# Question about Ultra M.2 slot on ASRock X370 Killer SLI/ac



## Flogger23m (Jul 10, 2018)

Looking to pick up an M.2 SSD soon. Looking at a Crucial MX500 1TB; would consider NVMe but those seem to be notably more expensive so I may just get the SATA drive.

My motherboard has two M.2 slots, one of which is an "Ultra M.2". Specs for my motherboard are here:
ASROCK X370 Killer SLI/ac

Is there anything different about "Ultra M.2" slots when it comes to SATA drives? Or can I safely clone my current SATA 3 form factor SSD to a new M.2 SATA and then boot from the Ultra M.2 slot?

Is there anything else BIOS wise that may need to be done if I boot from the M.2 slot, or will it detect the drive like it does for a traditional SATA form factor drive?


Mainly doing this from a cable management perspective so I can use three HDDs if needed, and plan on moving one of my old SATA form factor SSDs to my laptop.


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## commission3r (Jul 10, 2018)

means it will accept nvme or sata


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## Athlonite (Jul 11, 2018)

By using the Ultra M.2 slot you'll get the fastest speeds but the other slot is an M.2 SATA slot by using it you'll get SATA III speeds and no more and you'll loose the use of 1 or more SATA ports otherwise for all intents and purposes there's no difference between using NVME or SATA M.2 SSD's they'll act the same as a standard SATA SSD plugged into your SATA ports


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## newtekie1 (Jul 11, 2018)

commission3r said:


> means it will accept nvme or sata





Athlonite said:


> By using the Ultra M.2 slot you'll get the fastest speeds but the other slot is an M.2 SATA slot by using it you'll get SATA III speeds and no more and you'll loose the use of 1 or more SATA ports otherwise for all intents and purposes there's no difference between using NVME or SATA M.2 SSD's they'll act the same as a standard SATA SSD plugged into your SATA ports



No, that isn't how it works.  Both slots are capable of NVMe(PCI-E) or AHCI(SATA).  The difference is the Ultra M.2 provides a PCI-E x4 3.0 link, the other M.2 only provides PCI-E x2 2.0.  But both slots provide a normal SATAIII connection, when a SATAIII based M.2 SSD is inserted in either of the slots, one of the normal SATA ports will be disabled.  If a PCI-E based M.2 drive is inserted, no SATA port will be disabled.

If you are using a SATA based M.2 SSD, there will be no speed difference between either slot.  There will only be a speed difference if you use a PCI-E based SSD.


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## Flogger23m (Jul 11, 2018)

newtekie1 said:


> No, that isn't how it works.  Both slots are capable of NVMe(PCI-E) or AHCI(SATA).  The difference is the Ultra M.2 provides a PCI-E x4 3.0 link, the other M.2 only provides PCI-E x2 2.0.  But both slots provide a normal SATAIII connection, when a SATAIII based M.2 SSD is inserted in either of the slots, one of the normal SATA ports will be disabled.  If a PCI-E based M.2 drive is inserted, no SATA port will be disabled.
> 
> If you are using a SATA based M.2 SSD, there will be no speed difference between either slot.  There will only be a speed difference if you use a PCI-E based SSD.



Is there anyway to tell which SATA port will be disabled? I assume there would be and will have to double check the manual.


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## IceShroom (Jul 11, 2018)

Flogger23m said:


> Is there anyway to tell which SATA port will be disabled? I assume there would be and will have to double check the manual.


M.2 Ultra is directly connected to CPU, so installing any drive on that slot will not disible any sata port. Don't know about the other M.2 slot though.


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## Flogger23m (Jul 11, 2018)

Thanks for the replies. Decided to just get a regular SATA form factor after reading about possible throttling on some of these M.2 drives. I do have good cooling so I doubt it would have been an issue, but I saved $15 and the chances of thermal throttling are practically zero now. 

I suppose my next SSD will be an NVMe, but that will likely be some years down the road as I will now have 2TB of SSDs for my desktop! Before anyone asks why I need so much space, my 750GB drive is almost full after installing 7 or so games on it...


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