Dual-Channel with 2x4GB + 1x4GB DDR3 RAM?

[Tordiato]

Hey guys

Right now I have only this 4GB RAM (Single-Channel):
KINGSTON 4,00GB 1333MHz DDR3, CL9 (9-9-9-24)

and I'd like to make an upgrade with +8GB RAM:
Kingston HyperX Savage 8GB (Kit 2x4GB) 1866MHz DDR3, CL9

Motherboard:
P8H77-V LE (LGA1155), Supports only Dual-Channel

(I've looked at this thread and it looks as the best option for the price that my local shop offers:
http://www.anandtech.com/show/7364/memory-scaling-on-haswell/10)

So my question is:
If I buy the kit with 2x4GB RAM, will it run in Dual-Channel or not? Since I want to use the old 4GB RAM too..
or is it more wise to get rid of the old 4GB RAM and use only the new ones(2x4GB) or even better to buy 8GB now and another 8GB (same model) later and get rid of the old 4GB?

Thanks in advance for your response!

 

[Roti-Kebab]

Hey guys

Right now I have only this 4GB RAM (Single-Channel):
KINGSTON 4,00GB 1333MHz DDR3, CL9 (9-9-9-24)

and I'd like to make an upgrade with +8GB RAM:
Kingston HyperX Savage 8GB (Kit 2x4GB) 1866MHz DDR3, CL9

Motherboard:
P8H77-V LE (LGA1155), Supports only Dual-Channel

(I've looked at this thread and it looks as the best option for the price that my local shop offers:
http://www.anandtech.com/show/7364/memory-scaling-on-haswell/10)

So my question is:
If I buy the kit with 2x4GB RAM, will it run in Dual-Channel or not? Since I want to use the old 4GB RAM too..
or is it more wise to get rid of the old 4GB RAM and use only the new ones(2x4GB) or even better to buy 8GB now and another 8GB (same model) later and get rid of the old 4GB?

Thanks in advance for your response!

It's better if you get rid of the old one, it will cause a lot of compatibility issues and another note is that, the speed of all ram sticks will be reduced to the lowest running ram stick in the system, so all your sticks would run at 1333MHz, best option here is to get rid of it.