I just bought a Western Digital Caviar Black WD7501AALS 750GB (SATAII, 7200 RPM, 32 Mb cache). I ran a few disk benchmarks on it and found that is seems pretty darn slow compared to my Seagate drives. Does anyone else have this WD drive and would you mind running HD Tach on it if you run windows or hdparm if you run LINUX and report the results. Here are the results using HD Tach under XP Pro 64-bit: Random access: 14.3ms Average read: 89.6 MB/s Burst Speed 224.9 MB/s Here are the results under LINUX using hdparm # hdparm -Tt /dev/sda /dev/sda: Timing cached reads: 13500 MB in 2.00 seconds = 6761.12 MB/sec Timing buffered disk reads: 244 MB in 3.02 seconds = 80.92 MB/sec As a comparison, I ran the same two benchmarks on my Seagate ST3750330AS (also 750 Gb, 7200 RPM, 32 Mb cache): Here are the results using HD Tach under XP Pro 64-bit: Random access: 12.9ms Average read: 91.4 MB/s Burst Speed 247.6 MB/s Here are the results under LINUX using hdparm # hdparm -Tt /dev/sda /dev/sda: Timing cached reads: 15880 MB in 2.00 seconds = 7952.77 MB/sec Timing buffered disk reads: 344 MB in 3.01 seconds = 114.19 MB/sec
Hmm.. Both are 3-platter designs with similar platter capacities (250 GB per platter). The faster access speed does suggest that the Seagate drive may have a slightly higher areal density.
I might just have to return this one and get the 1 TB model then... either that or the new Seagate which I can't find anywhere (the 7200.12).
But honestly, it doesn't really matter that much unless you are fully utilising the file transfer speed. 1ms faster random seek time is something you should take into consideration also.
Yeah, the 1TB WD Caviar Black should be faster. It has 1 TB on 3 platters, so the areal density is 33% higher. Its platter-to-buffer transfer rate should correspondingly be roughly 33% higher.
Not really, the 1TB model has 6 heads, and the 750TB has 5 heads...so the 750 is not using one side of one platter. So the per platter densities are not that much different, and as such I doubt you notice an improvement. I suspect the 750 is just a 1TB drive that failed testing on one side of a platter...probably has all 6 heads but one is disabled.
Hmm.. You are right. My mistake. Don't know how I missed that. The areal density of both 1TB and 750GB models are almost the same - they both have 3 platters, but the 1TB model has 6 heads while the 750GB model has only 5 heads. From the specs which lists both drives as having the same platter-to-buffer transfer rates, it is likely that both drives have the same areal density.
There are 1TB drives with just only 2 platters ... Mind you why do you think there are 2TB drives. Pls come back to present, don't be left behind ....
