Data Transfer Diagrams: Budget Drives
Maxtor 536DX 4W060H4
As you can see, the Maxtor drive starts at approximately 28 MB/s and descends to 16 MB/s. That can be called average performance today. Due to verifying algorithms, the write performance clearly lags behind the read performance.
Seagate's budget drive generates a "hectic" graphic. The data transfer performance does not descend steadily, but erratically. At the end of the medium, the read performance drops to even < 10 MB/s at some points - this drive is unsuitable for appliations that require a constant data stream. Write performance is also quite low, but hey, this 60 GB drive that only costs $ 140.
Western Digital WD600AB
The maximum data transfer performance in the graphic later on is not great, as it drops to 26 MB/s immediately. Although this drive might look fast at first, a glance at the performance diagram makes it clear that its speed is only average.