Is this laptop's RAM single-channel or dual-channel?

[ThomasKK]

Hello,

I'm interested in this laptop: http://shop.lenovo.com/us/en/laptops/ideapad/700-series/710s/

In tech specs it says the laptop can have up to "Up to 16 GB LPDDR3 1866 MHz (Onboard)" RAM memory. I just wanted to know if the RAM is in single-channel or dual-channel?

 

[thx1138v2]

Yes, it is dual channel but you won't get the benefit of dual channels unless two memory modules are installed. It will run just fine with one module but it won't be operating in dual channel mode.

 

[ThomasKK]

Yes, it is dual channel but you won't get the benefit of dual channels unless two memory modules are installed. It will run just fine with one module but it won't be operating in dual channel mode.

Wait wait wait, so in this situation, as you said, there is only one memory module installed (1x8gb, 1x16gb for example?) and it works in dual channel? How is that possible?

I've always thought that single channel ram is only one stick, and dual channel ram is 2 sticks with twice as big bandwidth as one stick which allows better performance using integrated graphics since VRAM is taken from RAM module(s).

 

[jaguarskx]

Since the RAM is "onboard" it is soldered into the motherboard and there is no way to upgrade. I am going to guess that it only uses one RAM stick so it will be operating in single channel mode. Generally speaking when RAM is operating in dual channel mode it can increase game performance with integrated graphics by roughly 10% - 15% or maybe even up to 20% compared to single channel, but it depends on the game.

 

[ThomasKK]

Yep, i agree, i also thought "onboard" is only 1 stick, but every version of that laptop is written to have a dual-channel ram, according to notebookcheck.net

From my search:
Single channel = 1 stick
Dual channel = 2 sticks

So, if it's written dual-channel, shouldn't it have 2 sticks "soldered into the motherboard"?

 

[jaguarskx]

Maybe...

I would prefer a screenshot of CPU-Z showing how many sticks are installed. If it were my decision to design that laptop would have 1 stick of 8GB RAM or 2 sticks of 8GB RAM. A single stick of 16GB of RAM is about double the cost of 2 sticks of 8GB RAM.

 

[ThomasKK]

I was trying to find that too in review and usage videos, but i haven't seen it, sadly, going to keep looking :|

 

[thx1138v2]

I worked on a friend's Lenovo laptop and it had socketed RAM but it wasn't this model. His came from a big box retailer and it only had one module installed. It appears this model has sockets also.

http://laptopmedia.com/highlights/inside-lenovo-ideapad-700-disassembly-internal-photos-and-upgrade-options/

https://www.google.com/search?q=lenovo+700+ideapad+teardown&ie=utf-8&oe=utf-8

 

[ThomasKK]

Lenovo 710s's RAM cannot be upgraded, meanwhile yoga 700 can. I'm not sure if there is one stick or two sticks soldered into the motherboard without an opportunity to upgrade. Here are some CPU-Z photos taken from the last-gen model:
http://www.notebookcheck.net/Lenovo-IdeaPad-710S-13ISK-80SW0031US-Notebook-Review.168383.0.html (scroll down a bit)
But no "SPD" tab available, so can't see which slots are taken. But maybe other pages can say something about being single-dual channel?

 

[thx1138v2]

The "Channel #" field on the CPU-Z Memory tab states "Dual" so it is using both channels. I don't remember the exact word but when it's running one module in a dual channel system it says something different - I think "Interleaved" or something like that.

 

[ThomasKK]

Well, seems legit. Since '#' sign is mostly used with numbers. My desktop PC says the same '#dual' and on the next tab it shows my memory is installed on 'slot #2 and 'slot #4' - i will take this as a proof that 8GB in dual channel comes at 2x4GB.

Thank you for your help!

EDIT: I also found out that every slot of RAM has a 64bit bandwidth. In every Lenovo 710s version "TechPowerUp" app and "Graphics card" tab shows the bus bandwidth is 128bit. 64bit * 2 = 128bit => 2x4GB RAM => dual channel.