Biostar TZ68K+: Ram compatibility

I am planning to buy the Biostar TZ68K+. The cpu I will be using is the i5 2500k or i7 2600k, whichever I buy.
I already have two 4GB ram kits at home.
Corsair XMS3 DDDR3 2x2GB 1333 @ 1.65v 8-8-8-24
Transcend DDR3 2x2GB 1333 CL9 @ 1.5v (256M*8)

I think the mobo supports both of those rams individually. Right?
If yes, would I be able to use both rams simultaneously?

NO. Ram can be touchy from the same manufacturer with the same specifications.
In this case the memory chips are likely different (voltage and timing). on memory board controlers are different for certain, the voltage requirements are different for good measure.
For Ram to work together the on CPU or on motherboard contoller has to send and receive information at the same rate from each memory card. You may get away with close, but not this.
Each pair is going to ask for different voltage. With two pair 1.65 volts might work, information flow won't.

Boot with one set of ram, manually set your voltage to the higher of the two sets and your timings to the looser of your two sets, then add the second set and try to boot. Ive personally mixed brands and speeds of sdram, ddr1, and ddr2, it will usually work, but not always. And if it doesnt work for you, there has never been a better time to grab a 2 x 4gb set than right now

Supertrucker said:

Boot with one set of ram, manually set your voltage to the higher of the two sets and your timings to the looser of your two sets, then add the second set and try to boot. Ive personally mixed brands and speeds of sdram, ddr1, and ddr2, it will usually work, but not always. And if it doesnt work for you, there has never been a better time to grab a 2 x 4gb set than right now

Click to expand...

This. Its never recommended to mix/match ram, but it can work...

Thanks. I'll try that out on the mobo and let you know.
This mobo and cpu i'll be buying will replace my DP45SG and Q9550.
At what price can I expect to sell the Q9550 and DP45SG along with Transcend 2GB DDR3 1333mhz? I've used them for two years.

I now have a total of 8GB ram now. Using both the Corsair 2x2GB and Transcend 2x2GB and both run at 1.5v as of now.
Timings are 8-8-8-24.