Random Access   chris, kp & rob
In The Lab
Letters From The Mailbag
by chris

Micro Center In-Store Clinics this month include "Backups and Archiving" and "Hard Drives and RAID " Is it just coincidence that we received some emails from our readers asking about drive technology? Probably, but read on anyway...

"What's the difference between SATA drives and PATA drives?"
- Vaughan
"How can I connect a SATA drive to a PC with an EIDE interface? Can a PC support both EIDE and SATA?"
- Max

The basic difference is in how data is transferred, Serial ATA (SATA) drives use a serial (1-bit at a time) data transfer method while Parallel ATA (PATA) drives use a parallel data transfer (multiple data lines to send and receive data). Both drives use similar drive mechanisms and control electronics, and only differ in how the data is transferred between the computer and the drive. To further confuse things, ATA drives may be identified as IDE, EIDE, ATAPI and even as UDMA (Ultra DMA) drives; Wikipedia has lots more to say in their AT Attachment entry and documents the historical timeline well. With the introduction of the Serial ATA standard, the original ATA standard was "renamed" to PATA to distinguish between the two. More significant than the serial or parallel data transfer is the maximum rate at which data can be transferred. The best transfer speed PATA UDMA drives reach is around 133MB/s, which just happens to also be the maximum PCI bus speed that the interface is connected to. Compare this to the first SATA drives that had a maximum transfer rate of 150MB/s. We already have the second generation SATA drives and interfaces that can support maximum transfer rates up to 300 MB/s.

Most of the current generation systems I have examined have both PATA (IDE) and SATA drive connections on the motherboard. The current trend seems to be away from the PATA connections, and many manufacturers have changed from two connectors (primary and secondary) to a single IDE connection. While most of the optical drives on the market are still PATA, we are just now starting to see an increase in the number and selection of SATA optical drives. With two PATA interfaces, hard drives are typically attached to the primary connector and optical drives to the secondary connector. Since you can have up to two drives on a single PATA connection (configured as master and slave), it means you can still have a single hard drive and a single optical drive on the cable, but no way to expand beyond this without installing a PATA controller in the system. With SATA drives, only a single device is attached to each SATA connector, and no jumper configuration is necessary.

Older systems may not have SATA connections on the system board. So what do you do if you want to connect or install a SATA drive in the computer? In most cases, you would approach this just like adding support for USB2, FireWire, enhanced graphics or additional network capabilities, and add SATA support by installing an interface card in an empty expansion slot. One reason for using an interface card on newer systems would be to add enhanced capabilities such as RAID or E-SATA (External SATA).

If all of your slots are full, you can install a single SATA drive on an open PATA connection using an IDE to SATA "Bridge" such as the one by StarTech. If you just need to connect a drive to transfer data off of it, something like the SATA / IDE USB Adapter by Vantec simplifies the process to make a temporary connection. For more permanent connections, you can get an external mounting kit designed for your drive type and interface. There are 3.5" SATA or PATA kits available as well as 2.5" drive kits for installing those old notebook drives.

"Which mp3 players can bookmark audio books? Is there a URL that keeps track of this since it is clearly a moving target?"
- Art

For a relevant answer, I would probably need more information about the audio books you want to work with. What type of audio books are we talking about here and what format are they in? If these are ripped from CDs, then the format could be whatever your default is, such as MP3, AA3, WMA, etc. So if you are recording audio books to the computer from audio cassette or ripping from CD, the file format is only limited by the program you use to rip or record with. If the audio book is in the same format as your music files, then being able to set and jump to audio bookmarks would have to be a feature of your MP3 device or media player application. One of the audio book distributors I am most familiar with is Audible.Com. Audible uses a "Download Manager" program to download, archive, and transfer files to the playback device. On some devices Audible uses an AudiblePlayer application or they may just install a codec that can be used by the standard media player programs. I could play audio books on my Windows CE PDA by using their add-in to the media player, but I found that Microsoft Reader also could be used to play the same files back. Media Player could not bookmark files, but Reader can. (Microsoft Reader is still a free download application for Desktop, Laptop, Tablet PCs, or Pocket PC / Windows Mobile devices and phones. Go to http://www.microsoft.com/reader/ and click on "Downloads" in the side navigation bar.) Later versions of the Audible Manager added the ability to burn to an "audio" CD (you would then have to RIP the audio CD to create MP3 or other multimedia format files. I tried this only once; before I could play back the book, I had to rename and organize the files, since they had not so meaningful file names like "track1", "track2", "track3", and so on). I usually went for unabridged books, several of which were 8-10 hours or more in length. Figure an hour per CD, and at least 10 tracks on each CD, and I think you may begin to see how this is a real pain to even try to deal with using this approach. The proprietary AudiblePlayer format is compressed like an MP3 file, but it can still run as much as 14MB or more for the highest quality (Audible compression format 4) playback. Most of the portable devices can only handle CD or Radio quality files (Audible compression formats 2 & 3).

What playback device to use? I was checking out "AudibleReady" Devices on Audible.com and found the expected players like iPod, Creative Zen, iRiver and Rio devices. Their list has grown to include just about any Palm, Pocket PC, Windows Mobile PDAs and phones. What I was surprised to find were GPS Navigation devices like the TomTom Go 910 and the Garmin Street Pilot! In the Audible Support section, I did a search on "bookmark" which returned 15 documents, some of which include the same devices. I did not find a single document that details features like setting a bookmark. Scanning each of the search result documents, I did find some of what you appear to be looking for. For example, IPod shuffle documentation mentions setting a bookmark automatically by pressing "stop" before the battery dies. If the power fails during playback, you will have to start playback from the beginning. Other entries indicate that a device bookmark feature may only support the paused position, and cannot be changed or reset until you play through to the end of the book.

Here is a summary of what I found looking at their search results:

  • Audible Manager does support setting multiple bookmarks, but that will only help if you listen on your PC or laptop, not an MP3 player.
  • Creative MuVo does NOT support bookmarks.
  • iPods support bookmarks only if the file is in a .aa or .m4p format, not MP3; bookmarks are set automatically when pressing pause or stop and will resume play at the same spot. This is not the same as creating a bookmark to come back to at a later time after playing different files.
  • PocketPC and Windows Mobile support bookmarks in the AudiblePlayer application (and if Microsoft Reader still plays these files back it can bookmark places as well.)
  • Garmin Nüvi supports bookmarks in playback mode.
  • Second generation Dell DJ players can bookmark Audible files using the .aa format (save & resume only)
  • SanDisk Sansa C100 may have bookmark features in the future.
  • iRiver T10 and T30 support bookmarks
  • Creative Zen-Sleek does support bookmarks
  • SanDisk DAP will save your last position (pause or stop), but not bookmarks as such.

"Can you explain if DDR memory can go to the next clock speed. Can I use a 3200 chip on a 2700 (333 MHZ) board? And how far up the chain can I go if they support the slow speeds?"
- Kiwi

Technically a system that specifies PC-2700 DDR RAM should be able to handle faster PC-3200 memory with no problems. DDR is a form of Synchronous DRAM, simply meaning that access to the memory is synchronized with a clock pulse (in this case, the one on the memory bus). The PC specification (PC-2700 and PC-3200) is calculated by taking the transfer width of the memory bus (8 bytes) and multiplying it by the clock speed of the memory bus. This means that PC-2700 memory is designed to transfer eight bytes of data based on a clock that "ticks" 337 million times each second (337 MHz; 337.5 x 8=2700), and that PC-3200 DDR memory is designed to transfer data based on bus clock speeds up to 400 MHz.

However, the bus speed is not the only value that may be critical in terms of access; there are timing delays that occur after each operation used to access a specific memory location. The different delays are specified as a number that represents the number of clock ticks that occur between the start of a specific step and the time it takes for the circuit to respond or complete the tasks. Latency values are not always critical for compatibility in every system. However, in some systems you may have to meet or beat certain latency timing values to be able to use a specific memory module. For example, you could turn up two different modules of DDR PC-3200 memory that have very different prices; one reason for this may be the latency values for the modules. A CL3 DIMM is usually going to cost more than a CL4 module, because it should respond faster. Both modules are going to be designed for the same clock speed of the memory bus but there will be a shorter delay before the CPU can access the contents of the CL3 RAM.

Unfortunately, there are a couple of things that could prevent your system from using the faster module. The first is how your computer is designed to detect the memory speed. The most common method is to read the specifications from the memory module during the system's Power On Self Test process. The specifications are typically stored in non-volatile memory on the memory module (SPD). The BIOS of your computer can then adjust system timing to match the access rates pulled from the memory modules it finds; but what happens if the values are out of range? If the largest number your system expects is 2700 and if reads a value of 3200, how should it proceed? Some manufacturers will initiate a quick timing test to verify how fast the module can respond. But if this approach is not supported, your system could simply refuse to boot with that particular memory installed or you may get a "beep" code error. In this case, you alternatives would be to hunt down slower memory that is compatible with the system or see if there is a BIOS update that.

Memory vendor websites have some excellent reference material available to explain what these numbers mean and why they are important or can affect the overall performance. For example, Corsair has a series of memory buying guides with links to their "Ram Guy" Technical Guides. Kingston Technology has their Ultimate Memory Guide, and Centon has a series of FAQ pages that may be able to address this, or related questions.

"My computer had hard drive damage; I changed it out, but I want to know how I can install the Windows XP, because it told me that I can't install from drive C:"
- Eduardo

If you installed an old drive that had a previous installation of Windows XP on it, it is very unlikely that either the prior install will support the different system hardware, or that all of the necessary install files are present on the drive. One of the first steps of the Windows XP installer is to copy the cabinet archive files to an i386 directory on the hard drive; if this folder exists, and you were running the setup from there, it is probably complaining that it cannot copy files to the same directory as the source of the files. If you formatted the drive by booting from the Windows XP CD, then it should have gone on to copy the files and then reboot at least once to configure and install the operating system after restarting from the hard drive.

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