How does a cluster size affect the readyboost function? The default cluster size is 2^12 bytes. What about higher order? I think of 2^13 bytes or 2^14 bytes? What is better ExFat or NTFS for ReadyBoost?
I started testing cluster size and I found that for my 8Gb thumb drive the best format was Exfat at 4096Kb. I tested with DiskMark. Speedgain at 8192Kb was negligible but there was gain over 2048Kb cluster size.
Sequential Read (Q= 32,T= 1) : 19.295 MB/s
Sequential Write (Q= 32,T= 1) : 7.864 MB/s
Random Read 4KiB (Q= 32,T= 1) : 5.673 MB/s [ 1385.0 IOPS]
Random Write 4KiB (Q= 32,T= 1) : 0.015 MB/s [ 3.7 IOPS]
Sequential Read (T= 1) : 19.084 MB/s
Sequential Write (T= 1) : 7.968 MB/s
Random Read 4KiB (Q= 1,T= 1) : 5.321 MB/s [ 1299.1 IOPS]
Random Write 4KiB (Q= 1,T= 1) : 0.010 MB/s
If you whant to get the advantages of ReadyBoost on Windows 7, you have to do the following:
- Format the external disk with exFAT, with cluster size 1024kb.
- Go to drive Properties (right click on the drive letter) and select ReadyBoost Tab.
- Select Dedicate this drive to ReadyBoost. Apply.
- Go to Customize Tab and Optimize for General Items. Apply and Ok.
Then the system will create the ReadyBoost file.
If you run virtual machines, configure their preferences to "allow some VM swap memory".
Cluster size does not really matter for ReadyBoost: it uses one big file, and all writes and reads are done directly and aligned to the memory page size regardless of file cluster size.
The only thing that matters is that the start of the file is aligned to the sector size used for communication with the drive, so 4kB or a multiple of such for cluster size is recommended. This will almost always be the case anyway.