Can I install a 8GB ram stick with already installed 4GB RAM stick?

Hi Guys,
I have purchased a new laptop (Dell 5459 Core i7 6500U, 4GB RAM). I am planning to upgrade its RAM to 12 GB by adding one more 8GB ram stick on its second empty slot. Problem is, I have read many threads and some say that both RAM should be of equal size and some say they should be of same speed. I am also confused with the term speed. Is it 1600MHz or the number written like 11-13-B4.
Details of my Laptop Chipset Ram slots:
Slots: Two SODIMM slots.
Type: DDR3L
Speed: 16MHz
Configuration Supported: 2GB, 4GB, 6GB, 8Gb, 12Gb and 16GB.

Details of my 4GB stick:
Samsung 4GB 1Rx8 PC3L - 12800S - 11- 13 - B4

I was thinking to buy following slot:
1) http://www.flipkart.com/kingston-va...37&srno=p_2&query=ddr3L'&otracker=from-search
2) http://www.ebay.in/itm/Corsair-8GB-...670724?hash=item35f89350c4:g:Q4QAAOSwQTVWAkKn

Can you please help me in deciding which one should buy? Will these work fine or should I go with some other?
Please let me know if any other details are required.

Thanks

 

It will resort to the slowest speed and timings between the two. It's DDR3L and try to get same speed 12800. Stick with name brand RAM and you should be OK.

 

Almost all name brand RAM has lifetime warranty if it is/becomes defective. I wouldn't buy from ebay though (even at 99.99% off retail prices), but that's just me.

I see your system is DDR3 RAM (in your other thread I recommended DDR4 - ignore that part over there).

I would highly recommend to install two identical 8GB modules on your platform. A 2x 8GB 'kit' will ensure the best performance with both sticks installed, but 2 single 8GB modules will also work better than your existing 4GB stick + an additional 8GB stick (of any brand). Your platform and processor deserves matched RAM modules to perform at it's best. And any (small amount) of money you'd be saving is not relevant over the expected lifecycle of the notebook (at least 5 years or more - if not to the original owner, to the second, third and fourth one...).

After testing the new RAM as I indicated in your other thread, you can always sell the original 4GB RAM module and get back some of the expense of the second 8GB stick you buy.

Good luck.

 

Mixed size RAM modules will run in asymmetric dual channel. I've never quite figured out how that works but it's probably that, in an 8GB + 4GB configuration, the first 4GB of the 8GB module runs as full dual channel and the second half of the 8GB module is single channel. However, it works, the result is quite acceptable.

Two RAM modules is better than one for the integrated graphics which uses the system RAM.

John

 

I've run systems with both matched RAM sticks and un-matched (Size and speed) to test the difference and I really didn't notice any. I don't doubt that symetrical RAM, which can both run at full, dual-channel speed, would be theoretically faster but I just didn't notice any appreciable difference when I tested it. My main system uses non-symetrical, 4+8GB RAM and it has held up for the past two years and given no trouble.

I've purchased a fair amount of RAM from ebay but chose known brands and they all worked fine. The usual caveats to ebay still apply but anecdotal evidence suggests favourable odds when buying RAM.