Packet table and chunk caching to increase write speed


Does H5Pset_cache affect packet table write performance or I must open
the packet table as dataset and set its access propertylist
(H5Pset_chunk_cache) to have them cached?
I have about 150 packet tables of INT16 type and I set the chunk size
to (1024*1024) I assumed it is in bytes in H5PTcreate_fl.
According to the document 64 * 1024 * 1024 can fit 64 of my chunks
and thus 6863 is the first prime number greater than 100*64

Right now I only set caching on the file level and I do not see much

    double rdcc_w0 = 1; // We only write so this should work according
to the document
    int mdc_nelmts = 0; // What is the best value
    hid_t facpl = H5Pcreate(H5P_FILE_ACCESS);
    ret = H5Pset_cache(facpl, mdc_nelmts, 6863, 64 * 1024 * 1024,
rdcc_w0); // 64MB cache
    hid_t file;
    file = H5Fcreate(szDstFile, H5F_ACC_TRUNC, H5P_DEFAULT, facpl);
    ret = H5Pclose(facpl);

Thanks for any hints