I recently discovered that my Laptop has a second slot. The info I had when I bought it was that it had just one. My model number has a few configurations, and I kept seeing that models had a max of 16GB with 2 x8. HP engineer had it apart the other day, and when I asked hi to check, he whipped out the single 8GB and confirmed it has 2 slots and a maximum of 16GB (I've noticed slot info is also shown in task Manager now (not sure if it used to)).
 
I was taught not to just handle RAM unless you are earthed. I had corrupted new RAM on my old EMU 6400 when I upgraded. Even though I thought I was earthed (earth strap) I couldn't be sure if I corrupted the RAM, or if it came that way.
 
They way the HP Engineer handled it, was no surprise. Even when you buy ram here, someone just after you pay will whip it out the packaging and stick a sticker direct onto a chip, with no concern over static.
 
So I'm thinking, maybe I should get a matched pair, from overseas (to avoid shop staff handling), then move this current 8 to my work laptop,
 
Is there a benefit to both RAM chips being the same type? Do I need to think about matched pair. or should I just get another 8, chuck it in and stop overthinking. I can't earth myself anyway, they don't seem to have anything connected to earth.

You should always install memory in "pairs" - same brand/type for best performance.  With only one memory module its not running "dual channel" which is needed for best performance (two 4GB RAM modules is better than one 8GB).
 
Before you just randomly order memory, you must get compatible memory that includes the type and speed.
Also avoid the Kingston Value Ram (VR) as it is crap and almost always saw problems with the Value Ram on the Dell forums.  The higher priced Kingston is OK.  
 
You can check what is needed on the Crucial Memory site (what we always advised on the Dell forum for non-Dell as it was guaranteed to work in a Dell, and probably the same applies to a HP).
www.crucial.com

My specific model doesn't seem listed on Crucial, but it was their ram I was thinking of.
I had seen this on amazon
https://www.amazon.co.uk/Crucial-PC3-12800-SODIMM-204-Pin-Memory/dp/B008PSEHAS/ref=pd_sbs_147_2?_encoding=UTF8&psc=1&refRID=GXY4KDJ6PMWSW6R9RH2X
 
SSDs seem about the same price here, so I I think I'd do that at the same time.
My father is visiting in January, so I think I'll get him to bring some RAM

Just ran their system scanner. Which seems to say 8gb is the max, or am I reading that wrong
http://www.crucial.com/us...nview/04FE733F31D926C3

I found an 8 GB memory module, that is the same as the part number listed in the HP manual for your model.
That would be cheaper than buying new memory.  It would give you the same part number so it would be a "pair"
http://www.impactcomputers.com/693374-005.html

Thanks for doing that. I'm just looking to see if that's available in the UK.
 
Where did you get that part number from, or is it just HP's RAM of the same spec?
 
 
 
 

Your HP - Compaq ENVY 15 (4th Gen Intel Core)

system specs as shipped

memory

*Not to exceed manufacturer supported memory.
8GB
 
This is from the scan, is it say 8gb is my systems ram, or that 8gb is the maximum supported memory
http://www.crucial.com/us...nview/04FE733F31D926C3
 

Kamikaze

Your HP - Compaq ENVY 15 (4th Gen Intel Core)

system specs as shipped

memory

*Not to exceed manufacturer supported memory.
8GB

This is from the scan, is it say 8gb is my systems ram, or that 8gb is the maximum supported memory
http://www.crucial.com/us...nview/04FE733F31D926C3

That scan says "system specs as shipped".  8GB.
 
The max manufacturer supported memory would involve two things:
1. Number of physical RAM slots.  Check!  You found two...
2. Is the BIOS capable of handling additional RAM?  Probably, but to be sure check with HP support, or post on their forum.
 
I agree with Firebird's advice on the RAM matching.  I have also found that if you mix two different speeds of RAM, the whole memory bus will run at the slowest latency and frequency of the module with lowest common spec.

Yeah I think buying a pair, and moving the existing 8 to my single slotted work laptop (which supports up to 8, but has 2) will be the best option. Seems less messy with getting the pairing right.

Wow, I cannot see the actual specifications for this machine. Set on a loop of inputing the product number G0T59AV, Selecting how to see how much ram I can add, which says deduct what's installed from the specified max, which I find by entering my product number and starting the loop again.
 
http://support.hp.com/us-en/product/HP-ENVY-15-k100-Notebook-PC/7234894/model/7415731/manuals
 
this pdf is linked and says 16 is the max
http://h10032.www1.hp.com/ctg/Manual/c04434142
 
but refers to the range in general and doesn't confirm my machine.
 
I'm going to guess it's 16 as there are 2 slots and a factory 8 in the first
 
Memory
Two SODIMM slots
DDR3L-1600 MHz Dual Channel Support
Supports up to 16 GB of system RAM in the following configurati
ons:

●
4096 MB total system memory (4096×1)
●
8192 MB total system memory (4096×2)
●
8192 MB total system memory (8192×1)
●
12288 MB total system memory (8192×1 + 4096×1)
●
16384 MB total system memory (8192×2