wishlist - ultra 2/4/6 with sandybridge and hdmi

TeknoJnky wrote:
viewtopic.php?f=19&t=51208 under all circumstances (i.e. even for doing a Windows directory copy that contains lots of smaller files). The Ultra 4 can only manage about 14 MB/s I think its highly dependant on the disks.

Interesting to see your performance results in the thread you referenced however I notice that although these numbers exceed 100MB/s you are mostly copying large files (movies, music) and also you seem to be measuring the aggregate performance across multiple concurrent reads. Is that correct? I would expect that if you did the same test with a single user process copying thousands of 4K files you would get much lower than 100MB/s.

For example, if you look a the results for the WD20EARS drives that you use in your NAS, the 4K read/write performance is less than 1MB/s! Here is the worst-case performance of a single disk. You should get higher performance with 4 disks in RAID-5 but not 4 times the performance:


So, I think there is a lot of potential performance benefit by adding an SSD cache like the Vertex 3 that can approach 70MB/s for a 4K read (which is over 100 times better performance than possible with a WD20EARS drive).

and 200MB/s for a 4K write: