Memory question

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I have a new quadcore Acer Aspire E 15 that has upgraded itself to  
Win10. I purchased it with 4 GB RAM installed. MS Task Manager says of  
the Memory, Speed: 1333 MHz, Slots used: 1 of 2, Form factor: SODIMM,  
Hardware reserved: 117 MB. I presume 117 MB is reserved for video.

Unfortunately, Acer did not provide a RAM access port. The slots are on  
the MB and the laptop needs total dis-assembly to access the MB.

I use Oracle VirtualBox a lot and with one VM open my total Memory In  
use is like now, 3.1 GB.

Comments and guidance requested. What is the cost of memory? Do the  
benefits of Memory upgrade justify the labor and hassle of total  


Re: Memory question

On 11/4/2015 9:40 PM, Norm X wrote:
Quoted text here. Click to load it

Adding RAM doesn't look like it's too difficult if you take your time. I  
was nervous the first few times I opened up laptops, I was careful to  
make a drawing so I knew where each screw went... buying the right  
screwdriver set is recommended, if you decide to u/g.

Re: Memory question

Norm X wrote:

Quoted text here. Click to load it

First check the specification of the computer.  Even if there were an
empty memory slot, you cannot use it if you already maxed out the total
memory capacity of the mobo.  I've even seen where the mobo had the
foils to solder a memory connector but there wasn't a connector there.
Check what the specs say is max memory for that model.  You might
already be at the max.

You said "Acer Aspire E 15".  That does not specify which model.  Their web page shows 4
models.  Clicking on the More link shows 18 models.  One of the models
lists 12 GB for memory; however, that does not mean all their models can
take that much RAM (no connector, not enough address lines).  Their
cheapest model ( )
says: standard memory = 4 GB, maximum memory = 8 GB.  So you likely can
go up to 8 GB on whatever model you have.

That shows disassembly to replace the HDD and RAM.  After taking out the
umpteen screws from the backplate, you have to pry apart the tangs
holding the keyboard from the backplate.  Be careful.  The video shows
the HDD is easy to get at (once you get the keyboard out of the way):
timemark 1:30.  Everything after timemark 1:47 to 2:25 is getting at the
memory.  Note the video is sped up quite a bit at places.  

Note that is only *ONE* memory slot.  You'll have to replace your old
SO-DIMM memory module with a new and bigger one.  Then you'll have to
figure out what to do with the old one.  Someone on Craigslist or Ebay
might want it.

Make sure you put in the right type of memory.  The guy in the video had
PC3L (lower voltage), not PC3.  There are online memory vendors that
provide a lookup service, like:

Don't try to search on "Aspire E 15".  Search on "Aspire <model>".  If
your model is ES1-512-25TP then search on "Aspire ES1-512-25TP".
Crucial lists a PC3 module for that particular Aspire model.  I don't
know what model you have but then you can get that info and do your own
online lookup.

Re: Memory question

Norm X wrote:
Quoted text here. Click to load it

On some of these things, you can use the processor entry to determine
the max RAM. Looks like it is 8GB total. Some Amazon advert said
this was the processor in the machine.

Some general rules of thumb:

1) Under memory pressure, the OS can use as little as around 350MB.
2) When "fully inflated" the OS likes 1GB of RAM, on a small system.
3) Having 1GB for OS, and 1GB for applications, is a nice minimal
    size for a system. Such a choice means "less swapping". Tablets
    are sold with 1GB total RAM (and cannot be expanded) and for those,
    they're always under memory pressure. A 2GB sized system is a
    good place to start.
4) Once you've supplied 2GB for the host OS, you can use
    2GB for a guest OS. That would include Win7/Win8/Win10.
    So one guest OS will be very very happy in your existing setup.
5) You could use a RAM expansion if planning on simulating a
    bunch of computers. I do that occasionally, but not as much
    as I used to. For example, I simulated video streaming
    between two VMs, just so I wouldn't have to set up physical
    computers to do it. The most VMs I've had running at one
    time is three of them, and one was operating with a trimmed
    supply of RAM.

And I can also comment on how much is too much RAM. The test
machine has 64GB, which cost $800. I probably should have
stuck with the original 16GB setup, which cost $200. I have
used all of the RAM, while running Microsoft ICE, and it
took an entire week of computing (and some tricks), to keep
that program running. I ended up using a 128GB pagefile,
to "encourage" it to finish. This is the longest I've
ever waited for any program to finish. Having a lot of
RAM, tends to encourage you to attempt un-scalable projects.

If you run 64GB of memory, the OS will swell up and use
6GB for itself (it doesn't stop at 1GB, as in (2) above).
If a program uses mapfiletoRAM, the program will use 5-10GB
before enough is enough (it's not clear whether that was an
address space limit or something else). And loading and
unloading mounds of RAM, is not that fast. While memtest86+
benches the RAM at 17GB/sec, the typical load and unload
rates are just 1GB/sec in Windows. That means it takes a
minute to "swell up" when running Microsoft ICE. So large
amounts of RAM aren't all that scalable. The processor in
my machine, just wasn't meant to run that amount of RAM
in a sprightly fashion. Between 8GB and 16GB
is the sweet spot, apparently.

So if I was limited to 8GB, I think I'd be quite happy.
(I have 8GB on the machine I'm typing this on :-) )
I would no longer be waiting for a minute, for some
runaway program to "hit the top of RAM" like on the
other machine that has the 64GB.

The price of RAM must have come down, as this
module is dirt cheap. 4GB for $22. DDR3L type (1.35V).
So the disassembly time would be the most obnoxious
part of the whole project (lots of tiny screws,
some with custom length so don't put them in the
wrong holes and so on).

You can use CPUZ to attempt to read the SPD on the
existing SODIMM, and try and match it. This is the
ZIP version (might be portable, not sure).

I can't find the Acer Aspire E15 on or
on, so I cannot verify the memory
choice there. I'd probably want to match the
CAS timing number just for fun. The SPD should have
several timing tables, and the current operating speed
(likely DDR3L-1333 or 667MHz) should tell you which timing
table to use. CPUZ would likely use the 667MHz in its
displayed information.

Expect the battery life to be slightly shorter
when the second SODIMM is installed. I suspect the
second SODIMM slot is on the second channel of the
dual channel RAM interface. So when that channel
is powered up, there'll be a bit more power usage
(a couple watts at most).

The RAM chips are large enough now, that a 4GB
DIMM can be constructed with just eight chips.
So the SODIMM shouldn't be too squeezed for space.

Happy disassembling,

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