256GB SSD Performance
Moving down the capacity range to 256GB products pits the HP S700 Pro against the Corsair Force LE 200, Muskin Triactor, Samsung 850 EVO, and SanDisk Ultra II. Since Tom's Hardware caters to gamers and enthusiasts, we rarely receive 256GB-class SSDs anymore. The performance of newer drives with higher-capacity NAND die tend to fall off rapidly even though the new flash is technically faster. SSD performance comes from reading and writing in parallel to several die at the same time. The numbers fall off balance when you pair high capacity dies with low capacity SSDs, and that hurts mixed workload performance.
Sequential Read Performance
The HP S700 Pro 256GB will have a difficult time competing in this capacity against products using lower-capacity die, like the Toshiba 15nm planar TLC that is 1/3 the capacity. That means drives like the SanDisk Ultra II have a three-to-one die count advantage. That helps with parallel read and write operations.
Sequential Write Performance
None of that seemed to hurt the HP S700 Pro during the sequential write workload. The drive came out on top among our comparison drives, but we'll take a deeper look at the mixed sequential performance a little later in the review.
Random Read Performance
The S700 Pro 256GB fell flat in our random read test. The drive even trails the DRAMless Force LE 200 240GB SSD. The S700 Pro has trouble scaling performance as the queue depth increases, too. We're more concerned with the low QD performance.
Random Write Performance
This drive seems to have trouble finding a middle ground. When it's working well, the S700 Pro 256GB is on top. But when it's down, it seems to suffer more than other SSDs. The random write test seems to be the exception, but the drive pulls ahead of the other products with more load from increased queue depths.
80% Mixed Sequential Workload
With high sequential performance in both the read and write workloads, the HP S700 Pro performs well in our mixed workload. The S700 Pro stands alone at QD2, and that carries over to QD4. Beyond that, the 850 EVO catches up.
80% Mixed Random Workload
The low mixed workload performance seems to apply to the entire series. The 256GB model encounters the same issues at high queue depths but also performs well at low queue depths where most consumer workloads reside. We wouldn't worry about the scaling issues too much (unless you run a frequently accessed database).
The sequential steady-state performance is similar to the larger HP S700 Pro in performance. This workload is well outside of the intended use for this product, but you will notice a significant performance drop-off when the drive is nearly full.
Historically, SMI controllers have had issues with performance consistency. The cache system will flush at odd times, and all of the data travels through the SLC buffer before folding the data to the TLC NAND. Other companies have found that, when the buffer is full, it's better to write directly to the TLC NAND (direct-to-die writes). The data in the SLC buffer will later pass to the TLC once the drive has some idle time to make the flush. SMI doesn't use the more effective method at this time.
PCMark 8 Real-World Software Performance
For details on our real-world software performance testing, please click here.
The HP S700 Pro 256GB isn't a bad drive for daily use software under light workloads, but it's not the best either. The price is a little higher than we like, but primarily because faster products also cost a little less.
Application Storage Bandwidth
With an average throughput rating, we can easily see how the drives pan out. The HP S700 Pro 256GB trails the Samsung 850 EVO 250GB by 50 MB/s with daily-use software.
PCMark 8 Advanced Workload Performance
To learn how we test advanced workload performance, pleaseclick here.
The drive doesn't recover well when the workload lightens. The recovery phase gives each drive a five-minute reprieve on IO activity so background activities can catch up and clean cells for new incoming data, thus recovering lost performance. The S700 Pro recovers, but at a very slow rate. It also takes much longer to reach peak speeds again.
Total Service Time
The service time test shows the high latency associated with heavier workloads and the slow recovery time.
Disk Busy Time
The service time test reveals that the S700 Pro 256GB has to work longer than many of the other SSDs to complete the same number of tasks.
The SYSmark 2014 SE Responsiveness Test show the 256GB drive performing slightly better than the 512GB during very light office workloads. The power consumption is still very high. Not long ago I explored the performance of several older SSDs like the SandForce SF-2281-powered Intel SSD 520 Series that came to market in 2012. The HP S700 Pro trailed the aging 520 Series in both responsiveness and power consumption.
Notebook Battery Life
The 256GB HP SSD again trailed the other test drives in the notebook battery life test using MobileMark 2012.5. You will lose around one hour of battery time for every six hours of use with a Lenovo Y700-17. The lost battery time would increase on a system that consumes less power or has a larger battery, like a business-focused notebook.
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