Results: Sequential Performance
Fantastic sequential read and write performance is a trademark of modern SSDs. To measure it, we use incompressible data over a 16 GB LBA space, and then test at queue depths from one to 16. We're reporting these numbers in binary (where 1 KB equals 1024) instead of decimal numbers (where 1 KB is 1000 bytes). When necessary, we also limit the scale of the chart to enhance readability.
128 KB Sequential Read
We're pitting the SSD340 against a select group of 256 GB-class offerings. All four use 16 KB page sizes, and all four employ 128 Gb dies.
Right out of the gate, there aren't many meaningful observations to make. The dip we've seen from other 128 Gb L85A-equipped SSDs with a single outstanding 128 KB read command affects Transcend's drive as well. Only Adata's SP920 stands out from the group.
128 KB Sequential Write
These results are somewhat disappointing, at least compared to the pricier drives in our comparison. The Adata sells for $150, Transcend's SSD340 is $115, and Crucial's slightly quicker M500 is also priced at $115. But Transcend can't catch the comparably-priced Crucial drive in our sequential write speed benchmark, and that was already one of the slower drives we've tested recently.
Meanwhile, Plextor's four-channel M6S hangs the rest of the field out to dry with its complement of 128 Gb Toshiba A19 Toggle-mode flash. That's a $145 offering.
Here's a breakdown of the maximum observed 128 KB sequential read and write performance with Iometer: