Warning W5205 - The write index/performance seems low. While (generally) the sustained read performance will be higher than the write performance, the write performance (on uncompressed drives) should be comparable, e.g. not ┬╜ or less than read performance.
Fix: Some SCSI hard drives/controllers may have write verify on; this feature checks that the data written matches the data on the disk by reading and comparing it. While this function is very important for data integrity, the performance hit is large.
More commonly the write cache may be off (i.e. write through mode). This is done to protect the data in case of power/system failure by making sure it is always written to disk synchronously. Again, this feature causes a performance hit so enable only if necessary.
NB. If your drive is compressed (e.g. by setting ΓÇ£Compress drive to safe disk spaceΓÇ¥) this warning is generally issued unless the system is very fast and able to compress the data very quickly; generally the hit is enough to cause the write speed low as decompression is much faster. This is by design.
For more information, please see the (FAQ).