Disk read cache

[Roisen.dubh]

How do I change the disk read cache?

Overriding the automatic cache size in the disk cache settings under advanced only changed the write cache, and I can not find any options in advanced that apply to what I'm looking for.

Also, transfers via LAN are limited to ~400kBps. I am aware that there was a similar problem 2 years ago that could be found by searching, but the problem was never resolved. What could be bottlenecking transfers? (from Vista to Server 2003)

[jewelisheaven]

... Read cache is used as part of the cache, when needed. Use Speed tab, Disk Statistics view to see current cache usage.

If you want it to use the full RAM you specify, turn off the options to limit/remove/change in the Ctrl-P -> Advanced -> Disk Cache view.

The similar problem 2 years ago was before the current Disk Cache view was adopted. http://forum.utorrent.com/viewtopic.php?pid=175131#p175131

If you don't want LAN transfers to be limited by your peer settings turn off Ctrl-P -> BitTorrent -> limit local peer bandwidth.

[Roisen.dubh]

When I manually set the cache to 64MB, the disk statistics shows that my write cache is 0kB / 64MB, and my read cache is (initially) 1MB / 1MB. After ~20 minutes, my read cache will slowly increase to 24.0MB / 24.1MB, and that is just a very long spin-up time. Considering that I am only uploading to a single client right now, and later I will be uploading to 10+ clients...

Also, now that the read cache has finally leveled off at 24MB, my upload speed still hasn't increased

[jewelisheaven]

... OK? @ 4Mbit that hardly requires such a large cache. What settings do you have checked in Disk Cache now?

[Roisen.dubh]

Initially, I thought that the low read cache was choking my upload speeds, and I highly suspect that it was. Before the read cache leveled off, upload speeds were bouncing between 0 and 400kBps, but now they're pretty consistent at 400kBps. It would be nice if I could just set the read cache to a high level to begin with so that the cache won't have to slowly ramp up to 24MB and mildly choke speeds in the process. If there is no way to do this, then I guess I'm out of luck.

As for the speeds being capped to 400kBps on a gigabit network... I'll just start a new thread.

[jewelisheaven]

Thanks for not answering the questions.

It has to "ramp" up because it can't magically buffer XX MiB of data. You set the cache... you let the uploader start the cache. If either remove old blocks or turn off read cache if the upload speed is low is enabled you're likely to have to rebuffer the data. Also you should turn off reduce memory usage, if you want uT to "keep" your override local cache setting.

[Roisen.dubh]

Sorry, After I answered the first part of your question, I forgot that there was a second part.

checked options are:

Enable caching of disk writes

write out untouched blocks every 2 minutes

write out finished pieces immediately

enable caching of disk reads

remove old blocks from the cache

increase automatic cache size when cache thrashing

[jewelisheaven]

OK... so try it with the options I mentioned disabled. I pump out 5MBps on my 100BaseT LAN.... however I don't have to deal with the stupidity that is Vista So I can't help you other than suggesting what you already saw: Ultima's troubleshooting sticky.

[Roisen.dubh]

Thanks for helping, even though I obviously can't read. Could you possibly send me a copy of your settings file?

[jewelisheaven]

Pour Qui? My settings don't work for what you're trying to do. Mess with settings... test, re-test.

As far as... limits, I did find this gem: http://blogs.technet.com/markrussinovich/archive/2007/08/27/1833290.aspx

It's from the guy who makes the oft-used tool Process Explorer.

[Roisen.dubh]

You said that you could pump out 5MB on your LAN, perhaps you meant through explorer and not through utorrent?

[jewelisheaven]

5*8=40Mbit, nigh half my 100BaseT potential. Also you will want to check the OS isn't doing something stupid, like marking your HDD controllers @ PIO mode. They need to be in UDMA. I think UDMA-5 is 320Mbit, my SATAI drives are UDMA-6

[Roisen.dubh]

Agreed. But were you achieving 5MB speeds using utorrent, or 5MB speeds transferring through explorer (drag-n-drop). If you did that using utorrent, then you have achieved what I'm trying to do.

I'm unsure how to check this PIO mode, but the HDD that the file is on is capable of sustaining transfers at hundreds of times what it is now.

[jewelisheaven]

In XP it's System Properties, Hardware, Device Manager... or compmgmt.msc -> Device Manager

I presume it's something similar in those other OSes. I can hit just over 12 MBps in direct-copy and just over 11 over bittorrent. As I said check those options, then check the hub... Did you read my link to M. Russinovich's blog?