Compaq HSZ80 manual External Cache Battery, ECB Capacity Based on Memory Size

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External Cache Battery

To preserve the write-back cache data in the event of a primary power failure, a cache module must be connected to an ECB or a UPS.

Compaq supplies two versions of ECBs: a single-battery ECB for single controller configurations, and a dual-battery ECB for dual-redundant controller configurations, which is shown in Figure 1–9.When the batteries are fully charged, an ECB can preserve 512 MB of cache memory for 24 hours. However, the battery capacity depends upon the size of memory contained in the cache module, which are listed in Table 1–10.

Table 1–10 ECB Capacity Based on Memory Size

Size	DIMM Combinations	Capacity
64 MB	Two, 32 MB each	96 hours
128 MB	Four, 32 MB each	48 hours
256 MB	Two, 128 MB each	48 hours
512 MB	Four, 128 MB each	24 hours

Compaq HSZ80 Array Controller ACS Version 8.3 Configuration and CLI Reference Guide