When running the AS SSD Benchmarks sequential read test we find that the WD Black 4TB and Red 3TB drives offer the same performance, each sustaining 146MB/s. This made the WD Black 4TB roughly 25% slower than the Velociraptor 1TB while it was 11% faster than the WD RE 1TB.
This time when measuring sequential write performance the WD Black 4TB was a fraction faster than the WD Red 3TB as it sustained 146MB/s once again and again it was roughly 25% slower than the Velociraptor.
The 4K-64 Thread test is not a benchmark that plays nice with mechanical drives and as a result the WD Black 4TB was significantly slower than the Samsung SSD 840 Pro 512GB. When compared to other hard drives the WD Black 4TB performed quite well and was very consistent.
Access times are another huge strength of SSD technology and over the past few years we have become accustom to seeing times well below 1ms. However with mechanical drives the best you can hope for generally is a few milliseconds. The WD Black 4TB had a read access time of 16.792ms, which is pretty average really, making it much slower than the RE 1TB and Velociraptor 1TB in this test.
Whereas the read access time of the WD Black 4TB was quite average, the write performance is remarkable. The WD Black 4TB took just 2.170ms to access when measuring write performance, making it faster than the RE 1TB and Velociraptor 1TB.