Optimal cache block size?

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insertrealname
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Optimal cache block size?

Post by insertrealname »

What are the considerations concerning optimal cache size with respect to the size of data transfers to and from the physical disk? I'm assuming that the Windows driver layer below FancyCache will probably read or write much larger segments of data than the cache block, and that FancyCache batches read/writes to this layer for efficiency. So, are there any guidelines that may minimize the amount of rewriting and reorganizing that FancyCache must do?

Does the Windows Superfetch service go through the cache, or bypass it? I haven't seen any justification for disabling it, simply because if Superfetch requests go through the cache, then Fancycache is being pre-filled with data that have a high probability of being used.

I have set a 64K block size, 2GB cache, in the FancyCache disk version, with a 7200.4 Seagate disk, for the last week. So far, my subjective impression is that programs with continuous intense disk I/O activity do benefit, e.g. the Internet cloud backup application I use, which reads/writes a local metadata state database intensively as well as creating binary diff segments to upload, runs faster and (surprisingly) with less CPU peaking.
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Re: Optimal cache block size?

Post by Support »

Hi,

Generally smaller cache block size brings higher performance however increases cache overhead. The program gives a recommended value according to the capacity of volume/disk. This value doesn't affect the efficiency of the lower Windows driver layer. It affects the cache hit rate.
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