Does extra hard drive cache make a difference for streaming video?
I am looking at the following two drives for a RAID device, which will be streaming normal things but also a lot of video:
- Seagate Constellation ES.3 ST4000NM0033 - hard drive - 4 TB - SATA-600
- TOSHIBA DT01ACA300 3TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5"
Will the 128 MB cache on the Seagate have an effect in my described scenario, compared to the 64 MB on the Toshiba? If so, what sort of difference can I expect?
I'm using a qnap device, if that matters.
72 Answers
From what I understand, a hard drive cache is used for stashing frequently accessed information in a fast solid state buffer (cache) on the drive so when that particular data is requested again the drive can pull it out of cache- a much faster process than getting it from the mechanical part of the drive. If you are streaming movies (or video) there probably won't be any performance advantage with a larger cache, since the same data won't be accessed repeatedly. Having said that, all things being equal, there is no downside purchasing a drive with a larger cache, and it might help with some of the smaller 'normal' files you refer to.
3No, the cache stores bits of data from files. SSHD hybrids store complete files and retrieves commonly accessed complete files while a cache has an algorithm that stores the front of commonly accessed files to make the hard drive read faster. In other words the cache stores bits of files not whole files. Thus it will make a difference for performance where same files are pulled consistently.
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