The Samsung SSD 850 EVO mSATA/M.2 Review

AnandTech Storage Bench - Heavy

While The Destroyer focuses on sustained and worst-case performance by hammering the drive with nearly 1TB worth of writes, the Heavy trace provides a more typical enthusiast and power user workload. By writing less to the drive, the Heavy trace doesn't drive the SSD into steady-state and thus the trace gives us a good idea of peak performance combined with some basic garbage collection routines.

The Heavy trace drops virtualization from the equation and goes a bit lighter on photo editing and gaming, making it more relevant to the majority of end-users.

The Heavy trace is actually more write-centric than The Destroyer is. A part of that is explained by the lack of virtualization because operating systems tend to be read-intensive, be that a local or virtual system. The total number of IOs is less than 10% of The Destroyer's IOs, so the Heavy trace is much easier for the drive and doesn't even overwrite the drive once.

The Heavy trace has more focus on 16KB and 32KB IO sizes, but more than half of the IOs are still either 4KB or 128KB. About 43% of the IOs are sequential with the rest being slightly more full random than pseudo-random.

In terms of queue depths the Heavy trace is even more focused on very low queue depths with three fourths happening at queue depth of one or two. 

I'm reporting the same performance metrics as in The Destroyer benchmark, but I'm running the drive in both empty and full states. Some manufacturers tend to focus intensively on peak performance on an empty drive, but in reality the drive will always contain some data. Testing the drive in full state gives us valuable information whether the drive loses performance once it's filled with data.

In the Heavy trace the 850 EVO scores highly. As I've said before, it seems that only Samsung has found the secret recipe to boost performance under SATA 6Gbps because no other manufacturer comes close to it in this benchmark. 

Moving on to latency and the 850 EVO still keeps its lead compared to other manufacturers' drives. The difference is nowhere near as significant as in the throughput metric above, but the 850 EVO is still without a doubt one of the highest performing drives on the market. The smaller capacities are a bit of a disappointement, though, because the 250GB mSATA loses to MX100 by a quite hefty margin, but it still beats the Ultra II for what it's worth.

The smaller capacities, especially the 120GB one, seem to have quite a few high latency IOs. I wouldn't say the situation for the 250GB model is critical, but I do think that individuals with heavier workloads should focus on the 500GB and higher capacities in order to avoid any storage performance issues. 

But in terms of power the 850 EVO is very efficient at smaller capacities. Given that mSATA and M.2 standards are mostly used in mobile applications, this is very good news.