Four-Corner Performance Testing
The table below contains the comparison units for today's review:
Sequential Read Performance
The Vector 180 960GB starts off with a sequential read rate just over 420 MB/s at a queue depth of one. Remember that these results follow a conditioning pass, so the numbers are lower than OCZ's claims. Once eight commands are queued up, the Vector 180 is running at full speed, limited by the SATA interface.
We measure sequential read performance at a queue depth of two. There, the Vector 180 960GB delivers 500 MB/s, which is respectable. However, that's less than many other high-end drives.
Sequential Write Performance
Our sequential write performance results show a wave pattern that's the result of conditioning. There are some other write issues we'll explore on the next page.
A result of nearly 520 MB/s puts the Vector 180 just under Samsung's 850 with TurboWrite technology from an SLC cache layer.
Random Read Performance
The Vector 180's random read performance is lower than several competing products, at least until OCZ's latest offering is presented with deeper queues. There, random reads catch up to the rest of the field, limited by SATA 6Gb/s. Down low is where we need to focus though; that's more reflective of real-world performance.
The Barefoot 3 controller is starting to show its age, unable to deliver 10,000 random read IOPS at a queue depth of one, and trailing significantly at a queue depth of four. With 32 outstanding commands, though, OCZ can claim 100,000 random read IOPS like many of the others.
Random Write Performance
Random write performance is all over the place in our conditioned environment. On the next page, we'll explain in greater detail why the Vector 180's buffer flush causes so many issues with our testing and your real-world experience.
The Vector family is known for its alacrity in low queue depth, random write performance. This advantage remains at a queue depth of one. But at a queue depth of two, other products already surpass the Vector 180's best effort. OCZ does manage to hit the 90,000 random write IOPS its spec sheet claims. That level of performance comes at a queue depth of 16 in our testing, though, as you can see, the IOPS roll back further up the scale.