Hard Disk Subsystem
This part of the ZPC is another bottleneck. The computer uses a hard disk drive and an optical drive designed for notebooks. That is, a 2.5” HDD and a “slim” CD-ROM drive. First, let’s see how they are attached to the system and then I will explain why I consider them a not very successful solution.
There is a special daughter-board, which is attached to the mainboard (see the photo above). It is plugged into the IDE-like connectors I have mentioned and occupies three out of four connectors available. The HDD is attached to this daughter-board from below, while the CD-ROM drive – from above:
Watch the attachment sequence! The screws that fasten the HDD are then covered by the optical drive. The process of installation is quite easy. You only have to use non-standard screws, and there are a couple of spare screws coming with the computer, just in case, so you should be OK for a while.
Now, let’s get back to the topic why notebook drives are not a good solution here.
Firstly, such drives are expensive, costing much more than their desktop counterparts. For example, a 2.5” HDD of 40GB storage capacity costs now over $100, while desktop HDDs of the same capacity are almost twice as cheap. Slim CD-ROM drives are even more expensive.
However, the high price is not the only negative factor. “Notebook” drives are also slower. For example, we now have two spindle rotation speeds in the desktop HDD field: 5,400rpm and 7,200rpm. And 5,400rpm drives are slowly dying out. For “notebook” drives, 4,200rpm spindle rotation speed is standard, while 5,400rpm products are considered a kind of hi-end. The following table lists technical characteristics of some 2.5” and 3.5” hard disk drives. Go ahead and compare them, to see what I am driving at:
We will now see what those characteristics mean in practice. We will carry out a brief test session of the hard disk drive subsystem. The Iwill ZPC is the first participant, and the second one was configured as follows:
- Iwill MPX2 mainboard on the AMD 760MPX chipset;
- Two Athlon MP 2200+ processors;
- 512MB Hyundai DDR266 SDRAM (PC2100);
- Seagate Barracuda 7200.7 HDD, 40GB.
The dual-processor nature of the second system is not important at all in this case. But the mainboard is made by the same manufacturer :). So, I ran Ziff Davis WinBench99 and got the following Disk Transfer Rate result for the ZPC with the Toshiba 2.5” HDD:
Now, you will see the graph of the ordinary “desktop” Barracuda. By the way, this graph describes the transfer rate for the middle 30GB of the disk, not for the entire disk surface. That is, 5GB are cut off in the beginning and in the end. Thus, the Transfer Rate should be higher in the beginning, and lower in the end of the disk. Moreover, the drive was used to about 80% of its capacity. The results are obvious enough, though: