4 ms·
Most recent tape standards have multiple "bands" and "wraps" placed in parallel. The head reads only one wrap at a time, so it takes many passes to read the who
by texse 6y ago
Most recent tape standards have multiple "bands" and "wraps" placed in parallel. The head reads only one wrap at a time, so it takes many passes to read the whole tape. For example an LTO-8 tape has 52 wraps each within 4 bands, requiring 208 passes to read completely.
- TedDoesntTalk 6y agoWhy not just have multiple heads then?
- nine_k 6y agoPositioning the tape should become harder, I suppose. Also, I suppose they limit the read bandwidth with something like what a single Infiniband connection would support; few disk arrays support much higher speeds.
- paulmd 6y agoIt would be like downloading a file using GetRight back in the day, where you'd have one thread downloading the 0-25% chunk, one downloading the 25-50% chunk, and so on. You could hypothetically do that, for sure, but the software basically is derived from the tape era where you'd just have one logical stream coming out of the tape.
- Dylan16807 6y agoThere are. The tradeoff of speed vs. complexity is currently sitting at 32 heads.