M.2 SATA/SSD Question

Hi everyone

I'm considering getting the Lenovo Thinkpad E550 and I've been reading some reviews. One of the 'cons' of the laptop was that it's missing an M.2 SATA slot.

Question 1:

After doing some research, I know this something to do with the SSD, but I'm still not really sure what this means and why it is a disadvantage? Could someone please explain!

Question 2 (related):

The SSD the laptop comes with is the following: 128GB Solid State Drive, SATA III. Is this a good SSD and what does the SATA III mean?

Sorry if these are really stupid questions!

Thanks

 

From my understanding, the M.2 slots allow for a greater bandwidth than the 2.5" sata (particularly the PCIe M.2 slots).

This is only significant if your SSD is saturating the available bandwidth. SATA 3 allows for 6Gb/s (or 768MB/s). So if the max speeds of your SSD is not greater than 768MB/s I don't believe there is significant advantage for going with M.2.

 

SATA is the standard connector for a HDD or SSD. SATA III is the newest version that has a max speed of 6 Gbps. M.2 is a form factor that looks like this:



It has the advantage of not using one of your hard drive bays. M.2 can connect via SATA or PCI-E (used for graphics cards and other expansion cards). An M.2 SATA port only has the advantage of saving you rack space, but an M.2 SSD using PCI-E will be capable of a max theoretical speed of 10 Gbps compared to the 6 Gbps limitation of SATA III.

I hope that clears things up.

 

The M.2 drives available currently and the foreseeable future are not worth considering when price/performance vs. 2.5" SSD drives are concerned. Also note that the benefits of an M.2 drive depends not only on the drive itself (native PCIe 3.0 x4 enabled), but also on the connector on the systems M/B. Most/many right now are mSATA equivalents and not worth the premium at all - not to mention M.2 drives actually perform worse vs. their 2.5" counterparts on certain workloads and worse; heat/throttling issues.

Having an M.2 connector is a bonus. But right now it is only a potential bonus. If/when M.2 drives arrive worth buying... you'll read about it right here at NBR.

Note: I have used a Broadwell based system with an M.2 SSD and it is noticeable snappier in 'light' loads. But trading real performance for snap is always a bad idea - wait when both are better than the current 'standard': 2.5" ~500GB SSD's or larger...

Hope this helps.

 

Another thing to consider for current (June 2015) Lenovo systems: the ones with M.2 slots are limited to 42mm M.2 drives, which limits the capacity to 256GB max. Standard 2.5 inch SSDs are offered in capacities up to a terabyte and current controllers are typically designed to only get full performance from higher-capacity drives (typically 480GB or more), so you can upgrade the current drive in your system with a higher-capacity and faster one.