[SOLVED] Laptop RAM upgrade – which frequency and latency to choose?

estriden

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Jul 3, 2018
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I would like to upgrade the RAM on my Acer Aspire A515-51G and I'm not quite sure what to pick. First of all, here is a screenshot from HWiNFO:

aQ8HqZf.png


Note that even though I have 8GB of RAM, HWiNFO is only showing one module with a capacity of 4GB. And when I open the back of my laptop, indeed I can only see one RAM slot which contains a module with "4GB" printed on it. So I assume the remaining 4GB are directly integrated in the motherboard?

As for the replacement, I would like to replace the removable 4GB with a single 16GB module instead (giving me a total RAM capacity of 20GB) and I see many different SO-DIMM modules of that size. Do the specs have to be exact matches to my existing RAM, i.e. do I have to choose something that says "DDR4-2400, CL17-17-17", or could a model with higher frequency and/or lower latency give me better performance?

For instance, Crucial's CT16G4SFRA266 (DDR4-2666, CL19-19-19) is actually slightly cheaper than the CT16G4SFD824A (DDR4-2400, CL17-17-17), while the CT16G4SFRA32A (DDR4-3200, CL22-22-22) is only a bit more expensive. So I would of course buy the first or the third one if it would be better for me.

And more generally speaking, should I prioritize frequency or latency when picking a new model? E.g., how do I know if a DDR4-2400, CL16-16-16-39 or a DDR4-2133, CL15-15-15-36 will give me better performance?
 
Solution
what would you do with that much ram? a dual channel with the same capacity is better than flex mode. Check for the laptop max ram upgrade, check for the laptop max ram speed so you wont over spend. 2x8gbs is better than 4+16 performance wise. aim for your laptop memory max speed and aim for the lowest CL if you could.

Lower timing = faster cycle and faster access.

Your laptop wont benefit from faster ram and lower latency since it's not designed to take advantage from it, unless you're on a ryzen, 3200mhz and dual channel is a must for optimal performance.
what would you do with that much ram? a dual channel with the same capacity is better than flex mode. Check for the laptop max ram upgrade, check for the laptop max ram speed so you wont over spend. 2x8gbs is better than 4+16 performance wise. aim for your laptop memory max speed and aim for the lowest CL if you could.

Lower timing = faster cycle and faster access.

Your laptop wont benefit from faster ram and lower latency since it's not designed to take advantage from it, unless you're on a ryzen, 3200mhz and dual channel is a must for optimal performance.
 
Solution

estriden

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Jul 3, 2018
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what would you do with that much ram? a dual channel with the same capacity is better than flex mode.

So as mentioned, I suspect that half of my current 8GB of RAM are built into the motherboard and are non-removable, because I only see one 4GB module when opening up my laptop. You can see the insides of my laptop in this video. So dual channel with same capacity won't work since the 4GB half is fixed. (But I'm not 100% sure about that, since this built-in 4GB does not show up on any inspection tool like HWiNFO, cpu-z or Speccy. They all just show one slot occupied with a 4GB A-DATA AM1P24HC4R1-BUNS. And since it doesn't show up anywhere, I can only assume that it has the same frequency and latency as the removable stick.)

And yes, 20GB is maybe be a bit of an overshoot, but I feel that 12GB (4+8) might be a too meagre upgrade for me and my RAM would probably reach its limits again very soon.

Any idea how to find out the max speed my laptop supports? HWiNFO says under the Memory section "Maximum Supported Memory Clock: 1200.0 MHz", so I guess that would be DDR4-2400. Is that it?
 

estriden

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Jul 3, 2018
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If you want to take off all the motherboard and inspect the ram slot you could see wether the ram is soldered or just in the otherside of the motherboard

For me, opening up the back of my laptop is daring enough :sweatsmile:
[Edit: Back of the motherboard looks like this, no second RAM stick visible. So it's probably soldered?]

But since the removable stick is DDR4-2400, CL17, surely any RAM with those specs I'm putting in instead should also work, right? Or is there something else to look out for?
 
Last edited:
I like your idea of just changing the module you have access to. But the problem with DDR4 is that is doesn't play as well with other modules as previous technologies so just be sure you have a solid return policy from a reputable company--for whatever you do decide to try.
 

estriden

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Jul 3, 2018
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But the problem with DDR4 is that is doesn't play as well with other modules as previous technologies so just be sure you have a solid return policy from a reputable company--for whatever you do decide to try.

Thank you, I'll make sure to do that.

Once installed, how do I properly test the new RAM for compatibility? Just use it for a week or so and see if any unusual crashes etc. happen?
 
Thank you, I'll make sure to do that.

Once installed, how do I properly test the new RAM for compatibility? Just use it for a week or so and see if any unusual crashes etc. happen?
The best test is to download the ultimate boot cd and use memtest. There's several different versions of memtest, but 4/5 is what I usually use. Just set it to go and you won't be able to use your computer until it's done since it boots to dos to run. And it takes hours so just run it overnight. You shouldn't have a single error else it failed. Version 5 would sometimes give me errors that version 4 would not, so I tended to use version 4.
 
I would like to upgrade the RAM on my Acer Aspire A515-51G and I'm not quite sure what to pick. First of all, here is a screenshot from HWiNFO:

aQ8HqZf.png


Note that even though I have 8GB of RAM, HWiNFO is only showing one module with a capacity of 4GB. And when I open the back of my laptop, indeed I can only see one RAM slot which contains a module with "4GB" printed on it. So I assume the remaining 4GB are directly integrated in the motherboard?

As for the replacement, I would like to replace the removable 4GB with a single 16GB module instead (giving me a total RAM capacity of 20GB) and I see many different SO-DIMM modules of that size. Do the specs have to be exact matches to my existing RAM, i.e. do I have to choose something that says "DDR4-2400, CL17-17-17", or could a model with higher frequency and/or lower latency give me better performance?

For instance, Crucial's CT16G4SFRA266 (DDR4-2666, CL19-19-19) is actually slightly cheaper than the CT16G4SFD824A (DDR4-2400, CL17-17-17), while the CT16G4SFRA32A (DDR4-3200, CL22-22-22) is only a bit more expensive. So I would of course buy the first or the third one if it would be better for me.

And more generally speaking, should I prioritize frequency or latency when picking a new model? E.g., how do I know if a DDR4-2400, CL16-16-16-39 or a DDR4-2133, CL15-15-15-36 will give me better performance?
Remove the stick of ram and see if it will boot.
If it does open task manager/performance/memory.
If it shows 2400 speed here's what crucial recco's.
https://www.amazon.com/dp/B019FRBHZ...0e71-4ef3-8b35-b7d39041626b&tag=microncsus-20