Nearly 18 months ago, we published a review (link) of the then new Seagate 7200.11 1Tb, comparing it with the previous generations. Since then Seagate has stayed in the headlines for the 7200.11 series – and not for the best of reasons. Defective firmware leading to inaccessible drives caused a major splash and anecdotal evidence of large numbers of drives being RMA’d have steered popular opinion away from Seagate.

Many have criticized Seagate’s handling of the firmware problems, with initial slowness to publically address issues, fuzziness on which drives were affected and culminating in the vendor offering free data recovery services for those with bricked drives, with advanced exchanges for select customers. Our own Rage3D Administrator Lupine chronicled his issues with affected drives, RMA’ing problem drives and receiving drives with the same problem firmware back.

In the meantime, I had left my four Seagate 7200.11 1Tb drives doing backup duty as a RAID 5 set in an external enclosure. The original SD01 firmware stood the test of time, with no random rebuilds, dropped drives or poor performance seen – workhorses, all around. Moving to a new backup architecture, the drives became free once more for a revisit: new firmware, SD1A. Like before, no extravagant testing methods were used – just throw HDTach’s long bench at it three times and average the results.

I connected the four ST31000340AS drives to my Gigabyte GA-EP35-DS3R’s Intel ICH9R controller, and used Vista Ultimate SP1 x64 to run HDTach for some simple numbers.  Like the previously used discrete LSI and Adaptec controllers, Intel’s ICH matrix integrated raid solution offers a Write Cache. Initially this mode was introduced for RAID 5, where writes are coalesced to reduce the number of I/O’s per write for parity calculations for sequential data streams. This means if four sequential 16Kb access requests have been made, the 16K I/O’s are combined into a single 64Kb access. Intel Matrix Storage utilizes a cache for write buffering and to improve coalescing for desktop usage models, such as Raid 0 or 1, and AHCI. Approximately 4Mb of main memory is allocated for cache at boot time. Recent driver updates have allowed this write cache to benefit AHCI as well as RAID volumes, such that all IMS arrays benefit for burst read rates – in benchmarks, at least. As the writes are cached, subsequent reads from that same data will come from cache and not the disk, increasing data access speed. Obviously, this cache is sensitive to system configuration – the faster and lower latency the system memory, the better the cache performs.

Ideally the cache should be write-though – the data is written to the disk and kept in the cache for faster reads, vs. write back mode where data is flushed from cache periodically. In this mode data is very sensitive to power reliability and system stability; a bad overclock, system crash or a power interruption could not only cause data loss but operating system corruption if critical files are not written to disk.

To account for this, the tests were performed with the write cache enabled, and disabled, via the Intel Matrix Storage Manager. The CPU used in the system was an Intel Xeon X3210 B3 quad core processor, clocked at 3Ghz, with 4Gb of Buffalo Firestix DDR2 ram running at 900Mhz 5-5-5-15.

Seagate claims 105MB/sec maximum transfer rate for the ST31000340AS, which was verified in HDtach for the first 20% (200 GB) of the drive, in single disk configuration. Interestingly, the ST31000333AS 1Tb and ST3150041AS 1.5Tb drives are rated at 115MB/s and 120Mb/s, respectively. Those of you taking advantage of the recent sales on 1Tb and 1.5Tb drives are getting some fast drives, cheap.