I have a 1Tb SSD setup as a cache drive to my media but the performance is not great, in fact it is a bottle neck now I have fibre.

I am getting about 37MB/s to the cache drive when I tx a large 80GB file from my Windows PC to the cache drive, if I transfer the same file to a different drive on the array as a drive share on the array I was getting approx 77MB/s.

Writing directly to the array gives me about 30MB/s

I can see the SSD bursts up to 350+MB/s but then just falls to next to nothing, any ideas what is going wrong here?

(this a Dell R730XP, Dual Xeon with 256GB of RAM, Perc 730)

tower-diagnostics-20260101-2320.zip

Edited January 2Jan 2 by ridley
Clarification

8 hours ago, ridley said:

I can see the SSD bursts up to 350+MB/s but t

Do you see the busts during the transfer or just the WebGUI stats? Post a screenshot of the Windows File Explorer graph while transferring a large file.

6 hours ago, JorgeB said:

Do you see the busts during the transfer or just the WebGUI stats? Post a screenshot of the Windows File Explorer graph while transferring a large file.

This is a transfer directly to the ssd cache drive "Cache_main"

It goes at full speed for about 5 minutes and then it starts doing this.

I meant the Windows Explorer graph, like this:

1 hour ago, JorgeB said:

I meant the Windows Explorer graph, like this:

That suggests to me the LAN is OK, the device cannot keep up with the writes, note that most SSDs use a pseudo SLC cache that can vary in size from model to model, and also depending on how full the device is. When that is exhausted, the writes are limited by the actual TLC (or QLC) NAND speed, also considering that it looks like the SSD doesn't have a brand, so possibly it's just that slow once the cache is exhausted.