Sequential Performance – HDTach, HDTune, File Copy, YAPT (sequential)

We have shifted over to combining our results into two groupings for consumer reviews. First up is sequential performance:


HD Tach will test the sequential read, random access and interface burst speeds of your attached storage device (hard drive, flash drive, removable drive, etc). All drive technologies such as SCSI, IDE/ATA, 1394, USB, SATA and RAID are supported. HDTach tests sequential performance by issuing reads in a manner that was optimized more for HDD access, but this unique method has proven useful in evaluating the sequential response time of SSDs. The accesses are relatively small in size (2k), and are issued with a single working thread (QD=1). The end result is that devices with relatively IO high latency will not reach their ultimate rated speed.

With QD=1 and small sequential reads taking place, the SSD 750 gets unseated by Samsung's NVMe SM951.


HDTune tests a similar level of features as compared with HDTach, but with a different access pattern. Thus provides us with an additional set of benchmark numbers to compare between storage configurations. CPU utilization has proven negligible with modern processing horsepower, and is no longer included. Additionally, we do not include write performance due to HDTune's write access pattern not playing nicely with most SSDs we have tested it on.

We have HDTune configured to perform large block reads, but those reads are not 4k aligned, so we see the SSD 750 fall behind newer faster controllers present in the new SM951, as well as the Marvell 88SS9293 controller present in the Kingston HyperX Predator.

PCPer File Copy Test

Our custom PCPer-FC test does some fairly simple file creation and copy routines in order to test the storage system for speed.  The script creates a set of files of varying sizes, times the creation process, then copies the same files to another partition on the same hard drive and times the copy process.  There are four file sizes that we used to try and find any strong or weak points in the hardware: 10 files @ 1000 MB each, 100 files @ 100 MB each, 500 files @ 10 MB each and 1000 files at 1 MB each.

Yes, you read that right. A fire breathing Intel SSD 750 was just unseated by a couple of tiny M.2 SSDs. Once again records are broken in this test, this time by the NVMe version of the SM951. The SSD 750's enterprise pedigree heavily optimizes for 4k and higher random access, and writing very small files with our tool means a lot of <4k file table updates, slowing things down a bit.

Windows file copies are a bit more multithreaded, allowing the SSD 750 to win out on many of the file copy rounds. Multithreaded copies was not sufficient to beat out the SM951 when copying 1000 1MB files, however.


YAPT (yet another performance test) is a benchmark recommended by a pair of drive manufacturers and was incredibly difficult to locate as it hasn't been updated or used in quite some time.  That doesn't make it irrelevant by any means though, as the benchmark is quite useful.  It creates a test file of about 100 MB in size and runs both random and sequential read and write tests with it while changing the data I/O size in the process.  The misaligned nature of this test exposes the read-modify-write performance of SSDs and Advanced Format HDDs.

YAPT has always done a great job of maxing out SSDs, and the same applies here. The SSD 750 holds the crown with nearly 2.6 GB/sec reads. The new NVMe SM951 sits on par with the G.Skill Phoenix Blade (which is internally 4x SATA SSDs).

On writes things are flipped a bit. The SSD 750 has a lower write speed limit than the AHCI version of the SM951, while beating the lesser rated NVMe variant by a hair.

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