if you are considering upgrading RAM, how to find out what type of RAM is compatible swift sf314-56g

ed4myra

I put this post to help others looking for what type of RAM upgrade is compatible with their laptop, based on real-time scanning of their laptop's on-board memory, and not only on paper specs by the laptop manufacturer or the seller of the RAM.

I have an Acer swift sf314-56g model, and I know it is upgradable, because there is one slot available for upgrade. I want to upgrade the RAM. 

I have read that it is recommended to use matching RAM sticks, i.e. same speed/frequency, CAS latency, timing and if possible brand. The 56g model has one bank soldered, so this makes the options limited by the specs of the soldered RAM. There is no need to upgrade having better latency or faster RAM which is also more expensive, because they have to work in a dual-channel fashion, and the speed will be determined by the weakest RAM stick. Perhaps the side effect can be that the combination might not work, due to timing issues. See https://forums.tomshardware.com/threads/mixing-two-pairs-of-ddr3-sticks-with-different-latency-and-timing.1903265/. 

I have been looking at online tools, crucial.com and kingstonmemory.co.uk has one, however they are based on paper, using the laptop model id, and not based on a scanner program. I also know that the crucial advice is wrong for the sf314-56g, saying the memory is not upgradable.

I found here https://www.mrmemory.co.uk/scanner/microsoft-windows a scanner tool, which you can run and which inspects your memory banks in your laptop.

Please find the results for my laptop as an example:


At the bottom of the screen print you see the brands used (Micron, Hynix) and that the speed is matching 2666 Mhz. Bank 0 is the soldered bank and brand is Micron.

So the next step is to find out what is the CAS latency of a 4GB SODIMM 2666Mhz Micron RAM. I came across these specs:


Here you see, the timing is: 0.75 ns and CAS latency of 19 for the 2666 version.

I also read that Crucial is a brand of Micron, so they will use the Micron RAM chips. So here are the specs of compatible matching RAM sticks for my laptop:
Crucial brand, 8GB or 16GB can fit in the 56G model, CAS latency of 19, SODIMM format, DDR4 2666 speed, and non ECC.

If you go to crucial.com  you will find: https://www.crucial.com/usa/en/ct16g4sfd8266

So this RAM stick is matching, except that this stick is 16GB vs 4GB for the soldered one, so I can only benefit of 2x 4GB dual channel memory.

Note that your upgrade mileage will vary, but hopefully this post will be helpful in your search.

MaClane

Good afternoon ed4myra !

RAM issues are much broader than specifying slot availability or what certain tools might indicate.

RAM support depends directly on the processor control used and the chipset controllers.

Both processor and chipset may limit frequencies and capacities.

That's why service manual tell you which RAM banks have been tested and are homologated with 100% compatibility.

For this series, the base RAM specifications are 4Gb integrated in the motherboard and a single expansion slot for up to 8Gb DDR4 2133Mhz

Dual-channel issues in integrated RAM systems also depend on chipset support.

ed4myra

thanks for your response. I try to understand what you are writing.

First who is Acer Mauers, where can I find this info directly instead of asking people on this forum?

What you are saying is that the motherboard (WL Strongbow_WL) and the Intel chipset limits the high speed bus at 2133.

But the intel i5 chipset in the 56g model supports also ddr4-2400 https://ark.intel.com/content/www/us/en/ark/products/149088/intel-core-i5-8265u-processor-6m-cache-up-to-3-90-ghz.html, so the motherboard is the one that restricts the speed at 2133?

Can you say more about mixing different types of dimms, e.g. is it ok to mix the soldered Micron 2666 4GB chips with a dimm by G.skill ripjaws 8GB 2400 with a lower latency of 13ns?

One more question, the same i5 chipset supports max 64GB memory, excluding video memory, so in dual channel 2x32GB, so why the recommendation of max 8GB in the expansion slot, instead of 32GB?

ed4myra

Today I just came across AIDA64 tool, a 30 day trial version, and this tool gives me a lot of insight:

Right now I have 2 RAM banks; soldered Micron and SK Hynix dimm, both at 2666.
Micron and Hynix are both ram module manufacturers, so different factory sources. 

Aida64 reports that when I benchmark the memory, it runs dual channel at DDR4-2400 speed. 
It also says that 2 memory dimms are allowed, and max capacity per dimm is 32gb, and the mother board memory bus runs effectively at 2400.

So I am a bit confused between Acer Mauer's conservative recommendations vs what a scanning tool like Aida measures in my laptop.

Is it not the bottom line: before you upgrade, test and measure using tools like aida and cpu-z, as even Acer does not commit to it's recommendations, by soldering a 2666 chip, running effectively at 2400.

MaClane

Good afternoon!

There was an error in the translation.
It would be the SERVICE MANUALS containing such information.
They are not made available to end users.

The issue is the instruction set of the processor, chipset, controllers.
Everyone must support a certain frequency.
If only one offers lower support, it will be taken as the basis, no matter what the other frequencies.

When mixing RAM banks with different CASs, frequencies, latencies, and capacities by default, the system will check these drivers factors and limit them to the lowest value.

The point is that on laptops, the support is much lower than desktop motherboards.
Therefore, incompatibility errors occur more easily.

Therefore the ideal is always to use identical RAM banks (capacity, CAS, frequency, etc.)

The fact that only the chipset supports such capabilities is not the defining factor.
The sum of the instruction set and controllers will define which capacity and final value.

ed4myra

thank you sir for your clear answers!

One more I would like to know, Aida tells me that the expansion slot can be filled with a dimm of more than 8GB, at least up till 16GB, maybe 32GB. This is supported by the intel i5 and chipset specs.

What is the reason that Acer recommends max 8GB, as in reality 16GB dimms work with this model?

MaClane

AIDA or any other hardware identification software will only read and interpret physical connections.
That is, physically there is support in the connections and tracks.
But the processor + chipset + controller instruction set limits this value.
These instructions are software profiling not identified by these programs.