My bios does not provide any options for setting the mem timings. But seems the modules provide 4-4-4-12 when running at only 266 MHz. At least that's what CPU-Z tells me. And yes, I used CPU-Z before. It was the original reason for this thread. =)
Now one weird thing: I noticed that Windows only recognized 3070 MBs. Bios said the same, so I switched them around a little bit. 2 modules - dual channel - no problem. 3 modules - single channel - of cause. But after I switched no 3 and 4, my system noticed 4 GBs of RAM miraculously. And now they even run in dual channel. WTH?