RAM Types (Advice Needed!)

Hi again!

I am trying to decide the best RAM for a new Aopen motherboard. My previous question to this forum has led me to decide on using two or four 128 MB DIMMs (thanks everyone!). Now I need to fully understand the nitty gritty details with the assorted RAM types. Here is some information paraphrased from the Aopen manual:

"...This motherboard has four 168-pin DIMM sockets that allow you to install PC-100 or PC-133 memory up to 2.0 GB (or 1.5 GB when using FSB=133 MHz). The motherboard supports SDRAM, VCM and Registered DRAM. The driving capability of new generation chipset is limited due to the lack of a memory buffer (to improve performance). This makes DRAM chip count an important factor to take into consideration when you install DIMMs. Unfortunately, there is no way that the BIOS can identify the correct chip count, you need to calculate the chip count by yourself. The simple rule is: by visual inspection use only DIMMs which are less than 16 chips. DIMMs can be single or double sided. They have 64 bits data and 2 or 4 clock signals. We strongly recommend choosing 4-clock SDRAM for its reliability..."

And then it goes on to describe how to visually identify 2/4 clock and single/double sided DIMMs. Now, my understanding is that ECC RAM utilizes higher chip counts (18?) and latencies so I will first rule out using ECC. These questions should really help me understand the RAM situation for this motherboard:

1) What exactly is the 2 versus 4 clock thing?

2) How should 'single' and 'double' sided DIMMs factor into my decision making?

3) Is registered DRAM favorably comparable to SDRAM?

4) Is VCM really a bad buy considering price, performance and future compatibility?

5) Why do you suppose this manufacturer would strongly recommend using DIMMS with less than 16 chips?

6) Why do you suppose this manufacturer would strongly recommend using 4-clock SDRAM?

Finally, the motherboard does use 4-way interleaving. It also has PCI clock multipliers of x2, x3, and x4 for the final RAM speed. Consequently, the RAM can be clocked anywhere from 66 MHz up to 155 MHz dependent upon the FSB/PCI settings. Perhaps you overclockers can help with these:

7) Would PC-150 CAS-2 128 MB DIMMs be the optimum choice for performance and reliability?

8) Considering all these 'official' specs, what would you buy and what would you look out for when dealing with Mushkin or Crucial?

Any other helpful advice or tips would be greatly appreciated!

Thanks again! Sarah McIntyre
BladeFlash^aol.com