1TB Performance Testing
Galax HOF PCIe (1TB)
Here it is, the pivotal point in history, old meets new for the first time. We've stacked the charts with nearly every 1TB NVMe SSD available. There is a mix of older, newer, and even impossible-to-find drives on the list. We mixed both MLC and TLC to fill the charts to the brim.
This is a very diverse group. Intel has two products that represent the old and the new. The Intel SSD 750 1.2TB with MLC NAND was one of the first NVMe drives we tested. It has enterprise DNA that makes it big and expensive. The 600p is on the other side of the Intel NVMe camp with low-cost 32-layer 3D TLC technology.
The Galax HOF PCI-E is the only 1TB drive with a Phison PS5007-E7 controller. It's one of the rarest SSDs we've tested; it's only sold in Asia, and even there it's considered rare. There will be other E7 1TB-class products coming to the market very soon, though.
Both Plextor and Samsung have two drives in the charts in both MLC and TLC flavors. On the MLC side, we have the Samsung 960 Pro and Plextor M8Pe. The 960 EVO and M8Se use TLC NAND.
The Toshiba OCZ RD400 is the last drive in the group. We include both the RD400 and RD400a. The RD400 uses an add-in card adapter and the RD400A is an M.2 model.
Sequential Read Performance
It's possible to reach higher levels of performance with NVMe SSDs by testing with multiple workers, but we still use a single worker for our tests because most software still uses a single thread to access storage devices. We did reach up to 3,000 MB/s of sequential read throughput with multiple workers. That declined to 2,150 MB/s with a single worker.
The XG5 is still below 1,500 MB/s at queue depth (QD) 2, which is slower than the OCZ RD400. The RD400 arrived well after the XG3 OEM model shipped and includes an optimized NVMe driver. Currently, the XG5 doesn't have an optimized driver.
Sequential Write Performance
We have to admit that the new BiCS NAND just made our jaw drop. Even without an optimized driver, the XG5 just crushed the sequential write test. The QD1 test wasn't all that exciting, but the drive takes off at QD2 and even outperforms the Samsung 960 Pro, which is considered the fastest consumer SSD ever made.
The XG5's sequential write performance is also very consistent as we increase the queue depth. The older XG3 and RD400 both suffered from thermal throttling in this test, as you can see in the RD400 plot.
Random Read Performance
I hate to keep bringing up the optimized driver issue but it's an important aspect. In our testing, random read performance experiences the biggest performance boost from the small piece of driver code. The Toshiba XG5 is at the bottom end of our random read chart with less than 10,000 IOPS at QD1, but we suspect the OCZ version will receive a significant bump. The RD400 is nearly 3,000 IOPS faster at QD1, and the Samsung 960 Pro holds nearly a 7,000 IOPS advantage at the same queue depth.
Random Write Performance
The XG5's random write IOPS performance, which is lower than the RD400, doesn't come as a surprise. TLC will have a very hard time closing the random write gap with MLC flash. All the drives at the bottom of the low-QD chart utilize 3-bit per cell NAND.
80% Mixed Sequential Workload
We added charts to better show the scale of the 80-percent read mixed workload test. The NVMe products are not as congested as the SATA SSDs, but the extra chart helps clarify the results. The XG5 is the highest performing drive with TLC flash, but it's well under the RD400.
80% Mixed Random Workload
Mixed random performance is our main concern with TLC flash. The XG5 falls right behind the 850 EVO 1TB at most queue depths.
The sequential steady-state test reveals a nice uptick on the 100% write end of the chart. All of the other TLC-based SSDs, other than the 850 EVO, fall off during the write portion of the test. Toshiba managed to get MLC-like performance out of BiCS NAND in steady state. It's not as fast as the outgoing 15nm MLC, but it's certainly better than planar TLC.
The Toshiba XG5 is one of the first TLC-based SSDs to deliver consistent performance in the steady-state random write test. The XG5 is still 10,000 IOPS slower than the Samsung 850 EVO 1TB, though.
PCMark 8 Real-World Software Performance
For details on our real-world software performance testing, please click here.
The Toshiba XG5 1TB is impressive even without an optimized driver. In many of the tests the XG5 is right on the heels of the 960 Pro.
Application Storage Bandwidth
Thanks to a 400 MB/s sequential read increase over the RD400 and a high-performance SLC buffer for the data writes, the XG5 is slightly faster than OCZ retail drive. The XG5 even managed to outperform the Intel SSD 750 1.2TB with MLC and an 18-channel controller.
PCMark 8 Advanced Workload Performance
To learn how we test advanced workload performance, please click here.
The Toshiba XG5 delivers consistent performance in our two steady-state tests, but it suffers wild swings in our PCMark 8 Extended Storage Test. This may be the result of thermal throttling during the 24-hour test cycle. It may also be why Toshiba brought this controller to market with an exposed flip-chip design. Phison's E7 ships in both covered and uncovered form, even though we've only seen the covered version once. We inquired about the covered design and were told the extra casing adds a few degrees to the temperature.
Total Service Time
The XG3 / RD400 has a bit of a thermal issue. We used it for an upcoming M.2 cooling article after finding it could benefit from a low-cost cooling solution. The wild service time performance may be a result of throttling, but the RD400 didn't experience the same condition during the test.
Disk Busy Time
We don't know enough about the Toshiba XG5's controller or BiCS NAND to know the source of the increased latency. It carries over to the disk busy time measurements, as well.
During heavy workloads we see latency spikes, but the XG5 settles down during lighter workloads. It's typical behavior for a TLC-based SSD, but we hoped this drive would be different.
Toshiba still has some optimization work. We run the SYSmark 2014 SE Responsiveness Test in a Lenovo Y700-17, and it uncovers latency issues with the XG5. The enclosed space in the notebook may cause thermal throttling. We'll have to explore more before the retail OCZ RD drive comes to market.
Notebook Battery Life
Compared to the XG3 1TB, the Toshiba XG5 1TB adds twenty-one minutes to our MobileMark 2012.5 notebook battery life test. We tested both XG series drives with the Microsoft Windows 10 NVMe driver. We tested the RD400 1TB with the performance optimized driver and it delivered twenty-seven minutes less battery life than the XG5.
MORE: Best SSDs
MORE: All SSD Content