No, no need to. Windows write caching sits at the file system level, while PrimoCache Defer-Write sits at the disk sector level, so Windows write caching will process write requests before PrimoCache. Once Windows has stored the data in its cache, it notifies the application that the write request has completed, and the application can then proceed. Windows will then convert the cached data into corresponding disk sector write instructions after a certain delay and send them to PrimoCache for further processing. If Windows write caching is turned off, the application
will not be notified of completion of the write request until PrimoCache receives disk sector write instructions from Windows. At this time, for the application, the write response time will become longer, and accordingly, the write performance will not be as good as the former.
So what are the advantages of PrimoCache Defer-Write compared with Windows write caching?
- Windows write caching uses a fixed latency of 2 seconds and does not have any parameters for user adjustment. PrimoCache can flexibly configure various parameters such as latency and writing mode as needed.
- Windows can only use RAM as the cache medium, while PrimoCache can use RAM and SSD as the cache medium.
- Because PrimoCache operates at the disk sector level and processes disk sectors directly, it can more efficiently consolidate random writes into sequential writes, resulting in better write performance.
- Applications can bypass Windows write caching, but not PrimoCache because PrimoCache operates at the disk sector level.
- Windows cache space is shared by all logical volumes, so any read or write operation on any logical volume may cause the entire cache space to fill up with data, requiring the previous cached data to be flushed to the hard disk urgently. In addition, Windows uses currently available free memory as the cache, so its capacity changes dynamically. If applications request more memory, Windows cache space has to be reduced accordingly, causing the cached data in this space to be released as well. Therefore, its caching behavior is more uncontrollable, and accordingly, its caching effect is more unpredictable. PrimoCache can be set to cache only the required logical volumes. With the same cache capacity, the latter will be more targeted and the cache effect will be better. Moreover, the cache space is pre-allocated, and the cached data will not be released when applications ask for more memory.