The HP S700 And S700 Pro SSD Review

Sequential Read Performance

Our first test of sequential read performance uses short bursts of 128MB, issued as 128kB operations with no queuing. The test averages performance across eight bursts for a total of 1GB of data transferred from a drive containing 16GB of data. Between each burst the drive is given enough idle time to keep the overall duty cycle at 20%.

The S700 and the larger two S700 Pros have great burst sequential read speeds, while the smallest S700 Pro has a bit of trouble (but still manages to outperform the smallest ADATA SU800 by 27%).

Our test of sustained sequential reads uses queue depths from 1 to 32, with the performance and power scores computed as the average of QD1, QD2 and QD4. Each queue depth is tested for up to one minute or 32GB transferred, from a drive containing 64GB of data.

On the longer sequential read test, the S700 doesn't drop to the bottom of the chart and instead offers above-average performance. The S700 actually has the fastest low queue depth sequential read speeds of any SATA SSD with Micron's 32L 3D NAND, including the MLC-based Crucial BX300. The S700 Pro is far slower and only its 128GB model beats the comparable ADATA SU800. We've asked HP if they can shed some light on how the S700 manages to deliver such an outstanding sequential read speed, because this is a very surprising result.

With good performance by TLC standards combined with the low power draw of a DRAMless Silicon Motion controller, the HP S700's power efficiency during sequential reads is great. The S700 Pro is near the bottom of the chart, but is a clear improvement over the ADATA SU800.

HP S700 Pro 512GBHP S700 Pro 256GBHP S700 Pro 128GBHP S700 500GBHP S700 250GBHP S700 120GBIntel SSD 545s 512GBSamsung 850 EVO 250GBSamsung 850 EVO 500GBSamsung 850 PRO 128GBSamsung 850 PRO 256GBSamsung 850 PRO 512GBPNY CS1311 120GBPNY CS1311 240GBPNY CS1311 480GBPNY CS2211 240GBPNY CS2211 480GBCrucial MX300 525GBADATA Ultimate SU800 128GBADATA Ultimate SU800 256GBADATA Ultimate SU800 512GBOCZ VX500 256GBOCZ VX500 512GBCrucial BX300 480GB

Only a few drives have trouble delivering full performance for sequential accesses at QD1, and the HPs aren't on that list. The S700's performance is both higher and more stable across the test than the S700 Pro.

Sequential Write Performance

Our test of sequential write burst performance is structured identically to the sequential read burst performance test save for the direction of the data transfer. Each burst writes 128MB as 128kB operations issued at QD1, for a total of 1GB of data written to a drive containing 16GB of data.

The HP S700 is just a bit slower than average for burst sequential write speed, and the S700 Pro is right around the average. The Crucial MX300 and the smallest ADATA SU800 are the only real outliers on this test.

Our test of sustained sequential writes is structured identically to our sustained sequential read test, save for the direction of the data transfers. Queue depths range from 1 to 32 and each queue depth is tested for up to one minute or 32GB, followed by up to one minute of idle time for the drive to cool off and perform garbage collection. The test is confined to a 64GB span of the drive.

The longer sequential write test shows that the 120/128GB class drives are at a significant disadvantage, but the S700 Pro performs well among that cohort. The larger S700 and S700 Pro drives all offer decent sustained sequential write speeds and rank quite a bit higher than for the shorter sequential write test.

The larger two S700s join the OCZ VX500 at the top of the efficiency chart for sequential writes, and the larger S700 Pros aren't far behind. The smallest S700 Pro is far less efficient than its larger siblings, but offers 60% higher performance per watt than the ADATA SU800 and is in the top of its class (again, not counting the discontinued Samsung drives). The 120GB S700 has the lowest efficiency.

HP S700 Pro 512GBHP S700 Pro 256GBHP S700 Pro 128GBHP S700 500GBHP S700 250GBHP S700 120GBIntel SSD 545s 512GBSamsung 850 EVO 250GBSamsung 850 EVO 500GBSamsung 850 PRO 128GBSamsung 850 PRO 256GBSamsung 850 PRO 512GBPNY CS1311 120GBPNY CS1311 240GBPNY CS1311 480GBPNY CS2211 240GBPNY CS2211 480GBCrucial MX300 525GBADATA Ultimate SU800 128GBADATA Ultimate SU800 256GBADATA Ultimate SU800 512GBOCZ VX500 256GBOCZ VX500 512GBCrucial BX300 480GB

The 500/512GB HP drives and the 250GB HP S700 don't saturate until QD4, while the 256GB S700 Pro manages to saturate at QD2. The 128GB S700 Pro runs out of spare area while the test is at QD2, so it never comes close to sustaining a speed that saturates the SATA link. The 120GB S700's performance is relatively consistent and increases somewhat with queue depth, but is overall still quite slow.