Creating partition on existing drive


Standard Member
My gaming PC currently has the following drives:

C: 128GB SATA SSD OS drive with Windows 10 and programs.
Currently only has about 20GB free and I think the drive is failing.

G: 750GB SATA SSD drive, mainly for XBOX Game Pass games, EA Games, Oculus Games.
Has about 150GB free.

S: 1TB NVME M.2 drive, for Steam library.
Has about 350GB free.

What I would like to do is move my OS from the failing 128GB drive to the NVME M.2 drive, but without having to delete / uninstall all the games stored there.
Is it possible to create a new partition on the NVME drive, say 200GB, and move the OS over to it?
I can then remove the failing 128GB drive.

Is this possible? If so can someone layout the process for me?

The NVME drive came with a copy of Acronis software, which I believe can be used for this purpose.

Any help much appreciated!


Active Member
I would move all of your data off the NVMe drive and clone your 128gig SSD to the NVMe drive and then move all of your data back.

You will keep your OS install and everything as is.

I don't think you can partition your NVME drive and clone the OS install to that partition. Far easier just move stuff around and then move it back when youre done.

Where do you stay? Maybe if you needed a drive for a week just to move data around, someone could lend you it.

I would offer but I doubt you live in Belfast. Let me know.


Standard Member
OK, I think what I'm going to do instead is copy everything off the NVME drive (I have a couple of external drives I can copy stuff over to), and then format it so it's clean, then I'll clone the 128GB OS drive over to it, with no partitions on the NVME, just the full drive. Then once everything is up and running I'll copy my steam library back onto the NVME.
The NVME is directly slotted into the mobo by the way, not on a PCIE adaptor card.
A few questions:
1. Concerning drive letters, if my 128gb OS drive is currently 'C', when I clone it over to the NVME will that also become drive 'C' or will I need to choose another letter? (I'll be taking the 128GB drive out of the PC completely once it's cloned over).
2. If I need to choose another letter will this cause problems with files etc looking for 'C' when it doesn't exist anymore?
3. Can I change the NVME to 'C' afterwards once the original 'C' drive is gone?
4. Do I need to do anything in the BIOS to make the PC see the NVME as the OS drive?

Sorry for all the questions but this process is new to me and I don't want to mess up and make the PC unusable!



Active Member
I'll clone the 128GB OS drive over to it, with no partitions on the NVME, just the full drive. Then once everything is up and running I'll copy my steam library back onto the NVME.
If you do that the steam data will be on the C drive and none of your game paths will work. when you clone your c: drive to your M.2 don't use the whole 1TB space just clone it a partition with the additional size you want then leave the rest unallocated.

You will need to go into UEFI and tell direct your your boot to your M.2 drive, or you will get a boot failure. If you select windows boot manager boot option, it will automatically select the correct boot partition and will automatically designate this C:

Once you are happy it boots you can then create a new partitioin for the steam stuff and assign it the same drive letter it had previously in windows disk manager. then copy your steam stuff back to this partition.


Standard Member
Thanks Jimscreechy, that makes sense about the game paths.
So, once the cloning is done, I remove the old 'C' SSD from my case, then when I turn the PC on I go into my BIOS and select 'windows boot manager option' and it'll automatically find the NVME to boot from?
And once I'm in windows, I can then partition the NVME and call the new partition 'S' and copy my steam stuff there?


Well-known Member
Personally, I wouldn't consder partioning any drives - why compromise storage space with partitions?

Just buy a 500Gb 1Tb SSD for sole use of your steam library. They are really cheap at the moment.

Clone your steam games to the new SSD

Clone your C drive to the existing NVME drive.

Re-assign paths for the games and done. Then you have no restrictions on your OS/prgram file storage space and your games library's are not on the same drive as the OS, which can cause bottlenecks.
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Distinguished Member
Can you have more than one m2 drive on your motherboard. If you can just buy a 512gb one and clone the OS one.


Standard Member
That's another option I guess Chuckmountain. My motherboard is an Asus Z370-H gaming, it has 2 M.2 slots, but I heard there's a limit on PCIE lanes or something that I don't understand.
I already have the 1TB Sabrent NVME M.2 SSD in one. Will putting in another limit speeds on something, like the GPU (it's a 3080)?


Active Member
Ok so there is a lot of information on PCIE lanes and the bandwidth available, and specifically it depends on which slots on your motherboard are occupied that determines how the lanes are split for your GPU running in 16 or 8 lane mode.

I can't speak to your specific motherboard but generally if slot 1 and 2 are occupied it runs in 8 +8 and if only one slot then it runs in 16 mode. The first m.2 has 4 dedicated lanes to the CPU and isn't affected by your 8x2 or 1x16 config. Normally the second M.2 is run via the chipset so this maybe a bottleneck depending on transfer rates but I HIGHLY suspect it wont in your case.

Additonally (according to what I have read) most cards including your rtx3080 function pretty much the same on 16 or 8 lanes . Again there is a lot of info on this is you want to dig a little.

Normally the chipsset controlls the second m.2 which is why you will see something like 'when m.2.2 is occupied sata 5&6 are disabled. since resouces available won't support both.

Personally, I agree with the other posts and would run 2x m.2 in both slots and in fact this is how my system runs. The answer here is (thouygh you need to
check your board details specifically) it is dependant on which PCIE slots are occupied rather than if you have 2 x m.2 drives.

Hope this helps
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Standard Member
OK, new plan: I'll leave my existing 1TB NVME 'S' drive and 750GB SSD 'G' drives alone, and I'll get a new probably 500GB NVME to put in the other M.2 slot, and clone the OS 'C' drive over to it as suggested.
Below is a pic from my mobo manual which I've marked up to show what is connected where at the moment.

Regarding what I already have connected (and assuming the 128GB SSD in SATA6G_1 will be removed) is this likely to work?

Thanks for all the help!


Active Member
The short answer is yes. I'm assuming that your not using PCIE-2 or PCIE-3 in which case your PCIE-1 SLOT labelled PCIEX16X8_1 will run with 16 lanes.

The top M.2 is the CPU direct one labelled M.2_2 and the bottom one M.2_1 is actually the chipset one and FYI this chipset also handles data from other nodes such as USB and SATA. I've no idea why they label it like this since it seems backwards to me but hey, go figure. At any rate installing a second will not affect the bandwidth to your GPU so you can relax.. not that I imagine you'd ever be able to tell even if it was running at x8.

I would personally install the system M.2 (C:\) in the top since you really want your rig accessing system files as fast as possible, this drive is always in use whilst your Steam drive is only being used when your gaming... but to be honest I don't think it really makes too much difference unless your putting a serious workload on your chipset. Anyway either can be assigned any letter, so no biggie.

To be honest this isn't a difficult upgrade to do, backing up stuff is probably the most important step - just in case, but strictly speaking if you follow the plan it should go smoothly

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