How reliable is the MTBF for 811S

vbimport

#1

It is rated at 70,000 MTBF POH and 2% write cycle. I don't know about you guys, but I think this is a low figure. Not that I'm complaining as those drives are affordable to start with, but according to some calculations I've made it comes out to about 120 full length DVDs.

Should I really be concerned ? Has anybody burnt more than 120 full length DVDs ? Or have any comments :slight_smile:

Thanks
.


#2

I have burned near 300 dvds on my 411s for data and movies, and its still going strong. Maybe i’m lucky. Don’t want to jinks myself though.


#3

Originally posted by Rimmer66
[B]It is rated at 70,000 MTBF POH and 2% write cycle. I don’t know about you guys, but I think this is a low figure. Not that I’m complaining as those drives are affordable to start with, but according to some calculations I’ve made it comes out to about 120 full length DVDs.

Should I really be concerned ? Has anybody burnt more than 120 full length DVDs ? Or have any comments :slight_smile:

Thanks
. [/B]

70,000 hours = 2916 days = 8 years

I don’t know about you but 8 years is more then sufficient for me…


#4

Yeah, I’m with Beefy on this one. I think that the MTBF is more of a “should last this long” rating V.S. a real indication as to how long it will last. I myself have burned litrally thousands of CD’s and DVD’s and have never actually had a drive fail.:stuck_out_tongue:


#5

Originally posted by Ssseth
[B]70,000 hours = 2916 days = 8 years

I don’t know about you but 8 years is more then sufficient for me… [/B]

Actually you should be aware that the 70,000 MTBF refers strictly to POH (Power ON hours). During duty cycle it’s usually 2-10% of the MTBF. So if you plan on using your LiteON drive as an exposition item or a relic, maybe it will last you more than 8 years :slight_smile: However the LiteON specs indicate 2% duty cycle for write operations, so the more realistic MTBF would be 2% of 70,000. :slight_smile:


#6

Originally posted by Rimmer66
Actually you should be aware that the 70,000 MTBF refers strictly to POH (Power ON hours). During duty cycle it’s usually 2-10% of the MTBF. So if you plan on using your LiteON drive as an exposition item or a relic, maybe it will last you more than 8 years :slight_smile: However the LiteON specs indicate 2% duty cycle for write operations, so the more realistic MTBF would be 2% of 70,000. :slight_smile:

(700000,0260min/hour) / (9min/dvd) = 9333 full length discs.
This should be enough…thats 3,2 discs pr day for 8 years


#7

Originally posted by lyhnet
B / (9min/dvd) = 9333 full length discs.
This should be enough…thats 3,2 discs pr day for 8 years [/B]

My thought exactly. I think Rimmer forgot that MTBF is in hour. Beside, my PC is not on 24 hours, it should help a bit right? :slight_smile:

In 1-2 years, better technology will come along. Now i don’t even care about my 1st gen DVD-ROM anymore. Come to think of it, I should have used it more back then. :slight_smile:


#8

Originally posted by simplelife
[B]My thought exactly. I think Rimmer forgot that MTBF is in hour. Beside, my PC is not on 24 hours, it should help a bit right? :slight_smile:

In 1-2 years, better technology will come along. Now i don’t even care about my 1st gen DVD-ROM anymore. Come to think of it, I should have used it more back then. :slight_smile: [/B]

:smiley: Come on give me credit, I know better that MTBF 70,000 was in hours not seconds :slight_smile:

Seriously, I don’t know how you calculated over 9000 DVDs, :slight_smile:

But here’s how I calculated it and you can correct me if I’m wrong:

70,000 MTBF POH ( estimate on actual POWER ON HOURS, non operation mode)

Duty write cycle 2% of MTBF…

2% of 70,000 = 1400 HOURS of estimated write cycle before failure.

Writing a DVD Video at 4x completes on an average of 15 minutes (rounded figure). (this example involves a FULLY recorded DVD)

1400 HOURS / 15 minutes = 93 FULL LENGTH DVDs (rounded figure) Now this is not 100% accurate representation given the fact not all DVDs will be burnt full capacity, so I can add an extra margin, maybe doubling to 180-200 DVDs…

Quite a far cry from your over 9000 DVDs. :slight_smile: :slight_smile: :slight_smile:


#9

Rimmer66,
your caculations are flawed…You are

you are divding hours/ minutes

1400 HOURS / 15 minutes
.

This is not correct as its like dividing apples / oranges.
You need to covert either the 1400 hours into minutes (1400 * 60 = 84000) or convert the 15 minutes into a fraction of an hour (15/60 = 0.25)

So

84000 minutes / 15 minutes = 5600 FULL LENGTH DVDs
1400 hours / 0.25 hours = 5600 FULL LENGTH DVDs

PeebZ


#10

Originally posted by Rimmer66
[B]:smiley: Come on give me credit, I know better that MTBF 70,000 was in hours not seconds :slight_smile:

Seriously, I don’t know how you calculated over 9000 DVDs, :slight_smile:

But here’s how I calculated it and you can correct me if I’m wrong:

70,000 MTBF POH ( estimate on actual POWER ON HOURS, non operation mode)

Duty write cycle 2% of MTBF…

2% of 70,000 = 1400 HOURS of estimated write cycle before failure.

Writing a DVD Video at 4x completes on an average of 15 minutes (rounded figure). (this example involves a FULLY recorded DVD)

1400 HOURS / 15 minutes = 93 FULL LENGTH DVDs (rounded figure) Now this is not 100% accurate representation given the fact not all DVDs will be burnt full capacity, so I can add an extra margin, maybe doubling to 180-200 DVDs…

Quite a far cry from your over 9000 DVDs. :slight_smile: :slight_smile: :slight_smile: [/B]

Im sure you never attended math classes :cop: … dividing hours with minutes pr disc gives no resonable unit…try converting the hours to minuts og visa versa, and you might get af better result. (BTW. I estimated that a full dvd will take 9min - 8x recording)

:rolleyes:


#11

Originally posted by Rimmer66
70,000 MTBF POH ( estimate on actual POWER ON HOURS, non operation mode)

Duty write cycle 2% of MTBF…

2% of 70,000 = 1400 HOURS of estimated write cycle before failure.

Writing a DVD Video at 4x completes on an average of 15 minutes (rounded figure). (this example involves a FULLY recorded DVD.)

It’s correct upto here.

If assume that the DVD takes 15 minutes to burn (at 4x), so you can burn 4 discs in 1 hour. Right?

1400*4 = 5600 Discs

If assume that the DVD takes 9 minutes to burn (at 8x), so you can burn 6.67 discs in 1 hour. Right?

1400*6.67 = 9330 Discs

By the way, you are probably the first one that actually try to determine MTBF. This number come out from some calculations. Thus, does not really effect the real world usage anyway.

It’s good to look at but i just never believe it. I’ll be happy already if this things will last me with my normal burning rate for 1-2 year. :bigsmile:


#12

I had already figured out the discs. I thought he was concerned with the total life (power on) of the drive.

Also that is assuming you get the min 2%. They said 2%-10. So the avg would be about 6% or 15,000 discs or so :smiley: I don’t know about you but I don’t think I’ll even come close to the 5,000! :eek:


#13

Originally posted by lyhnet
[B]Im sure you never attended math classes :cop: … dividing hours with minutes pr disc gives no resonable unit…try converting the hours to minuts og visa versa, and you might get af better result. (BTW. I estimated that a full dvd will take 9min - 8x recording)

:rolleyes: [/B]

<embarassed> It was very late when I wrote this or I was really tired… I did attend math :slight_smile: But how could I have done such a stupid mistake. True I forgot to convert those minutes into hours. BTW 15 minutes is a 1/4 of an hour, so I can simply multiply those 15 minutes by 4.

MTBF 70,000 POH
Write cycle @ 2% POH = 1400 hours
Average burn for a full length DVD @ 4x = 15 minutes.
AVERAGE burning of 4 DVDs per 1 hour (average, may vary)
1400 hours * 4 DVDs = 5600 DVDs

1400 hours = 84,000 minutes

84,000 minutes / 15 minutes = 5600

So it’s true I was wrong about the calculation. However it’s still far from the initial 9000+ :slight_smile:

This is really an estimate and any drives can fail much sooner. I’ve known cases of people who have burnt well over 300 DVDs with no problem, AND also cases where some people’s drives burnt (no pun intended) after 20.

Somehow I think one would have to be lucky to burn 5600 DVDs, mind you that’s just an opinion. :slight_smile:

Anyways those 12x and 16x DVD burners will come out in the future so I’ve read on your site. So by the time I reach that amount it will be obsolete.


#14

Originally posted by simplelife
[B]It’s correct upto here.

If assume that the DVD takes 15 minutes to burn (at 4x), so you can burn 4 discs in 1 hour. Right?

1400*4 = 5600 Discs

If assume that the DVD takes 9 minutes to burn (at 8x), so you can burn 6.67 discs in 1 hour. Right?

1400*6.67 = 9330 Discs

By the way, you are probably the first one that actually try to determine MTBF. This number come out from some calculations. Thus, does not really effect the real world usage anyway.

It’s good to look at but i just never believe it. I’ll be happy already if this things will last me with my normal burning rate for 1-2 year. :bigsmile: [/B]

I’m fully aware about MTBF and I know it’s based on a CALCULATION and results will vary. This is why I wrote this thread to see what people think, as there are different opinions. Still it’s always good to know some drives have higher numbers than others…

As to burning media at 8x, is it really safe ? You’ll have to forgive me as I am completly new to DVD burning. I would have no problem burning DATA at 8x but is it really safe to burn a DVD Video at 8x ? Will it have an impact on PIPO scans and playback on a DVD player ?


#15

Safe? Yes. It’s designed to burn at 8X.

Affect Kprobe scans? Probably slightly higher PI, but on good media still within acceptable limits.

Affect playback? Probably not, but see above.

I’m running a 401S@411S@811S and my Kprobe scans have always been good to average, allowing for variations between firmware.