip but there is usually enough tolerance to allow a mild overclock. There may be a jumper or flash memory setting to increase the wait state if the memory can't keep up. I would expect a new 60MHz oscillator only would have a 90% chance of working and give a 20% CPU speed boost. Memory becomes faster too if you don't have to add a waitstate. The custom chips and I/O may be overclocked which gives a speedup but can cause problems with motherboard memory. AGA seems to be more over clockable than ECS but 60MHz should work in both cases. It's good to monitor the temperature of the chips and provide adequate cooling. Aggressive overclocking can be tricky but mild overclocking is generally pretty safe (accelerator manufacturers did it sometimes).

P.S. You could always buy an fpgaArcade with the 060 add-on board if you don't feel safe attempting an overclock on the CSMK1.

[matthey]

I do have the Radeon, I was trying out the AGA version of Quake 1, which suggested at least a 66mhz 060.  Quake2, I think suggested a 75mhz one.

Nova Coder made an RTG version of Quake II. Using the gfx card saves a little CPU time of doing the C2P so you should probably give that a try. I expect it will be slow in combat but you should be able to explore at sluggish speeds. Upgrading to 68060@60MHz might bring it up to somewhat playable speeds.

I wish I could get glquake working on it, but from what I understand only the Voodoo is supported?

That is correct. There is currently no AmigaOS 3.x drivers for the Radeon. You could get a used Voodoo 3 card. The speed of the Voodoo 3 3000 with SGRAM is comparable in 2D speed to the Radeon and offers 3D. You shouldn't need the memory with 128MB on the CSMK1 although you can leave both cards in.

Is the FPGArcade out yet?  I was kind of looking into getting one, but last I looked, it was still in development.

Yes, the fpgaArcade is available and shipping. The 68060 add-on board is not available yet though. That is what I'm waiting on too .

So the question is though, would I need to just swap out my crystal with a 75mhz one?  

Unlikely. The accelerator is likely feeding the clock back into the motherboard which would cause it to be overclocked to 75MHz and is unlikely to work without changes. The memory on the accelerator and motherboard may become a problem without adding wait states or changing to faster memory. My CSMK3 68060 runs at 75MHz but it has room for 3 oscillators and I feed the motherboard and SCSI with the original 50MHz. I had to cut a trace and add a 2nd oscillator for the CPU and memory to be clocked from. The high clock speed Apollo accelerator guys also have to modify the accelerator to clock the memory at 1/2 speed (and maybe the motherboard). It's not a good idea to overclock in one big step from 50MHz to 75MHz either. It's better to go in small steps while looking for problems like hot chips, timing issues and memory errors. Maybe now you see why I said that aggressive overclocking is tricky compared to mild overclocking.

[matthey]

The question is what is the difference between a 50Mhz & 60Mhz version besides the markings on the chip. What I need to know is what changed on the inside as both chips seem to overclock the same. This is probably why most users go for the 50Mhz version as there are unable to get more out of their card with a 60Mhz version.

50Mhz version are also easier to find too as well as being cheaper.

What users need to be aware of is what is marked on the outside is not always what's on the inside.

The 60MHz rated 68060s may have additional testing done to verify the higher clock speed but they probably came from the same batch of processors as the 50MHz parts with the same mask. The 50MHz rated parts are more of an "unknown" while the 60MHz parts should be better on average than the rest of the batch as they should be test verified picks with the rejects marked as 50MHz. All the comparisons are thrown away when going to a new mask though. The rev 6 was a die shrink where the 50MHz parts will outperform the old mask 60MHz parts in practically every case. Motorola could have easily marked the rev 6 as 75MHz but they had already decided to kill the 68060 (for PPC) for everything but embedded and military applications where there was less advantage to marketing the higher clock speeds.