Bandwidth and RAM.

I always wondered why Upload Bandwidth on Torrent takes up so much RAM? I never notice a huge Bandwidth increase when downloading, but torrents are being Uploaded I notice huge RAM increase. Not a problem, just want have an idea of why this is.

 

I've noticed that too (using Azureus), don't know what's causing it though. As soon as i stop the torrent from uploading memory usage decreases again, more then 200mb per torrent sometimes (it seems to make a difference how long the torrnt has been uploading).

 

I don't down/up load that much but,this sounds like a question for the CS guys.It would be interesting to find out why this happens.

 

High memory usage by Azureus is due to the fact that it's java-based client.
There's no such thing with uTorrent.
It also depends on your settings (cache, max number of connections etc.)and can be limited in a way but only to a certain level.
Plus you gotta remember the faster connection you have (upload) the more "upload slots" are available by default, so more people are connected/tracked and the program uses more RAM.
EDIT:
Still RAM usage during download should be higher, unless you've got symmetric connection. Upload puts higher load on HD but that'd different thing.
What client do you use?

 

I use Azureus, but I don't think High Uploads affect it because it's Java. The same thing use to happen on Bittorrent with I used it. I would usually have two torrents downloading & Uploading at once and cap uploads on each at 20kb.

 

High RAM usage with Azureus is caused by java- not exactly when uploading but in general. Compare it with uTorrent if you wanna see the difference. (EDIT: Yeah, I wrote that once already :/) What's your maximum number of connections? - that's what usually causes high RAM usage with Azuresus.
BTW how many MB are we talking about?

 

Yea, I already know about regular Azureus usage of ram use compare to other clients, but I'm talking about the Bandwidth usage increase when Uploading occurs.

I usually don't see and increase in ram until I'm Downloading & Uploading 2 torrents at the same time. Then it can jump to using 100mb or more ram. The same thing use to happen to me with Bittorrent so Java is not the reason here.

I might try uTorrent and see if it does the same.

 

Azureus probably caches all the individual chunks in memory when uploading, it doesn't re-read the file from the disk every time. You're seeing increased memory usage almost certainly because of that. uTorrent may not do the same kind of thing, but it may have performance trade-offs because of that, such as a lot of disk usage.

 

That makes sense.

 

Actually it's not like that at all. Easy enough to ONLY upload a file and go to Azureus Tools/Statistics/Cache.
You can upload with your full speed and cache in use will still show 0B, you can also see that all I/O reads come from disc, not cache.
Cache cannot actually work for uploading- it's easy to make one write operation after certain number of MB is gathered to lower disc usage but you would have to cache the entire file for uploading as you don't know what part of it will be requested by peer.

 

So what do you think is causing the increase RAM?

 

I’m not sure but my guess is – high number of tracked connections. Is your RAM usage higher when you are only uploading one torrent than when your only downloading one torrent?

 

Actually I notice higher when I'm Downloading 2 torrents and it Upload at the same time. I put 20KB limit most of the time. Sometimes I might have only one torrents with no limit on upload bandwidth, when it's gets around 30-40kbs, that when I notice the jump in RAM.

I could be downloading 5 torrents at a time and have little upload traffic. RAM would be normal.