Thought everyone might like to see this... GVP G Force 040 combo board with adapter and rev6 060 , 80 MHz and GuruROM with SCSI2SD. Pretty sweet for a hack job. Have a second one I am giving the same treatment.

Not sure why the write speed to RAM is so slow. Assume reading is burst and writing is not? Pretty sure the combo cards are not 64 bit interleaved, just straight 32 bit data path...

Latency on AIBB shows 10.4, which is pretty high, but it feels super snappy.

CPU runs nice and cool, support chips are a little warm. Tried a 22 MHz crystal to no avail, have a few obscure frequencies inbound to see if I can get just a hair more out of the setup (20.088; 20.48; 21.00; 21.384).

Any ideas or hints on making it better, let me know.

No real effort on my part; bought it already socketed on Amibay.  The real trick on my other one is that I plan to solder the 060 adapter (lower half of the stack) direct to the card.  I will have to flip the resistor packs to the back side (the ones that run along the lower edge of the socket).  The most recent iteration of the 060 adapter, the one with the cutout for the regulator, and made with sockets, is low enough to clear the drive tray tab with about 2-3mm to spare even with the socket still on the accelerator.  The intent with soldering the adapter to the card is to recover about 5mm of height.
 
 Right now, I just mounted a 75mm squirrel cage blower on a universal drive tray and mounted it to the floppy holes.  Under-volted from 12v to 5v for noise reduction.  It almost perfectly blows over the CPU and associated circuitry.

Nice MIPS! But I imagine she's pretty noisy with such a fan installed...

Fan is actually VERY quiet.  It was only a .26 amp 12v to begin with.  I am running at 5v, and was thinking seriously of bumping to 7v (across the +5 and +12 as mentioned above), as the noise does not really become noticeable till 12v, and the extra airflow would be nice.  A while back I replaced the power supply fan with an 80x80x38mm (vs. 25MM).  I undervolted it from 12v to 5v, and with the deeper blade pitch, it seems to move more air quieter than the original.
 
 I have a CV643D, one of the later ones with the with the Virge DX chip, and would like to give it a benchmark run in place of the GBA-PII++ with the 060 to see how CPU limited it was on some of my older 040 benchmarks.  Maybe this weekend.
 
 Curious to see if I can get even a few more MHz out of the setup when my oscillators show up next week.
 
 I really want to fix the memory write speed, but have a sneaking suspicion it is just a limitation of the board design.
 
 All those curious undocumented jumpers again...

Finally hit the limit with a 21 MHz oscillator for a top speed of 84 MHz (around 111 MIPS on SysSpeed).  That will do for now.