Thread: Why does my entire PC lockup for 10 seconds when DVD or CD is loading?

Maybe antivirus program is scanning?

Damn well might be SafeROM or some other anti-piracy measure reading the CD and locking the PC up.

That's an off-the-hip educated guess, take it with a grain of salt until further researched. (Which I don't have time to do at the moment, but it seems likely to me.)

Originally Posted by Veovis

While my optical drive is accessing the disc, whatever I am doing (web browsing, using NOTEPAD, etc) locks up.

This has to do with the way the computer handles and processes requests for information, and it's been around for forever-and-a-half.

The computer by default only updates the mount status of a removable drive when requested, which means that while you're not doing anything to access the drive or cause an update (such as opening My Computer / opening Explorer / using a Save or Open dialog), the computer won't spin up the drive, and in order to save power and reduce noise and wear and tear on the drive, won't keep a disc spun for very long.

The 'lock-up' comes when data or a mount update is requested of the drive. IDE drives work through the IDE controller, which handles data into and off of the drive, and uses an IRQ, or interrupt request, to make the PCI bus pay attention to it so that it can tranceive data to the rest of the computer*. Since the bus is dedicated for the interrupt window to the drive, nothing else can occur while the drive does its work (preventing a data collision in the bus). Unfortunately, this often means the drive has to spin up first, which takes a number of seconds due to drive mechanics.

In short, it's a "fault" in the way the PCI architecture is designed, and there's no fix for it as it's a feature not a bug!

Draco

* The PCI bus in a computer acts like a intermediate connection between peripheral cards and I/O (such as the IDE bus) and the north bridge, which contains the memory controller and pathways to the CPU. In order to handle multiple devices, the system works on a FIFO (first-in, first-out) interrupt request system, that makes the bus dedicate itself for a particular block of time to a particular device, so that it can transmit or receive data. This way, each device receives or sends the data it should, and the processor thread gets the data it wanted in a more efficient fashion (since the PCI bandwidth is fully available, it can be transferred much faster, and data integrity is maintained between devices). However, it also means that slower devices (like a disc drive that has to get a CD/DVD up to speed before it can read the data) can grab the bus for very long periods of time, because once they have a fufilled interrupt request they have sole influence over the bus; think of it like a big official meeting where the PCI bus is the chairman, and the devices are all the speakers; only one person gets to talk at a time, and they get to have all the time they want once the chairman recognizes them to speak.

And that's why your computer freezes a bit while the drive spins up, and more than you ever wanted to know on how computers are designed.

Originally Posted by Veovis

Or, I guess with some drives it happens for longer than others, and maybe mine is just particularly long.

I've noticed that my Lite-On drives do tend to take a bit longer than other brands to spin (but they're damned good, reliable cheap drives, so 'meh'). Keep in mind too that combo drives have to figure out what kind of disc is loaded when they spin up; they first check for a CD with a longer-wavelength laser, and then if the data comes through corrupt, switch up to the shorter-wavelength DVD laser, which can also add a bit of time to the spin-up.

Draco

Turn off autoplay on your cd-rom drive. It may cut it down on the time.