Quick question - RAM config

[Dantai]

Alright this is whats up up guys.
Ir recently got my hands on
2 x 2GB OCZ Platinum-1066(PC2 8500) 5-5-5-18 2.1-2.2v DDR2

But I also have a old pair of
2 x 1Gb OCZ Gold-800(PC2 6400) 4-5-5-15 1.8v DDR2.

System Specs.
2.4GHz Quad Core 2
Asus P5KC
BFG 9800 GT OC2
500 GB HDD + 400GB HDD
500W Power Supply
Windows 7 Ultimate 64bit

My question is this should I remove the old ram and just have the new 4GB of ram in my PC, or should I just add the ram to my PC to get an overall 6GB. I am trying to get the fastest configuration, but I'm not a 100% sure what to do with the old ram.

 

[jsc]

Configure your system for the 4 GB of RAM. Then plug in other 2 GB.

Because the DDR2-1066 RAM needs looser timing and higher voltage, there's a good chance that all four sticks will work together. Then once the system is up and running, you can try tightening the timings and lowering the voltage.

The DDR2-1066 RAM is slightly slower. 6 GB of slightly slower RAM will contribute more to a responsive system that 2 GB of slightly faster RAM will.

Try to use all thew RAM.

 

[saint19]

Ok, the firts point here is this:

1- The difference in performance between 800 and 1066 is really small, so with 4GB to 1066 or 6GB to 800, you should get a performance too similar.

2- If you install the 2x2GB at 1066 and the 2x1GB at 800, all the 6GB will run at 800, or if you want that the 6GB run to 1066, you need overclock the 800 to 1066.

3- The voltage of the 1066 is too high for a DDR2 memory.

 

[Dantai]

Alrghty this is what i did so far I have all the sticks in and locked it at 800MHz, but I set the the timings to 4-4-4-15. Everything seems stable so far, but I honestly have no idea how to set voltages...

 

[saint19]

Look in the BIOS for something like this: http://www.pcstats.com/articleimages/200811/msiK9a2pt_bios2.jpg or this http://media.photobucket.com/image/BIOS%20RAM%20voltage/acinside/Msi_p35_neoF/E45bios_6.jpg or this http://www.overclockers.cl/reviews/2006/dfi_rdx200/images/bios_1.jpg
and the option Memory Voltage, or DRAM voltage