Romex Software Forum

I've been running many different versions of Primocache over the years, and I've always used standard settings for the Device Manager Drive Policies. Specifically, "Enable write caching on the device (checked)", and "Turn off Windows wrote-cache buffer flushing on the device (unchecked)".

I'm familiar with what both do, but wanted to ask the question: is there any reason to enable or disable either feature such that Primocache runs more compatibly or more efficiently with Windows and the drive(s)? i.e. is turning on write-cache buffer flushing redundant and unnecessary if you already use Primocache's write caching? Would it be better to have both policies turned off, for maximum compatibility, or does that negatively affect performance? A UPS is already supporting the system, so that's a non-issue.

Hi Jaga,

I would just leave the Windows default write cache alone since Primocache already have two stages defer write. Adding another write buffer, in ram, is not going to make any different for performance and overhead. You can already define how much and how long to keep the data in cache with Primocache.

What Primocache need is to fix the problem with prefetch, add the option to first flush all L1 to L2 cache (including interval time control and retaining the write data for future read ) before flushing to the hard disk, and possible read-ahead feature (similar to superspeed supercache v.3).

I pretty sure these features will enhance performance of Primocache even further.

minhgi wrote:Adding another write buffer, in ram, is not going to make any different for performance and overhead.

I agree, it probably won't affect performance by enabling the write-cache buffer flushing, but it *might* help drive thrashing due to the way that feature changes how Windows writes data to drives. Primocache has to write that data back to the drive later at some point (even when using the write cache), and I didn't know if it had it's own special algorithms to do the writing, or if it relied on Windows standard write routines.

Just looking for information and clarity that might help with optimal tuning of the system. For now I'm leaving them on defaults. Other systems (like my Media PC) that don't currently have Primocache installed on them have both enabled, and drive thrashing seems to be greatly improved there.

We usually test the program with Windows default drive settings. PrimoCache has its own writing mechanism and does not rely on Windows writing policy.

Great, so we can safely ignore those settings and seeing any impact when using the write cache. Thanks Support.