Ohhh ReadyNas

Please send in your logs (see the Sending Logs link in my sig)

Assuming the RND4000 was a NV+ v1, this was a unit that uses the same CPU and RAM as a product that was released back in February 2006. 

If it was the NV+ v2 it was released late 2011, it was still a cost effective storage solution.

The RN104 is a cost effective storage solution in our current range.

On both the ReadyNAS models you have had it wouldn't be advisable to run lots of apps, but rather just the few you want. If you want to run lots of apps at once then you'd be better off looking at the 200 series and above.

There are lots of apps available at places like apps.readynas.com, rnxtras.com etc.

How many files are in your directory that is taking several seconds to read? Which OS are you running on your client machine (e.g. Windows 7 Professional 64-bit)?

I would like to look at your logs to see if there are other things (than the disk issue) that may explain the poor performance you are referring to.

Note that if you use the anti-virus service you may wish to disable this for now. There is a known performance problem related to the use of AV at the moment.