IBM contacted Storage Review and essentially said they and anybody else were all wet when it came to talking about 60GXP and 120GXP reliability.
Well, we looked closer at some hard drive documents, and it actually raises a few more questions.
We went to IBM’s functional specifications going back to the 14GXP. You can take a look at them yourself:
14GXP, page 48
22GXP, page 56
34GXP, page 54
75GXP, page 53
60GXP, page 50
120GXP, page 50
All of them say essentially the same thing for the reliability statistics:
“The drive withstands a minimum of 40,000 start/stop cycle under a 40C environment and a minimum of 10,000 start/stop cycle under any other extreme temperature of humidity environment within the operating range.”
This doesn’t mean a whole lot because a start/stop cycle boils down to “turn the computer on/turn it off.”
Starting with the 60GXP, the following language began to be included:
Expected product life is 5 years under typical desktop PC usage conditions:
– 333 Power-On Hours (POH) per month
– Seeking/writing/reading operation to be 20% of POH at 40C or lower environmental temperature
This essentially is a different way of measuring how long these things should last before things start wearing out. Do the math, and it comes out to about 20K hours.
Is This Any Better Or Worse Than Anybody Else?
Unfortunately, the major manufacturers don’t have really comparable statistics. IBM doesn’t use MTBF ratings, which don’t mean what most think they mean, and can’t be used or converted to an equivalent of IBM’s service life.
Western Digital doesn’t use service life. Maxtor does, and states the same five year period, but doesn’t state the conditions of the five year period like IBM does.
Before anybody can compare relative reliabilities between the two, they need to find out from Maxtor exactly what the conditions of their five year period are.
Putting Your Money Where Your Mouth Is
I can sell you a used car and tell you it’s going to last for three years. I could tell you it could last for three centuries, too; saying that just costs me two extra syllables.
As PCGuide wisely points out, the promise you should pay attention to is the one that costs the company money if not kept.
IBM basically has a three year warranty. Did so before, does so now. Although IBM hard drives do keep track of the hours it is used, p.177, the IBM spokesperson said that hours used have no bearing on warranty policy, and any hard drive manufacturer certainly has reason to make such a measurement. How else could they determine real-life reliability?
Maxtor and Western Digital have three year warranties, too.
So no matter what statistic you have, all three essentially say their drives are good for up to 25K hours (3 years X 8,760 hours per year, or 26,280 hours for the AR), or they’ll replace it.
Conclusions
We suggest to Storage Review (since they have the ongoing relationships with the hard drive companies) that they might wish to do the following:
1) As mentioned above, contact Maxtor to see what their five year service life is made out of and perhaps ask Western Digital if they have
2) Ask IBM whether or not the 20K hours one gets from multiplying their recommended power on hours is (outside of the three year warranty period) a reasonable basis for those who use IBM drives (whether current or not) for periods exceeding those used in IBM’s calculations to determine service life.
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