Different size rams Mix ?

Hi !
Im using win 7 home with DDR3 2x2GB 1666 / 12800PC3 .
I want to order 2x4GB 1666 / 12800PC ( but different brand )
Does it work ?
- 1 more question ^^
My HDD with 1TB 7200rpm and i want to insert 1 more 2TB HDD with different brand , too. Will it work? or do i have to do something like format ? or...
hope someone can help me this ! thanks alot


//////////////////////////////////// Other Questions /////////////////////////////////////

My sister wants to build a new computer , then i choose these compoments.
Detail with link also.
+ CPU : AMD x6 1075T
+ Mobo : ASUS M4A88T D-V EVO/USB3 AM3 AMD 880G SATA 6Gb/s USB 3.0 HDMI ATX AMD Motherboard
+ Case : Rosewill CRUISER Black Gaming ATX Mid Tower Computer Case with Side Panel Window and Four Fans
+ Ram : G.skill DDR3 2x4GB 1333
+ PSU : 650watts Rosewill ATX
+ HDD : 2TB western
+ Optical : CD/DVD burner
+ Video card : ??? still look for that .
hope these compoment are match...can you look at that please ! still missing a video card , do not know how to choose it with her budget like $60~$80

For the RAM you can, but you need two identical sticks in each channel ideally, so you'll have the 2x2GB sticks you have in now in channel A, then the 2x4GB sticks in channel B. If you built the PC yourself, then just look in the motherboard manual to check the RAM slot layout, but slots usually go |A|B|A|B| for channels.

The hard drive isn't a problem either. Just slot the new hard drive you want in, connect a cable to it and the motherboard, plug a power connector in and away you go. You might need to format the new drive once you're in to Windows, but you can leave your current drive as it is.

The RAM depends on your motherboard make and model. Look on the manufacture's website and get the QVL (qualified vendor list) for your moboard. Mixing of RAM also depends on the moboard QVL.

Mike

Ots86,
Chances are good like 60/40 that it will work but it's always better to take the time to see what the mobo manufacturer has tested and approved then it's less a guess. I've mixed ram before and gotten ok results but I think in a perfect world we all try to keep the ram sticks the same! Let's see how any others out there feel about mixing it up so to speak.

hi :) here is a link to a great free program from passmark called rammon it will help define your ram
PassMark RAMMon - Identify RAM type, speed & memory timings

also you can check how windows allocates your ram in windows with resource monitor
click start orb and type resmon in the search box (or copy and paste) and press enter on keyboard and in the search results click on resmon, and the window will open.

a rule of thumb is best to keep to the same manufacturer of the ram modules and size so then everything like in the timings will be identical etc.

here is a good site for establishing your ram with there download tool from crucial (Crucial System Scanner tool) just click on scan my system
RAM Memory Upgrade: Dell, Mac, Apple, HP, Compaq. USB drives, flash cards, SSD at Crucial.com

how much total ram do you want to use? example 8GB TOTAL = 4 sticks x 2GB= 8GB

also when you have installed the ram check that windows is using all the new ram to do this follow these steps

1. type msconfig in start menu box
2. clik on msconfig in results (system configuration window will pop up)
3. at the top of window click boot
4. click on Advanced options
5. there will be a box in the top right hand corner Maximum memory
6. make sure the box is un-ticked (this will allow windows to allocate all the ram you have installed)
7. click ok
8. click ok on system configuration box
9. reboot when promoted

that's OK no problem report back how you get on remember we are all here to help in the forum so feel free to ask for help ok:)

ots86,
Give us the full spec's of this second dead system and we can help. Hopefully the board/psu didn't take other components down with the ship so to speak.