Both Western Digital's WD WD7500BPKT Scorpio Black and Toshiba's MK7559GSXP share the same 750GB capacity and Advanced Sector Formatting (ASF) technology.
But the Scorpio Black has a spin speed of 7,200rpm and 16MB of cache. Compared to the Toshiba's 5,400rpm spin speed and just 8MB cache, the Scorpio Black has much better burst speed performance.
That said though, both the Toshiba 750GB and Toshiba 1TB drives are much better value.
Burst speed performance
Random access performance
Price per gigabyte