RAM Upgrade from PC3 10600 (1333MT/s) to PC3 12800 (1600MT/s) for an Elitebook 8440p

[ripperkid]

Hi HP Community 

I want to upgarde the RAM capacity on my HP Elitebook 8440p from 4Go (2Go*2) to 8 Go (4Go*2). Knowing that the last capacity is the maximum allowed for this laptop .. the problem is i'm a little bit confused with all the following values i found in the specs of each component :

- The Intel Core i7 620M specs says that the memory types that should be used with this processor is DDR3 800/1066 which corresponds to a PC3-6400 and PC3-8500.

- I found a 2*(2GB 2R*8 PC3-10600S-9-10-F2) Hynix RAM in my laptop .. --> 10600 is higher than 8500 

- A friend gave me a 2*(4GB PC3-12800) to upgrade my RAM capacity .. but 12800 is  higher than 10600 i found installed

I want you to tell me if this upgrade is feasable/Riskless for the laptop or should i buy the 4GB PC3-10600 and stay out of the troubles 

 Thank you in advance for your aswers 

[JeffHelp]

03/13/15 - Jeff reached out to customer

[bfldworker]

I do understand your confustion. It use to be easier 15 years ago when there weren't so many options available.

So to answer your question.

The fastest memory that your laptop can use is DDR3 10600. Now that doesn't mean you can't use 12800, 14900 or 17000. However you will not see any improvement with system speed. 

The numbers simply mean how many MB per second they will top out at.

DDR3 8500 will top out at 8533⅓ MB/s

DDR3 10600 will top out at 10666 MB/s

DDR3 12800 will top out at 12800 MB/s

unless you are using this laptop for gaming, or scientific calculation you will not see a vast difference between 8500 and 10600. 

Also you can mix and match DDR3 that have difference speed ratings. If you have 1 stick of 4GB DDR3 8500 and an other stick of 4GB DDR3 12800 the computer will notice the difference and lower the faster ram down to that of the slower ram.

However if you put a 4GB stick and a 2GB stick in you will lose what is known as Dual channel. Which is a whole other world of explaination. I will keep it simple.

In your case your laptop can run in what is known as Dual-Channel and Single channel ram configuration.

Dual channel is when you have 2 sticks of ram with identicle size (Speed really doesn't effect the avalability of dual channel), single channel is when you have either 1 stick of ram or 2 sticks that are different size.

Think of it as a road with 2 lanes. When you are running Dual channel both lanes are open, traffic is running smoothly

Single channel is like a 2 lane road with one lane closed off. You can still go both ways but you have to wait for the other car to pass before you can go the other way.  Just a note,

When it comes to computers it can impact proformance of up to 27% if you use programs that heavily use memory, games for instance.  However if you use your laptop for office work (MS OFFICE), facebook, video watching then it shouldn't matter much.

I hope that helps

Depending on the computer you can see up to a 27% proformance increase if you are using dual channel. 

[ripperkid]

thank you very much for being patient enough to explain all this memory science to me .. i really don't have the words to express my gratitude .. i've understood that i can use any PC3 RAM and the laptop will ''downclock'' its speed to fit its max capacity, besides, i have to put the same capacity for both bars if i want to work with the two Channels mode and keep the 27% of performance.. well i think i choosed the ideal solution, which is two PC3's of 10600, with the same capacity (4Go) and even the same brand (Hynix), it works perfect.. thank you for your help once again  ..

[bfldworker]

Not a problem at all.