USER RESPONSIBLE FOR VERIFYING VERSION AND COMPLETENESS
OEM FUNCTIONAL SPECIFICATION ULTRASTAR XP (DFHC) SSA MODELS 1.12/2.25 GB -1.0" HIGH
6.7 *Mean Time Between Failure (*MTBF)
The mean time to failure target is 1,000,000 device hours per fail (3.0% CDF) based on the following
assumptions:
6000 power on hours per year (500 power on hours per month times 12 months)
300 average on/off cycles per year (25 power cycles per month times 12 months)
Seeking/Reading/Writing is assumed to be 2 0% of power on hours (Approximately 10read/write oper-
ations per second)
Operating at or below the Reliability temperature specifications (See Table 15 on page 78) and nominal
voltages (See 2.2, “Power Requirements by Model” on page 15)
Note: *MTBF - is a measure of the failure characteristics over total product life. *MTBF includes normal
integration induced, installation, early life (latent), and intrinsic failures. *MTBF ispredicatedon supplier
qualification, product design verification test, and field performance data.

6.7.1 Sample Failure Rate Projections

The following tables are for reference only. The tables contain failure rate projections for a given set of user
conditions. Similar projections will be provided, upon request, for each user specific power on hour and
power cyclesper month condition. Contact your I BM customer representative for a customized projection.
Table 13. Projected failure rates for the electronics only.
Table 14. Projected failure rates for the entire drive. (Electronics and HDA).
6.8 SPQL (Shipped product quality level)6.9 Install Defect Free
Application Electronics only - (RA/MM)
1st 30
days
1st 60
days
1st 90
days
30 day
average
over
life
CDF
500POH/MM 0.00120 0.0010 0.00096 0.00036 2.1%
730POH/MM 0.00160 0.00140 0.00125 0.00047 2.8%
Application Electronics and HDA - (RA/MM)
1st 30
days
1st 60
days
1st 90
days
30 day
average
over
life
CDF
500POH/MM 0.00150 0.00130 0.00120 0.00050 3.0%
730POH/MM 0.00200 0.00170 0.00160 0.00070 4.1%
LA vintage Ultimate(13th month)
Targets .25% .10%
Source filename=POH IBM Corporation Page 75 of 87