We'll kick things off with HD Tune, our synthetic benchmark of choice. Although not necessarily representative of real-world workloads, HD Tune's targeted tests give us a glimpse of a drive's raw capabilities. From there, we can explore whether the drives live up to their potential.
I've removed the SSDs and desktop drives from the line graphs because the data is too densely packed to be readable. Plus, Excel really doesn't have enough colors. If you'd like an idea of how the SSD transfer-rate profiles look in comparison, check out this page of our 7,200-RPM terabyte round-up.
So much for areal density dictating sequential throughput. The 750GB Momentus is a little slower than the Spinpoint in HD Tune's sustained read speed test, and although we don't know the Samsung drive's areal density, it's almost certainly lower than the Seagate's. In the battle of 500GB drives, the Travelstar edges out the Scorpio despite packing 30 fewer gigabits per square inch.
Right from the gun, it's apparent solid-state drives have a big performance advantage. What's more interesting is how these 7,200-RPM notebook models fare against other 2.5" mechanical drives. The Scorpio Blue spins its platters at 5,400 RPM and is a good 10MB/s slower than the Scorpio Black, putting it nearly 20MB/s behind the Spinpoint. Seagate's Momentus XT doesn't look so hot, either; it's slower than the Scorpio Blue despite having a 4GB solid-state read cache backed by 7,200-RPM mechanical storage.
In the line graphs, notice how the XT's transfer rates fall off quickly and oscillate more frequently than the purely mechanical drives. The transfer-rate profiles of our 7,200-RPM contenders are more consistent, although the Momentus' read speed falls off in more of a stair-step fashion than the others.
Switching to writes narrows the gaps between the 7,200-RPM notebook drives, but their order doesn't change. Even though the Momentus XT is a little more competitive this time around, it still lags behind the Scorpio Black. Our lone 5,400-RPM example remains a ways off the pace, as well.
SSDs tend to read faster than they can write, and that has interesting implications for this particular test. Although the fastest solid-state drives still rule the standings, our collection of notebook drives is quicker than Intel's budget X25-V and not much slower than the X25-M. Intel SSDs have traditionally had sluggish write performance, at least in tests of flat-out sequential throughput.
Before moving on, note the Spinpoint's more erratic oscillations in our line graph. They still average out to the highest sustained write speed, but it's a bumpier ride than with reads.
Next up: some burst-rate tests that should test the cache speed of each drive. We've omitted the X25-V RAID array from the following results because it uses a slice of system memory as a drive cache.
Our notebook drives might all have 16MB of DRAM onboard, but the speed of that cache differs between the various models. The Spinpoint and Travelstar flirt with 200MB/s in HD Tune's burst speed tests, while the Scorpio and Momentus languish 27-38MB/s behind.