HP DAT 160 SCSI External Tape Drive Q1574A#AC3 产品宣传页

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Q7. What is the reliability specification of the DAT160 drive? 

The formal reliability specification for the DAT160 drive is 125,000 hours at 100% duty cycle.  

Note 

This is not a theoretical value or “specmanship.” It is derived from field 
failure rates for HP DAT products already in the field. The manufacturing 
release (MR) MTBF launch criteria shown in Figure 11 for the DAT160 
drive are the same as for previous HP DAT products at launch. Therefore, 
we can accurately predict that the DAT160 drive will achieve 125,000 
hours MTBF at 100% because we know other DAT products achieved that 
from the same starting point.  

For more information, refer to the July, 2004, “HP DAT40 and 72 MTBF specification change” white 
paper (

. 

Following is a summary from this white paper. 
HP provides an MTBF and bit ERT specification for its DDS products as a guide to the reliability that 

can be expected during customer use of these products. These specifications have, in the past, been 
generated using pre-production testing during the development of products. 
The existing specifications for the DDS products (pre 2004) were: 

MTBF: 400,000 hours at a 12% duty cycle 
Unrecoverable bit ERT: 1 in 1x10

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Based on field data gathered for the HP DDS-4 and DAT72 products, these specifications have now 

been revised to bring them inline with the reliability seen in the field by end users based on an 

assumed duty cycle. Therefore, this gives a much more representative measure of the real reliability of 

the product. 
The revised specifications are: 

MTBF: 125,000 hours at a 100% duty cycle 
Unrecoverable bit ERT: 1 in 1x10

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So HP changed its reliability metrics from being “predicted” from in-house testing before launch to 

being based on actual field data based on returns after the total return population. Given an actual 
measure achieved “in-house” at product release time, HP can accurately predict what the real-world 

reliability will be based on trend analysis from previous generations and millions of users. 
The test bed of release quality DAT160 products within HP has achieved 70,000 hours at 100% duty 

cycle.