Laser power at different burning speeds

[Greycat]

It's a simple question I guess: is the power used by
DVD burners' laser the same no matter the burning speed,
or the higher the speed, the higher the laser power?

If the answer is "same power no matter the speed",
then I presume I'm right assuming that burning at
higher speeds (8x, 16x) will make the laser head of my
burner last longer than burning at lower speeds (4x).

My question is because I prefer burning at 4x since
this speed is more reliable than 8x and 16x (unless you
only use very good media, not so easy to find around here).
But if this practice decreases the laser lifespan, then
I'll burn at higher speeds right away!

[redwudz]

My understanding is the burner circuitry adjusts laser power depending on the burn speed. It first burns a test sample in an area of the inner ring reserved for that, then error checks it. If it's OK, then the usable speeds are set. A typical laser should last about 10,000 hours, so I wouldn't really worry about it failing because of using higher powers during the machines lifetime.

Some media may have problems burning at a lower speed when both the media and burner are designed for the higher speeds. If you have errors burning at the rated speed of the media and the burner, I would get better media or a better burner.

[Greycat]

redwuz:

A typical laser should last about 10,000 hours, so I wouldn't really worry about it failing because of using higher powers during the machines lifetime.

Many people in this forum (me included) found out that their burners lasted just for 100-200 burns, let's say 150 average. If for example we burned only single-layer DVDR's at 4x (14 minutes or 0.23 hour each burn) then our lasers lasted 0.23 x 150 = 34 hours of real usage, very distant of those 10,000 hours -- unless the drive's idle time counts too, which means that its laser was full-powered all the time, and that sounds very insane

So, I personally really won't trust on those manufacturer's numbers until a DVD burner gives me (theoretically) 10,000 / 0.23 = 43,478 burns (at 4x)...

But, returning to my first question, I still don't know if the power used to burn at 8x (for instance) is twice (for instance) the power used for 4x, or is just aprox. the same (for the same media brand!)

[ark]

The MTBF given by the manufacturer gives an idea of the avarage life of the burner. It goes into over 50,000 hours for most of the burners. This is irrespective of the speed at which you are burning.
I have used my DVR-107B to burn more than 1000 disks till now, it is still going strong. My normal burn speed is 4, sometimes I do at 8 speed. The error is much less for lower speed burning - based on my personal experience. I suspect it has to do with the balance of the disk, the associated centrifugal forces creating wobling and corresponding effort required by the burner's laser sled to follow the track accurately.

[Skith]

Keep in mind that heat can be an issue as well. If you are using your burner to burn discs at 4x, 6x, 8x, or whatever speed, no-stop for hours at a time, you are likely to put more stress on your drive/laser as it heats up. Allowing it to cool for 10-15 min. after a number of burns may be a good idea.

As for what a drive can tolerate, that would depend on it's design, and component quality (or so I would suspect), as well as case ventilation.

***I am not an expert at electronics or engineering and this is all information I have come across, feel free to correct me if any of this is wrong.

[redwudz]

I believe the power of the laser would increase as the speed of the burn increases. I have no idea if it is a linear increase. The laser manufacturer rates the lifetime of a laser diode. How it is used is not up to them. That said, you will find many users here that have gotten many more than 100-200 burns. 1000 or more would be a more realistic figure. Normally, the rest of the drive mechanism should wear out before the laser fails. That is the more common cause of burner mechanical failures. Lasers fail, no doubt, but if they are properly constructed and not allowed to overheat beyond their designs, they shouldn't be the normal cause of burner failure.

You can try to dig into this failure problem further, but most companies don't want to discuss it and theoretical information doesn't always apply to real life. I can only say from experience that laser failure is not often the cause of burner failure if the system is designed properly.

[OneSickPup]

I know drives fall victim to design defects and manufacturing defects. But I'm convinced that the primary cause for optical drive failure is environmental. Skith is correct that heat is a huge factor in drive longevity. The better the case ventilation - the more likely a long usable life cycle. Adequate power is another factor. Too many drives fall victim to aging or under-sized power supplies. And last but not least - air quality. Dust, smoke and other contaminants/pollutants can reek havoc even when heat and power are eliminated as factors.

I have purchased 10 dvd writers in the last 3 years - 1 Sony, 2 Benq, 2 Pioneer, 2 Liteon, 2 LG and 1 Nec. Only one drive died due to a defect. The other 9 are all functioning in some capacity or another. One drive has over 1000 burns to its credit. I'm no expert - just a hobbyist with a passion for experimenting with different drives - firmwares and media. But I honestly would not think the burnspeed has much to do with a burners life expectancy. Just my 2 cents.

[samijubal]

I've done somewhere around 4000 burns on an NEC 3500, it still works like day one. Most of those were ripped on the same burner. I do about 3-4 rips and burns, then I let it cool for half an hour or so and do 3-4 more. Get a good quality burner and you shouldn't have to worry about it.

[garryheather]

Laser power will also be affected by the write strategy in general - two different manufacturers of say 4x discs may require completely different strategies so it's difficult to say. I'd say the off-on-off action of the laser during the burn itself would be the biggest stress on the assembly, personally.

[Greycat]

Well, if a lot of people here say their burners gave 2,000 to 4,000 or more ripping/burns and are still working, then I am definitely an unlucky guy. My LG 4160B burner gave me just 100 or so burns in just 10 months! (aprox. 1 burn every 3 days!). After that, all discs I burned can't be read after the 50% mark, or are just not recognized. First I thought it was bad media, but I tested several brands (including the ones that never failed before) and all failed. Looking at the surface of a disc burned at 4x, it is dark in the beginning (center) and becomes progressively brighter to the end (edge) as if the laser lost its power throughout the burning process. Same thing for reading a DVD: it can read just about 50% of a disc. (BTW, the CD laser is Ok since I never used it, so now I have a nice CD burner for the price of a DVD burner... )

Worst of all, I didn't even use it for ripping DVDs or burning/reading CDs (I use a combo driver to do that). If you live in a place where DVD burners are not expensive, it's not a big problem: you just buy a brand new one and make a pile of the old ones as a hobby. But unhappily it's not my case -- any computer device here cost 2 or 3 times more than in USA or Europe, and if their durability is a matter of luck or lottery, it's a big problem.

As I said before, maybe I'm just an unlucky guy (although I'm not alone, just search in this forum). Well, let's see if my new LG 4167B can last more than 1 year or 100 burns so I can consider myself a little luckier.

Thanx for all for the replies.

[hech54]

My old LG4040B is still going strong. It is a 4x only burner...no bitsetting and no D/L support....so that should tell you how old it is. I really have no idea (nor do I care) how many hours of burning time I have on it because just like scanning burned DVD's for errors and such....it is a complete waste of time.
I suspect my new 4167B will be just as faithful.