Intro Vendor: Transcend Equipment: MTS400 M.2 256 GB Price: (On test date) £92.57 or 114.45$ Even though that I am satisfied with my 1st gen EliteBook 850 from HP it has always bothered me that the SSD that came with the 850 is only 128 GB. I am attending school as Data Technician, were we quite often are handling Virtual Machines, and as you can imagine; 128 GB with an OS installed, with project files etc. there isn’t much room for many Virtual hard drives. Luckily the 1st gen 850’ies have a slot for a m.2 SSD, but it is limited in length to 42mm. I began to scout the internet, and I quickly found the Transcend MTS series M.2 SSD. The MTS series from Transcend come in 4 different flavours - Picture borrowed from their website: As you can see the largest difference between the four of them are the physical characteristics of the m.2’s. And that the MTS800 can be acquired with up to 1TB in capacity. As mentioned the my EliteBook only has room for a 42mm m.2 so the MTS400 is the one I bought with 256 GB capacity, this to me was the perfect balance between cost and capacity based on what I am going to use the m.2 for, namely small Virtual Machines lab when I am at school. 256GB should be enough for four windows server VM, a router VM and a Windows or Linux client. The MTS400 is based on the MLC NAND flash technology MLC is an acronym for Multi Level Cell this means that the cell can store multiple bits, this is very good news for production costs, but unfortunately it has its drawbacks as the cell deteriorates faster than for example eMLC (enterprise Multi Level Cell) and SLC (Single Level Cell), but is more durable that TLC (Tripple Level Cell). The MLC NAND flash cell has a read/write life cycle expectancy around 10’000. This doesn’t concern me that much though, it should be able to handle over 2PB of read/write cycles (this is theoretically though, my guess is that the first failures will occur at around 1PB, I haven’t done a read/write test of that magnitude, as It would render the m.2 useless). Testing Testmachine: HP EliteBook850 G1 CPU: Intel® Core™ i5-4300U RAM: 2 x Kingston KCP3L16SD8/8 1600mhz Main Storage: Micron RealSSD C400 2,5” 128GB The first thing I tested was to copy two 10 GB dummy files from the M.2 to the SSD in my laptop. As you can see on the left read performance on the M.2 quite exceeds the write performance on the SSD as was to be expected: The M.2 isn’t even sweating. The next thing was to reverse the test; I copied the same two 10 GB dummy files back to the M.2 Here the M.2 is working quite hard to keep up with the input from the SSD, again it was to be expected. But it is interesting to see that the M.2 write is maxing the SSD’s write speed, but the SSD can’t quite max the M.2 write speed (albeit marginally). Next I wanted to see how the M.2 handles small files. I created 10240 1MB dummy files, as above I started with the read speed. Again, we see that the M.2 isn’t under large stress, but the transfer rate is quite slower, than with the large files Now to the write, I copied the lot back to the M.2: A whopping 220MB/sec slower that with the large files. I didn't just want to take Windows words for the result so I tried AS SSD Benchmark tool. The AS SSD Benchmark tool has several tools build in., The main tool measures read/write speeds and access time: The second tool benchmarks the copy performance of the M.2: This is about what I expected from the numbers we have seen in the previous test. The third tool I found quite interesting as this measures compression read and write speeds: As we can see there are no significant drops in speeds when handling compressed data. Conclusion The Transcend MTS400 256GB is not a blazing fast M.2 SSD, especially with smaller files, nor is it the most durable given it is MLC structure. But the MTS400 is not aspiring to take the first price in either durability or speed. However, the price tag speaks for itself it is cheap and it works, it is as simple as that.