@jase2985 , thank you so much, I really appreciate your help, I've learnt a lot this evening.

So the specs mention capacities of 128 and 256GB only. Is there any reason I shouldn't look at something larger?

i have too :)

kiwifidget:

 

So the specs mention capacities of 128 and 256GB only. Is there any reason I shouldn't look at something larger?

 

im guessing when the laptop was made that was the common sizes for SSD's

I was wondering that myself. I do notice the Crucial upgrades page does have a 1TB module on it, so I'll take that as a sign. :)

The Kingston site I linked above shows up to 2Tb drives as compatible.  That site has *never* let me down and I use it most months for the last 10 years.

@dynamic Thanks for your links, some really good stuff there too.

FYI I ended up getting one of these...

ADATA SU800 1TB M.2 2280 SATA 3D NAND

 

I was hoping to see some improvement in the performance of my OS/SSD, but I cant say I've noticed any. The laptop takes considerably longer longer to boot up than it used to, maybe thats more the fault of Windows10 than the hardware.

 

However it is nice to have some extra storage without the pain of replacing the OS/SSD. :)

download crystaldiskmark and check what speeds your getting

but im guessing you didnt put your OS onto the new drive?

does it take longer at the bios part or the loading windows part?

SSDs are all so fast now that one is basically as fast as another, in practice. If a slightly faster SSD doesn't help your workload (booting Windows) then the bottleneck is elsewhere - CPU, I/O, etc. Given it takes about 15 seconds and probably only happens once a day or so, at most, probably not a big deal.

When the laptop was new (3yrs ago), startup was very quick, and it stayed quick for a long time. The last couple of months there has been a marked slowing down of a number of processes. I presumed this was due to a lack of disk space on the OS-SSD (Crucial CT250MX200SSD1), it was down to 10GB free. 

I had hoped offloading some data onto the M2-SSD would improve things but if it has it's not noticeable. My comment before was more observational than bitter disappointment. 

I did the crystaldiskmark tests and the OS-SSD and the new M2-SSD are much the same for performance. So I think I made the right choice putting the M2 as the secondary drive, and not going through the hassle of making it the boot-Windows10 drive, or just replacing the original SSD with a biggerer one.

I am super happy just to have more storage capacity. Better performance would have been a bonus.

Thanks everyone for your help and being awesome Geekzoners.

For slowness problems you need to check for what is running and you should be checking for 'bad stuff'. It won't be a win 10 problem per se. 

For starters, have you run task manager and clicked the Start-up tab? In my case I have 18 progs listed but 11 are disabled i.e. stopped from starting at boot time.

This is probably not the cause of your laptop being slow to boot. I tell this story to show how unexpected things can affect the boot time. My laptop runs Win 7 Home premium with a Samsung SSD 850 500 Gb and is pretty snappy on the boot up. About a year ago it started being extraordinarily slow booting up so much so I would hit the start button and make a cup of tea.

I looked for many causes including using Task Manager to stop unwanted processes from starting automatically. I can't recall what made me figure out the problem, but it was my optical drive that was faulty. The BIOS had the boot sequence looking for the Windows boot files on the optical drive before looking on the SSD. Since the drive was faulty the boot process would sit waiting for the drive to respond before finally timing out and proceeding to the SSD. A new optical drive solved the problem.

@linw Thank you, I will look into the startups.

@technofreak Thanks for the tip, but my laptop has no optical drive.