HArd Drive Thrashing

I've noticed that when I teleport to a new area, or fly very fast past a new area, My hard drive starts thrashing about. I know that it has to download anything new, but is it keeping a file cache somewhere of the new objects rather than in memory?

When I switch out to see how much memory the client is using, it only says 48 megs and my system is only using 400 of a total 1 gig. So I don't think the HD access is because of swap file use.

Are there any settings I can modify to remedy this? Or to tell the client to use more real memory and less swap?

You might try increasing the size of your cache.

And defragmenting your hard drive never hurts.

I kinda wish I could devote more than 1000 MB to the cache, because after about 2 minutes of flying about my computer starts to disk thrash horribly when loaading in new areas.

I have no problem allocating like 10 GB to the cache if it means i can flow through SL no problemo.

LF

Also running a second hard drive, with having the pageing file on the second hard drive will increase some performance, not to mention that it will save wear and tear on your C: drive.

That would be awesome.

SL appears to rebuild the cache each time you log, so having 10 gb wouldnt help you much.

Additionally, 10gb cache is a hard drive thing.

Your hard drive is thrashing because its being accessed. Its being accessed probably for the cache! You might want to try REDUCING the cache.

Also

It could also be your Page-File that is being thrashed. This happens when your computer doesnt have enough RAM to comply with what a program is asking for.

For example, if you use a 'large' texture cache (note - texture cache, not GB hardrive cache), sometimes I've seen SL ask for in excess of 1 GIG of RAM.

If you don't HAVE 1 GIG of ram, insane thrashing occurs.

SL has a permenant Cache file hidden in one of the most devious places I've ever found a hidden file. It increases by about 200 megs every time you play SL and will ultimately fill up your C: drive, although your C: drive will not know that it is filled up. It's DEVIOUS.

Does anyone know if this permanent cache is deleted when you uninstall SL? It better be

Its stored where application settings are stored.

C:\Documents and Settings\*USERNAME*\Application Data\SecondLife\cache

I thought it was cleared each time, but I wuz wrong.

You could try uninstalling and seeing where it goes ?

Could you be more specific about this devious location? If you are referring to:

C:\Documents and Settings\*USERNAME*\Application Data\SecondLife\cache

then that is pretty much the "standard" place for such things to go, although there is some question about whether each user of a particular PC needs their own cache. The naming convention, hokey though it may be is Microsoft's way of "innovating" from the age old Unix convention of /home/*user*/.... etc.

Man, I'm in a MEAN mood today!

Lots of hard drive activity while running Second Life is normal. Second Life contains a cache which contains cached textures, sounds, and objects, so you don't have to redownload them every time you log in. So while you're running SL, we're often fetching data off the disk, or saving data to the disk. So, it's not ALL memory swapping (yes, I know!).

To my knowledge, we shouldn't have any more issues with the data in the cache directory growing larger and larger - that data is now put into our fixed size cache file.

As a side note, this means that SL is simultaneously:

Running your CPU at full tilt (always).
Running your graphics card at full tilt (always).
Running your hard drive at fullt tilt (often).

These are the three biggest power drains in your average PC. Is YOUR power supply able to handle it? We've also successfully detected CPU, video card, and hard drive failures before they happen.

We also:
Generate lots of network IO traffic.
Generate lots of audio card traffic.

Is there anything else left on your average PC that we aren't using? I've been thinking that we should start marketing Second Life as a burn-in application for new computers.

- Doug

SL is the perfect answer for that hard drive that is almost out of date for a RMA burn up and send in heheh

Well, my CD-ROM has been pretty silent while running SL, as has the floppy drive, but that's about it.

While we are on the caching subject. Why is that I can be staring at an object and have its texture fully loaded, then teleport to another location with the exact same object (same texture UUID) and the texture still has to be downloaded (or isn't populated quickly)?

Another cache question: Why is it that I can teleport into a sim and zoom my camera on 1 object (filling the screen), and that object's textures aren't immediately loaded? It seems that textures in LOS would take priority. But I can easily sit and wait for upwards of 60 seconds sometimes for the texture to load. Stranger still, the bandwidth meter during these times is bottomed out (barely being used). That would make me think that the pipe at LL is choking.

I'm not losing packets and ping rates are reasonable usually.

Doug,
SL leaves a lot of files behind when it crashes, both in the temp folder and in the application data folder. These do not get wiped when we next run the client, and IMHO they should. I have ran out of disk space many times because of that.
As I understand it, SL's cache is a database neatly packed into a large file, so those 200 SLC files are definitely an anomaly.

Strange fact:

After just 10 minutes of travelling around the map, the 1000 MB cachefile has over 4,000 fragments.

This radically reduces speed.

I dont really know how they might fix this, but it means that after 30 minutes or so of playing, there are so many fragments in that cachefile that its faster to turn it OFF and just broadband everything (if you have that kind of connection).

Sapphire - downloading a texture (or reading it from the cache) is only the first of the three steps that have to happen before you can actually see it. Once you've got the encoded image data, SL needs to decode it into a usable texture, which is CPU-intensive and can take a while. When you teleport, some of the decoded texture data is probably being flushed. And, if you're looking at a big high-rez texture up close, it gets a high priority in the image queue, but the extra resolution means it might take 1000 times longer to decode than a typical small texture in the background.

Eggy - you're seeing the manifestation of a few bugs. We're working on it.

Mezzanine - send your complaints about this one to Microsoft. Using this large pre-allocated file is our only way to reduce fragmentation, and clearly it's not 100% (believe it or not it used to be worse). All I can say is, defrag your disk after you re-install and run SL.

Get a gig of RAM, you'll never thrash. Hell, I almost never thrashed with 512 unless my view distance was way far out.

512 MB and thrashing like mad with any significant movement.

I have to agree with Huns. I have 1 GB of ram, and I don't 'thrash' at all. Of course, my 4 x 120GB raid 5+0 array helps.

OMFG Maxx... are you single?

Its simple, I just wondered what I could do with a 0.36 TB storage device.

The answer - a hell of a lot.

Heh. Have I told you that I'm running SL on a 1-gig HD? Half of it is for win98SE, the other half for SL's cache
Vorgs grate. Except when I run out of disk space and SL crashes with out of memory errors

Another thing... if you are using an ultra-DMA drive, make sure it's on an 80-pin IDE connector (the usual ones are 40-pin). Put the fastest drive on its own channel so it doesn't have to slow down. Definitely don't put a UDMA drive on the same bus as a CD-ROM.