Romex Software Forum

computer is i7 w 16 gig ram, 256 gig ssd, 2 internal hds
windows 7 pro, fancycache 0.8 beta
pc mostly used for video editing

from my reading it seems a good configuration for the C: drive is 16kb block size, 2 gig L1 cache size, algorithm LFU-R, Cache strategy Read/write
Enable defer write on, latency 90 sec, uncheck overcome HDD C1 issue, leave all other boxes unchecked

for the other internal hds a larger block size and a larger cache might be better (since larger files are being pushed around) 64kb block, 4 gig L1 cache? dont know how to decide on whether to use LFU-R or LRU, cahcing strategy R/W
Enable defer write on, latency 90 sec, leave 'overcome HDD C1' checked, all other boxes unchecked

any suggestions? when would I want to 'release after write'?
when would I want to 'average write amount'?
other suggestions on latency?

I've found that a lot of these settings are going to be dependent on your particular hardware config. You'll really want to do a bunch of benchmarking to find the sweet spot for your setup.

My advice is increment up the block size while using Anvil pro to simulated non-sequential disk writes, test against compressible data like application data and noncompressable like zips, avi, etc (found under the Anvil settings). Your level 1 cache should be as large as you can make it without starving the applications you'll be running. So you'll want to use perfmon to log memory while you run your apps to get an idea of what your peak memory usage is, give yourself about a 20% buffer (or more) above that and set the rest to be your Level 1 cache. The larger your RAM cache the less you'll hit your hard drives.

I'm using LFU-R because it makes most sense to me to drop the least frequently used over the dropping the oldest. Just because data is old (in memory) doesn't necessarily mean it's not going to be used more frequently. Of course this is all based on instinct and past experience. My testing didn't show any significant difference between the two. Enabling Over Come HDD C1 had a big impact on my setup but its easy to test, do one benchmark with it on and one with it off and you'll see for yourself how it affects your performance.

I've found that release after write and average write changed for me from config to config. Sometimes it helped and others it hurt. I'd test those last.

Latency makes a pretty big difference in what you'll see performance wise BUT it comes with a major problem. If you lose power or blue screen anything held in that buffer could be corrupted. So the bigger the buffer the more you are exposed. There's no across the board answer on this one. I wouldn't use it for anything that you can't have damaged, so running it on the C drive might be a bit risky but if you are willing to restore from backup if things break it might be worth the extra speed. I'd recommend a SSD for C and leave write caching off for that drive. I have a drive that I use to compress and decompress large files (10-50GB) and that's a perfect use for write caching in my opinion.

tnx. i appreciate the depth of your reply --the truth is never simple.