16 ноября 2005, 15:20

Microdrive – is not a flash memory yet, but not a hard drive already

Combine flash memory with a hard disk and look what will come out of this? <br> Microdrive – so small one as a chocolate "Alenka" is. Hitachi Global Storage Technologies begins shipping its 6Gb one-inch hard drive in high volume!

While reading a description of multi-card reader  you notice the main supported CF I, CF II, MD standards, here first two are quite clear, especially after review CompactFlash, as for MicroDrive – here everything is particular.
Tiny hard drive resembles a flash card. Hard disk - a device demanding the gentle reference! It is sensitive to any unexpected voltage swings, shake-ups and impacts. So, let’s look how can we solve these problems?

Of course there are many obvious advantages of using these tiny hard drives – price and capacity. No other product on the market can offer a better combination of storage capacity, portability, compact size, performance and affordability. You can find 6Gb and even 8Gb models now. CompactFlash of such size and capacity are rather expensive.

We were lucky to get on testing a Hitachi Microdrive HMS360606 D5 CF00
with 6Gb capacity. We have decided to make a close look - whether this format has a light future or not!

First contact

Microdrive view

Hitachi Microdrive 6Gb

Microdrive niz

Hitachi Microdrive – other side

When I held this Microdrive from Hitachi in my hands a sensation that it is a small chocolate did not leave me. Only iron surface and something rattling inside proved that was a hard drive. Device is not so frail as you think – it is impossible to break it without hammer, even CompactFlash cards in plastic cases will be less stronger.

This 6GB Microdrive provides vast, reliable storage for data, photos, music and videos, when inserted into compatible flash card slots in digital cameras, PDAs, handheld PCs, MP3 digital audio players, laptops and other portable digital devices.

General specifications I have found you may read here Hitachi, please open "Microdriver":

ModelHMS360606 D5 CF00
InterfaceCF+Type II
Capacity, Gb6
Sector size, bytes512
Areal density, Gbits/sq.inch, max78
Data buffer, Kb128
Rotation speed, RPM3600
Latency, average ms8,33
Media transfer rate, Mbits/sec67-125
Interface transfer rate, Mb/sec, max33 (Ultra DMA Mode 2)
Sustained data rate, Mb/sec4,9 – 9,4
Average seek time, ms12
Track to track, ms1
Full track, ms24
Time for load, s1
Error rate, non-recoverable\< 10-13
Load/unload cycles300000
Requirement power, V+3,3/+5
Current, write, mA230/280
Current, peak, mA13/15
Temperature, C0 – 70
Humidity, %8 - 90
Shock (half sine wave), 2ms200 G
Random Vibration (RMS) 5-500Hz0,67 G
One-Vibration 5-500Hz1G
Acoustics bels, idle typical, Db18
Physical size, mm42,8x36,4x5
Weight, g16

As we see here, real speed of microdrive depends on interface. Using of slots directly connected to IDE - possible to achieve quite a good media transfer rate - up to 9 Mb/sec, because as for USB-controller of any card reader it limits speed to 4-7 Mb/sec. In comperison with Hitachi Microdrive 3 K4-2 about 2Gb, which was tested two years ago (please look «Hitachi Microdrive 3K4-2», the speed increased double.

Besides, this tiny hard disk possesses of a high stability to any vibration and impacts and can easy maintain 300000 operations of heads parking. A secret of such survivability - technology Load/Unload!

Instead of Contact Start-Stop (CSS) technology has come Load/Unload. Before, reading heads parked directly on a surface of a plate, but now they placed on a special ramp. Even at unexpected failure of energy submission a contact with a disk is impossible: spindle’s residual rotation transforms to a current - quite enough for heads parking.


Parking of heads on ramp

Due to all these characteristics we can say with confidence that Microdrive Hitachi is an excellent memory card and a perfect replacement of Compact Flash. But, as you know every magnetic drive is very sensitive to static pressure and especially to strong magnetic fields, whereas flash-memory is not receptive to such influences at all.

Let's leave this issue what to choose and give the customers free hand! So, let’s start to test it.


In testing we will use the following system:

  • Sempron 2400+;
  • DIMM PC2700, 512 Mb;
  • Asus A7N8X-X;
  • nForce 2 v.44.07;
  • HDD Seagate ST380011A (80 Gb, 7200 rpm, Ultra-ATA 100);
  • ОС Windows XP SP1

Aslo in testing we used two card readers: the main – Transcend 7-in-1,
monitoring device – MC Corp 23-in-1. We have already used them in of multi card readers testing.

We used a test package Aida32 to define a character, to measure operating speed of the card and average time of access.

By means of Iometer v. 2004.07.30 we shall define microdrive's speeds with data of different size in 4 modes.

Real tests will be lead by means of FC-Test program. We shall define speed of copying of 100 files each 1 Mb, 10 files each 10 Mb and 1 file about 100 Mb.


Test has shown that card reader’s speed brings to nothing all characteristics declared before. It is known, that at linear reading there is a "step" schedule on which speed of internal paths is maximum and speed of external – doubled low.  We managed to receive only this schedule, even using of the fastest card reader:

lin read mc

Speed limited by card reader's controller

Direct line is up to 85 % - max speed. As a result, the average index - 4,48 Mb/sec. With Transcend – parameters are lower - 4,9 Mb/sec.

The most interesting, among of all parameters we have got, was the time of access - 22,5 ms, almost twice above declared one – due to card reader’s influence. Linear write speed was limited - 2,63 Mb/sec, casual read speed - 3,94 Mb/sec, casual write speed - 2,42 Mb/sec.


Testing results are in table, here. Third column - results showed by memory card CF Kingston Elite Pro 50x (please look «Universal Card Readers -Turtle Race», with Transcend)

SizeLinear read speed MDLinear write speed MDLinear read speed CFLinear write speed CF

Microdrive has the same linear read speed as flash memory, but the write speed is twice worse. But it so, data are well correlated with Aida32 results.

SizeCasual read speed MDCasual write speed MDCasual read speed CFCasual write speed CF

 We have got difference in time of access on casual read speed  of flash (nearby 1 мs) and microdrive (22 мs). As for casual write - for so slow result here is definitely guilty card reader.


Card reader, which we used, limited the speed of Hitachi, but the results of synthetic and practical tests, at the same time, are very close.

FilesWrite speed, MbRead speed, Mb
1x100 Mb2,094,01
10x10 Mb1,943,99
100x1 Mb1,883,78

Received results showed the same picture, as all previous tests. Media transfer rate is the same as CF-cards on average level have. Here, casual read speed and write speed were slow - these low parameters are caused of card reader’s restrictions.


When a maximum capacity comes first to you among of all requirements - in this case Hitachi Microdrive 6Gb - will be the best choice! Excellent to professional photographers working with a great amount of high-quality images! You can use this tiny hard disk everywhere you wish. In addition, such Microdrives are widely used in modern players and personal mediacenters. Hitachi Microdrive 6Gb has a high endurance and in using does not differ from CompactFlash card. Attention! Strong electromagnetic fields are harmful to Microdrive so, simply use a special protective package.


Microdrive in special protective package

Автор: Aleksandr Radaev