Downside to M2 sata drive?

[zod96]

I was thinking of replacing my Samsung 840 PRO with an M2 drive for my Msi Z97 motherboard. i think it would be cool to not have a sata cable or a sata cable and just plug the SSD into the motherboard. But I know their has to be a downside to this. Or is M2 about the same as your regular SSD drive...They must be popular because they are sold out everywhere....but are the M2 drives just as fast as their big brothers just slimmed down...

 

[Aesma]

M2 is brand new, very few choices, very little production, very few systems support it, they're sold out because there isn't that many to begin with.

 

[Abula]

Not all mobo manufacturers implemented the M.2 on a PCIe 4x.

Anandtechs ASRock Z97 Extreme6 Review: Ultra M.2 x4 Tested With XP941

The big feature point of the Z97 Extreme6 is the Ultra M.2 port, offering PCIe 3.0 x4 bandwidth direct from the CPU. This technically suggests a theoretical maximum bandwidth of 32 Gbps / 4 GBps, or 3.938 GBps with the 128/130b encoding afforded by PCIe 3.0. Using regular interpolation of storage overhead, this would mean a peak read/write of 3.2 GBps should the drive be sufficient. ASRock was kind to pass on one of the few native PCIe 3.0 x4 drives in OEM circulation, the Samsung XP941 (read Kristian’s review here). Using this drive we saw a peak read speed on IOmeter of 1.35 GBps, far from the peak that the slot can handle, but it does certainly give plenty of headroom for future devices and earmarks an important development in NGFF devices. The Z97 Extreme6 also has an M.2 x2 slot from the chipset PCIe 2.0 lanes, on which the same drive achieves a 828 MBps peak sequential.

In order to equip the motherboard with an M.2 x4 port, ASRock had two choices. They could combine four lanes from the chipset/PCH into a single slot, although that would severely limit the number of controllers that could be placed on the motherboard without additional PCIe switches. The other method was in the x8/x4/x4 allocation from the CPU, earmarking the final x4 for the M.2. In this method, installing an M.2 drive in this x4 slot would reduce any chipset overhead, but it would also reduce the other PCIe lanes down to x8/x4. This removes any chance of SLI, but Crossfire can still be used in x8/x4. As part of this review, we tested two 7970s at x8/x4 while the XP941 was installed and saw less than a 1% drop in frame rates for our game tests. This is highly important for a few reasons. It means that any motherboard manufacturer should be able to implement this without impacting the frame rates in reviewer benchmarks. It might also drive NVIDIA to remove the x8 lane restriction on SLI so that users can enjoy dual NVIDIA gaming while using an M.2 drive. It also means that Intel needs to step up the number of PCIe lanes on the mainstream CPUs, to at least 20 if not more. This would allow x8/x8 SLI + x4 for M.2, or x8/x4 with two x4 M.2 slots, or any kind of crazy combination therein. Despite the lack of commercial M.2 x4 drives on the market, the fact that ASRock has pursued this whereas the other major motherboard manufacturers did not should land kudos on ASRock’s shoulders.

 

[Wendig0]

I wonder if M.2 drives will suffer in systems where the slot is sandwhiched under the PCI Express slot. I'm thinking exposure to high gpu temps may be a worry to some setups. I could be completely wrong however as M.2/SSD drives are not as prone to overheating as an HDD is.

 

[Tsumi]

The only real downside at the moment is cost and lack of availability, both of which will be changed over time. M.2 promises to be faster than SATA due to direct PCI-E connection.

 

[bigdogchris]

I won't consider M.2 until NVMe is available and I can boot an OS on it. What's the point unless you can install your OS and apps on it?