RAM which to choose?

I need to buy extra RAM for my laptop and have noticed that some look different from each other, even though they have the same specification.

Does it matter if they look different or should they look the same in order to work properly?
I need extra type of DDR3 SDRAM PC3-10600, 666 Mhz

 

They might look slightly different but DDR3 is DDR3. The only real difference is the speed.
Ensure it's DDR3. The key notches are located differently in DDR, DDR2 & DDR3.

https://en.wikipedia.org/wiki/DDR3_SDRAM

 

I scanned my laptop with Speccy and the information it gave was the one I wrote in my thread, but when looking at some online shops they even mention number of pins, something that I can't find info on my existing RAMs. I did a scan also with Crucial but it only suggests a couple to buy, not the technical info.

Also some RAM blocks look different even though they have the right spec I am looking.

The first picture looks exactly as I have it.

 

You told us what RAM you need... rolleyes

 

Its not the matter of buying the cheapest, but getting the correct one. As pictures clearly show there are different sizes but with same spec.
By the way thanks for nothing.... usually one should not reply if they have nothing to contribute

 

Spare the attitude. You haven't contributed anything.
And you're confusing desktop RAM with laptop RAM, which would not have happened had you followed JoeRay12's good advice...

 

Obviously, the physical length, pin count and pin configuration must be the same. But other than that, they can be different and still be compatible. However, to ensure optimal performance it is typically desirable for them to have the same timings and size too. If different size or timings, dual channel mode may not be enabled and total RAM speed will default to the speed of the slowest module.

That said, more RAM trumps those issues.

You might try running Speccy (from the makers of CCleaner) to view the specs of your current RAM.

 

Thís is the RAM you need, as in the first image you posted. The second image is Desktop RAM. You have a Laptop. Ensure you order Laptop RAM, preferably the fastest your PC can accommodate.

 

The PC may also be capable of PC3-12800 SODIMMs. Given the choice, I'd take a lower CAS latency despite a module utilizing a lower frequency, but that's just personal preference.

I'd trust a Crucial scan's suggestions...

 

We probably would have been better off with some system specs.

You have to be careful with faster ram too. On my old laptop, it supported 16GB but only if you used slower DDR3. In the world of laptops, I don't think the speed differences will really be noticed.

 

I have always gone to Crucial. I write down exactly what it says.
I have swapped out RAM in three notebooks and 2 netbooks. (Limited slots so you can't add you have to replace).
I have added or swapped out RAM on 5 or 6 desktop computers and I have never had a problem by purchasing RAM based on the specs that I've gotten from the Crucial site.

I might have purchased memory from Crucial once or twice but I either buy off the shelf at BestBuy or order from NewEgg.