Posted - 03/14/2010 : 11:05:43 AM
| HD Tach 3.0.4 1.1MB .exe windows installable utility.
Freeware, $49.95 for version with Write test.
Windows XP, 2K Only. Will not run on Vista, Windows 7 Unknown.
HD Tach is a rather unique hard drive test/benchmark utility that uses a special kernel mode VXD to bypass the operating system file system to test the actual drive and interface regardless of how the data is structured.
HD Tach hs two read tests.
Average Sequential Read, and Burst Speed read.
It also shows an Average Random Seek Time.
While most benchmarks create a file on the hard drive and test within that file, that causes a biased result because modern hard drives use a zone bit recording technique that allows different read speeds depending on where the data is located, and it uses the actual file system.
HD Tach reads from areas all over the hard drive and reports an average speed.
It pays no attention to partitions and tests the whole drive randomly.
HD Tach also tests the drive burst speed.
The burst speed is the speed that data can be accessed from the drive's on-board read-ahead memory. This measures the speed of the drive and controller interface, and often the number that manufacturers claim as thir "Up to..." Bla Bla Bla speed.
*Regarding the drive interface... Just because the drive has a SATA connector does not mean it is a true SATA controller, or that it can go anywhere near the speed of the stated connection.
In addition to sequential and burst read, HD Tach tests the drive's random access time.
Random access is the true measure of seek speed.
Many drives advertise sub 10 millisecond seek speeds, but seek speeds are misleading when measured sector to sector and not truly an average of random seeks over the entire drive.
I really like this little stand alone utility.
It is fast ( a minute or two), and it allows you to compare true drive/interface speeds from machine to machine regardless of the data, and varies little from to test to test.
For example unlike most benchmarks, defraging your drive won't help this test, what the data is or how it is structured is irrelevant.
In short, this is the fastest your drive can physically go.
Once you add file system management like defrag into real life use, all that you can do is try to approach this true max limit with file structure management.
Just unzip the HDtach .exe file and run it to install program.
The startup screen lets you choose a drive to test.
Remember, this tests the whole drive, not a given partition, it just lists the partitions for reference, and of course your drive with the C: boot partition is the most important to you.
You can choose the short 8MB, or longer 32MB test.
The program gives to graphs and a text readout, but to save space here I will just use the bottom portion.
250GB Samsung HD252HJ SATA300 7200RPM 16MB RAM Buffer - Boot Drive.
8MB Quick Test:
As you can see the average Seek and Read speeds varied little from from test to test, as this is overall performance, and the average 77-79MB/s transfer rate would be fine on a SATA 150MB/s bus.
The 8MB Burst was much faster than the 32MB Burst because it only has 16MB of RAM Buffer, had the drive had a 32MB Buffer, or the test be 16MB, burst would be even faster.
*Hence how drive manufacturers will also taylor their Burst (Up to...) Tests to the RAM on the drive.
Regardless, in both cases the Burst speed is way over the SATA 150 limit and therefore needs the SATA 300 interface to carry it.
160GB Maxtor STM3160812 SATA150 7200RPM 8MB RAM Buffer - Data Drive
8MB Quick Test:
The MAX has the same spin speed as the Sam and even slightly better seek times, but still much slower than the Sam, and it is not due to the SATA150 interface.
With a little research I discovered that Maxtor simply put a SATA 150 interface connector on the drives original IDE ATA100/133MB controller circuit.
Sure, you could argue that it made that drive compatible with the growing SATA connection age, but it didn't use the added bus speed, and at a 8MB Buffer matched Burst of 131MB/s and average Read of 61MB/s it is pretty slow for a SATA drive.
That may not seem like much of difference, but when you graph them together you can really see the difference, and HD Tach lets you save your results and compare two drives with the Graph Data option.
You can click the Save Results button after a test for later use.
You first get a screen to fill in your system info, you don't need to but if you use the Upload Results button it is useful.
The default save folder is:
Give the .hdc file a name and you can use it later.
*NOTE! I get a memory error every time I save that closes the program, but it saves.
Also note that when you close HD Tach after a save it doesn't go away!
I think this has to do with the VXD bypass and you need to kill 3 processes all starting HDtach to kill it.
Buggy yes, but it gives good results.
Also, when you go to Graph or Compare your saved results from the Data Source: Your Saved Benchmarks list it does NOT use the name you gave it, it display the drive name for all of them despite options to sort on everything else, so I use the date/time or Average Read to know what is what.
You can download my Samsung KCsamsung8MB.hdc and KCsamsung32MB.hdc tests, drop them in your
C:\Program Files\Simpli Software\HD Tach directory, and comapre your drive against mine from Your Saved Benchmarks.
Here is my drive comparing the 8MB (Blue)and 32MB (Red) tests.
For under $100 I like it.
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