BLER (Block Error Rate) is defined as the number of data blocks per second that contain detectable errors, at the input of the C1 decoder. Since this is the most general measurement of the quality of a disc, you will find BLER graphs for all media tested below. If you click on the images, you can see a more detailed table, indicating error levels.

The Red Book specification (IEC 908) calls for a maximum BLER of 220 per second, averaged over ten seconds. Discs with higher BLER are likely to produce uncorrectable errors. Al low BLER shows that the system as a whole is performing well, and the pit geometry is good. However, BLER only tells us how many errors were generated per second, and it does not tell us anything about the severity of those errors.

Memorex CD-R 52X

Click for the full graph

Click for the full graph

Memorex Pro Gold CD-R 52X

Click for the full graph

Click for the full graph

From the graphs, there is no real, visible difference. The data blocks per second that contain detectable errors (BLER) however, appear to be more, especially for 52X CD-R media. The Pro Gold series, appears to restrict the error rate from increasing.