The Team Group T-Force Cardea (240GB) SSD Review: Grace Under Write Pressure

Random Read Performance

Our first test of random read performance uses very short bursts of operations issued one at a time with no queuing. The drives are given enough idle time between bursts to yield an overall duty cycle of 20%, so thermal throttling is impossible. Each burst consists of a total of 32MB of 4kB random reads, from a 16GB span of the disk. The total data read is 1GB.

The Phison E7 drives vary widely in their QD1 random read performance. The Team T-Force Cardea isn't the fastest, but it's above average and faster than the SATA drives.

Our sustained random read performance is similar to the random read test from our 2015 test suite: queue depths from 1 to 32 are tested, and the average performance and power efficiency across QD1, QD2 and QD4 are reported as the primary scores. Each queue depth is tested for one minute or 32GB of data transferred, whichever is shorter. After each queue depth is tested, the drive is given up to one minute to cool off so that the higher queue depths are unlikely to be affected by accumulated heat build-up. The individual read operations are again 4kB, and cover a 64GB span of the drive.

On the longer random read test that includes some moderate queue depths, the T-Force Cardea is the fastest Phison E7 drive and slightly faster than the best SATA drive, but clearly slower than most NVMe drives.

In addition to being the fastest Phison E7 drive on the random read test, the T-Force Cardea is also the most power efficient. However, every other M.2 or SATA SSD in this bunch is more efficient than the Phison E7 drives. The Samsung 850 EVO, while slightly slower, delivers twice the efficiency.

Team T-Force Cardea 240GBSamsung 950 PRO 256GBSamsung 960 EVO 250GBPatriot Hellfire 480GBOCZ RD400 256GBIntel SSD 750 400GBCorsair Neutron NX500 400GBZotac SONIX 480GBSamsung 850 EVO 250GBSamsung 850 PRO 256GBPNY CS2211 240GB

At higher queue depths, the random read performance of the Team T-Force Cardea is identical to that of the larger Patriot Hellfire, while the Corsair Neutron NX500 hits the highest speeds out of the Phison E7 drives. The Samsung 960 EVO has a small lead over the T-Force Cardea, and that lead widens with increasing queue depth.

Random Write Performance

Our test of random write burst performance is structured similarly to the random read burst test, but each burst is only 4MB and the total test length is 128MB. The 4kB random write operations are distributed over a 16GB span of the drive, and the operations are issued one at a time with no queuing.

The burst random write performance of the Team T-Force Cardea is second-fastest among the Phison E7 drives, but relatively slow among the wider field of NVMe competition.

As with the sustained random read test, our sustained 4kB random write test runs for up to one minute or 32GB per queue depth, covering a 64GB span of the drive and giving the drive up to 1 minute of idle time between queue depths to allow for write caches to be flushed and for the drive to cool down.

When longer run times and higher queue depths come into play, the T-Force Cardea and other Phison E7 drives look better. The Intel 750's random write performance can't be matched, but the Cardea is well ahead of Samsung's small NVMe drives.

The Team T-Force Cardea and the Patriot Hellfire are tied for first place in random write power efficiency, with a clear lead over the OCZ RD400 and Samsung's drives.

Team T-Force Cardea 240GBSamsung 950 PRO 256GBSamsung 960 EVO 250GBPatriot Hellfire 480GBOCZ RD400 256GBIntel SSD 750 400GBCorsair Neutron NX500 400GBZotac SONIX 480GBSamsung 850 EVO 250GBSamsung 850 PRO 256GBPNY CS2211 240GB

The random write performance of the T-Force Cardea scales very will with increasing queue depth until the drive runs out of spare area and needs to perform garbage collection. The larger Phison E7 drives were able to make it through the entire test without performance falling off, while the smaller Samsung NVMe drives never reached particularly high performance to begin with.