Performance and Lifespan of onboard memory vs SO-DIMM memory

[davidoc]

Hello.

I would want to know something about soldered memory vs proper SO-DIMM slots on an ultrabook (aka. Dell XPS 13, XPS 15, Asus Zenbook series, Lenovo X1 Carbon, X1 Extreme, etc.).

The majority of the ultrabooks I mentioned (especially the Zenbook series which I really, really like) have the memory onboard thus, it cannot be replaced or upgraded.

Ultrabooks, for example, Dell XPS 15 or Lenovo X1 Extreme have proper SO-DIMM slots, so if anything messes up, I can just replace a module or simply upgrade it.

When I look a the first ones (mainly 13"-14" screens) I feel a little "nervous" about the onboard memory.

I prefer buying an Ultrabook with the SO-DIMM slots, but the main inconvenient is these ones are usually more expensive.

So, my main concerns are:
Is that is there any real difference about performance on onboard memory vs SO-DIMM slots?
How about the "lifespan" of these soldered memories?

Thanks.

 

[Eximo]

They are literally the same chips, on a DIMM or SO-DIMM they are soldered to that board instead. With direct soldering to the board you eliminate the need for a socket/pin interface and, though not really important, some transmission time between the CPU and the memory.

Not like you can change out any of the other components either these days, basically just the drives and memory for quite a while. CPUs and GPUs on expensive models. The occasional expansion card.

Do you have the same concerns in a smart phone or tablet? Again, the same memory.