The results of the i820 systems are in:
1. The Aopen AX6C, an early 3-DIMM i820 solution, 2*256 PC800 RDRam + 1 C-RIMM
3Dmark2K: 8546
3Dmark01: 7406
Q3Ademo four.DM68: 140.6
Sisoft99: CPU 345 MB/s - FPU 378 MB/s
Quite the disappointment.
2. The Iwill Dual Slot 1 is a more mature system. I've tested just one 1,4 on a Slot-T adapter, although the Powerleap also works problem-free. It did not want to boot with 2*256 RDRam. So I did the tests with 1*256 and 1*128 (only two DIMM-slots).
3Dmark2K: 9803
3Dmark01: 8767
Q3Ademo four.DM68: 159.4
Sisoft99: CPU 446 MB/s - FPU 470 MB/s
Better, but still not worth the premium price RDRAM fetched in '99. Even the 1,4 Ghz, the final Tualatin released in 2002, does not benefit much from the larger bandwith RDRAM gives. The Tualatin is far better off with fast latencys.
and the only i840 I have:
3. Compaq workstation AP 550, i840, 4*128 RDRam
3Dmark2K: 10239
3Dmark01: 9540
Q3Ademo four.DM68: 162.8
Sisoft99: CPU 568 MB/s - FPU 589 MB/s
A lot better, and impressive results on the memory front.
Overclocking on these boards was either not possible due to BIOS restrictions (Compaq) or unstable, even at the lowest overclocking settings. 1575 (150 FSB) was impossible to achieve on both my i820 boards.