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Questions:why cache size limit? limited dl speeds? and torrent users?


John123

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I started using utorrent four days ago. Nothing I have done over the last four days has affected either my dl rates or ul rates. Of course dl and ul rate can be reduced. I have gone through and applied the mini guide and read or skimmed many on the posting over the last 4 days (If my questions have been answered…. Just point me to it).

Sys

· Windows XP service pack 2

· 2 GB RAM

· 7200 RPM HD

· dl speed is 3840 KiB/s (dedicated)

· ul speed is 576 KiB/s (slowest speed I have measured)

Question 1: Occasionally when I am doing other things on the computer I get the "Disk Overloaded" Error. I understand why I am getting the error (to many read/write commands going to the HD), but why is it a bad thing to set "diskio.write_queue_size =" and "diskio.read_cache_size =", "higher than 32768 (32 MB)"?

Question 2: I cannot achieve fast (1MBps) dl speeds. What might be my problem?

· dl speed in utorrent has been 400kBps (+/- 50 kBps), max at 491kBps

· ul speed in utorrent solid at 500kBps (Global maximum upload rate (kB/s) = 500kBps), max at 601kBps

· Port check comes back "green" every time.

· Changed settings specified by mini guide (no noticeable effect in transfer dl or ul rates)

· Most Important……..Max dl speed has not been directly tied to the number of torrents I have open (tried 4, 10, and 15 open at a time). To me this means there is significant bandwidth available for faster dl. ----- My ISP said they do not limit... dl speed 3840 Kbps is dedicated to whatever I do. When I dl from Microsoft and other large (backbone connected) software companies I can regularly dl large (10s of MB) files at 2-3 MBps.

Question 3: This is a simple question but I have not found a definitive answer…. Are all torrent users (sharers) 'connected' to all the torrent programs (utorrent, Azureus, ect…)? If 'yes' great. If 'no' are there networks (TV, movies, games, ect.) of users who use certain torrent programs over others and is a directory of this info online?

Tks

Use edit next time.

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1) The read cache *should* be set to a high number, definitely higher than 32MB. As for the write cache... as you approach 32MB, marginal utility (lol too much Economics for me) decreases. Setting it to a higher number might help, but probably not by much more.

2) Torrents are like that. They don't guarantee speed, but file distribution (with decent speeds coming as a side effect). Your speeds seem respectable enough, as it's difficult to find peers that upload quickly enough to max out your fat pipe.

3) Check splintax's beginner's guide to BitTorrent. Each torrent is basically its own kind of network, and you're connected to whoever's on the torrent as well, whatever their client is. One unique torrent is separate from another unique torrent, and it's not your traditional P2P network in that sense either.

As for the mistake, you can just edit your previous post.

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Thanks Ultima, your responses on 1 and 3 were great. Tested 1 by running three separate searches on the computer at the same time and it didn't kill utorrent speeds for almost a minute (previously one search caused utorrent to stop after ~10 seconds).

But on question 2 my "Max dl speed has not been directly tied to the number of torrents I have open (tried 4, 10, and 15 open at a time). " I understand there is limited uploading bandwidth out there.

If I am dl from 4 torrents [60-80 seeds each and 200-400 peers each] at ~400KBps…..Then add 4 more torrents [60-80 seeds each and 200-400 peers each] (with a totally different subject... thereby assuming mostly different seed hosts and peers, from the first 4 torrents) to the dl list.

I would expect to see increase in total dl speed because the average 400kBps is ~11% of the total dl bandwidth capability. But no increase in dl speed?

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Nope, like I said, torrents are like that, and they don't always max out your connection. The adding seeds, peers, and active torrents don't necessarily increase your speed. It's all about the quality of the peers you are currently connected to. When you added those torrents, download speed didn't budge at all?

Try a faster torrent, like OpenOffice.org v2.0.2 w/ JRE torrent.

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Ultima – "When you added those torrents, download speed didn't budge at all?" That is correct there was no change at all in dl speeds…. After you responded at 02:07:02 I started thinking about your previous comments on question 2 "Torrents are like that. They don't guarantee speed, but file distribution (with decent speeds coming as a side effect). Your speeds seem respectable enough, as it's difficult to find peers that upload quickly enough to max out your fat pipe."…

Because not many people have dl 30MB/s and upload 5MB/s capability yet, my problem may not be very common and I would have to find my own dl speed solutions. After 4 more hours of tweaking and adjusting, the solutions to my problem became clear (these solutions may be applicable to everyone with fat pipes and might be added as an appendix to the mini guide).

First, let me note that initially I made all of the changes suggested in the mini guide and saw no results.

· dl speed in utorrent has been 400kB/s (+/- 50 kB/s), max at 491kB/s

· upload speed in utorrent solid at 500kB/s (Global maximum upload rate (kB/s) = 500kB/s)

After the final adjustments (below) I made to the system the mini guide changes my have helped (I am not going to go back and undo them all just to see:).

Adjustments/Settings Results:

· dl speed in utorrent has been 1050kB/s (+/- 150 kB/s), max at 1394kB/s

· upload speed in utorrent solid at 375kB/s (Global maximum upload rate (kB/s) = 375kB/s)

With 15 torrents [2-80 seeds each and 5-400 peers each]

BTW – When I started downloading "OpenOffice.org v2.0.2 w/ JRE" suggested by Ultima my dl speed jumped to 2300kB/s (+/- 150 kB/s), max at 2611kB/s. And took ~40 seconds to dl the 104MB "OpenOffice.org v2.0.2 w/ JRE" file.

Suggested Adjustments/Settings (for Fat Pipe Users with Newer Computers):

BUFFERING: Important

Raised the Read cache to 512 MB RAM. "disk.read_cache_size = 524288" When the HD becomes tied up the dl rate will go to 0KB/s as new TCPIP data packets can not be saved to the HD when the Read cache is full (the default setting of "disk.read_cache_size = -1" auto adjustment is NOT fine for fast dl rates and ppl who use there computer for more than downloading). In my case downloading at 1MB/s bought me +1 minute of downloading while I purposely tied up the primary HD channel.

Set the Write queue to 16 MB RAM "diskio.write_queue_size = 16384" Why not raise the write queue to support others dl? When the HD becomes tied up the upload rate will go to 0KB/s as new TCPIP requests cannot be processed/accessed fast enough (nothing can really be done to help this, the system doesn't know what data it needs to send until a P2P request is received therefore system can not queue until the P2P request is received. This setting is virtually useless when upload at very high speeds)

UPLOAD SLOTS LIMITING: Very Important

No matter how fast your computer is (mine ~3.5 GHz), how much RAM (2 GB RAM), how many connections you 'allow' your system to handle (4000), or how fat your pipes are (dl 30MB/s and upload 5MB/s)… there is a limit to the number of TCPIP packets your system can process. In my case 8%-15% of all the data I send and receive is overhead/garbage needed for TCPIP, limiting this garbage is critical.

With 15 torrents (5 seeds and 10 leaches) and "Global maximum upload rate (kB/s) = 375kB/s" (more on this setting below) I can provide a solid 375 kB/s to the community with just 3 (45 total leachers with 8.33 kB/s each) upload slots per torrent… 2 upload slots (30 total leachers with 12.50 kB/s each) per torrent is not enough for stable output…. 4-7 upload slots (+60 total leachers with 6.25 kB/s each) per torrent only showed a minor stability improvement over 3 (45 total leachers with 8.33 kB/s each) upload slots per torrent. At +8 upload slots (+120 total leachers with 3.13 kB/s each) per torrent my average dl speeds started to suffer. Over 1 hour of watching the upload and dl speed graph I saw a direct correlation between dl speeds and # of upload slots. Why is this true…. I'm not sure, my Wild Ass Guess (WAG) is attributable to excess connection garbage. I personally have no problem limiting upload slots because my Global maximum upload rate is always max at 375 kB/s. PS Yes, I did play with how many connections I 'allow' my system to handle (currently set to 4000) and it didn't effect transfer rates until I dropped it so low (~900) that dl and up connections were dropped.

UPLOAD SPEED LIMITING: Very Important

As I stated in the previous section limiting garbage connections appears to be necessary. So why do we need to also limit our upload speed limit?

My WAG on this is two fold: 1 the more upload bandwidth, the more incoming TCPIP packet requests are received and 'clog' the system 'garbage': 2 TCPIP may limit the out going dl packet requests if there is limited processor speed available (ie too many input packets block out going packets).

I can't tell you what upload speed is right for you….. I settled on 375 kB/s (65% of my min upload capability) by watching the dl speed average. During testing dl rate change was very dramatic (1050 kB/s to 380 kB/s) when I changed the upload rate from 375 kB/s (65% of my min upload capability) to 500 kB/s (86% of my min upload capability)…. I tried this separate 5 times over 30 minutes because of how dramatic/bad the change was. Again, I personally have no problem limiting upload speed because I believe in seeding!! And no (ppl w fat pipes) you don't have to stop downloading because of HD space, the seeded files can reside on a separate HD and just raise their "Bandwidth Allocation" priority to high and they will seed to 200% in no time.

Finally, FYI to everyone with and without fat pipes. During testing, when I set my upload rate to just 10KB/s I was only able to dl at 35KB/s (ie everyone must upload to dl). If this has helped you great….. please help us all by seeding. Tks

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  • 1 month later...
  • 1 month later...

Well, it all seems like voodoo to me, I tried a bunch of shit, while watching the speed graph, including some of the above (some of which settings don't seem available in my version 1.6). I have 10Megabit up/ 10Megabit down FTTH (Fiber to the Home). My speeds would oscillate wildly between 300 KBytes/sec and 800 (averaging only 400). FWIW Azureus had the same problem. Back to uTorrent, I am not sure what fixed me, but when I started seeding 2 torrents instead of 1, it seemed to stabilize at my 720KB/sec up I set it to. I'm not doing any downloads, so the write cache stuff is irrelevant. I still get some burps but they are minor. OK I am going out to buy some more chicken blood and sprinkle it on my motherboard, that is likely what fixed it.

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I should learn to keep still, anyway, I stopped the 2nd torrent, and again the first torrent speed started gyrating wildly up and down. Turned the 2nd torrent back on and things may be slowly stabilizing again. No idea how to rationally explain this.

I'm goin' down to Louisiana, get me a mojo hand. And some of those Santeria candles.

Would be interesting if uTorrent had a "dump all settings into a text file" button so we could post our settings and compare notes.

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bgmnt: the settings of John123 are now included in the "disk-cache settings".

for 10MBit up/down and good hardware i would suggest: speed guide for utorrent settings

disk-cache (can be found in Settings > Advanced > Disk Cache): min. 256MB Cache Size (depends on your RAM)

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Under Preferences > Advanced > Disk Cache, there is "Override automatic cache size" which lets me specify the size manually. BUT, this is only for the WRITE cache. You can confirm this by going to the bottom panel, the Speed tab, and then Show: Disk Statistics. Changing that setting only affects the Write Cache. I am not doing any writing, I am only trying to read and to seed.

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Turning off the write cache would be bad for whenever you DID download. Plus, when there's no downloading going on, it puts everything towards read caching anyway (if applicable).

When I go the bottom panel, the Speed tab, and then Show: Disk Statistics, it does not look to me that "it puts everything towards read caching". That is, under Write Statitics, it shows the larger cache, but shows it as empty, and under Read Statistics, nothing changes.

Interestingly, the gyrations always occur regularly at one minute intervals. The graph is almost like a heart monitor. Every minute the speed dips, then shoots up and overshoots, then glides back down to the upload speed I set (720KB/sec on 10mbit upstream fiber). I've turned off most of the extra programs on this machine; is uTorrent doing garbage collection at one minute intervals or something? And maybe this is not a big deal with slow connections, but with 10mbit upstream, a lot of garbage (or some kind of minute-by-minute internal housekeeping) piles up, enough to burp the flow of packets?

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I did turn that off lately. Appreciate your patience. Its not saying Disk Overloaded. My efforts have indeed had zero effect. I can still report that the oscillations have a period of 60 seconds. I am set to 1000KB/sec up and it gyrates between 750 and 1100 every minute. Anyone have any idea why, throughout everything I've done over the last day or two, the only constant thing is: 1 minute long cycle. The only thing that helped smooth stuff out was to seed a second torrent at the same time. OK now I set it to 900KB/sec up and the range is 800 to 1000. All I can guess is that few people have 10 megabit upstream and uTorrent has never been fully tested to adapt to this situation. Again, Azureus seems to have similar problems.

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With all due respect to the mods and the coders, and the uTorrent team (I love the flags), I don't understand why my 10/10 mbit FTTH gyrates in speed so wildly. I guess I'd like to set it to 900 or 800 or even 700 and have it stay there on a flat line, rather than go from 400 to 1000 and back and forth every minute. When it "tested very well" did it (mis-)behave like this? Anyone have any idea why its a 60 second cycle?

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I have a 15/2 and my download speeds stay consistently ~1.4MB/s, upload is consistently at 220KB/s. Obviously it depends on the swarm, but I almost exclusively download from private trackers, so the seeder to leecher ratio is very high, and the seeders are all highspeed.

Does this happen to you on all torrents?

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If you're looking for wild guess, here's one:

Older versions of Windows (9x/ME) does a CD/floppy/removable drive check to see if there's disks in the drives every minute or so. This was doubly bad when coupled with CD autoboot enabled and a bootable CD inserted. Win XP may have a similar cpu-eating feature.

SL83, I'd think on private torrents with very many high-speed seeders and few peers that there would be times your upload speed would drop due to either lack of peers requesting pieces of the torrents from you or those peers' connections are overloaded. Not a bug or problem on your end, but a possible occurance anyway.

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I'm on XP. I can get up to 800KBytes/sec up, but rarely get over 200KB/sec down. Maybe I'm using the wrong private trackers. So, it does happen to me on all torrents, but most of my torrents are from the same private tracker, so I can't say yet. If the RSS stuff in uTorrent were more turnkey (like in Azureus) I'd probably be able to answer the question.

Actually the upload speed gyrates wildly between 300 and 1000. eMule doesn't have this problem; I can set 800K up and it may only fluctuate a few percent (but if I push it beyone 800 it starts flailing).

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  • 1 month later...

Guys this may look stupid to you but as I have absolutely no knowledge of torrents.I have this question:

John123 has written:Port check comes back "green" every time. As I am behind proxy I have asked admin if my ports are blocked or not.He answered that my ports(all) are not blocked.That's why I am surprised why my port check is always yellow(or orange-strange color) and utorrent message is that there's some network problem...I have read all posts here and many of them help me raised dl speed more than 10kB but as my internet ul speed is 512kB(bytes) and dl 3064kB it pisses me off when my dl speed is 23kB and ul speed is 240kB and when I look at some peer he is downloading from me with 50kB speed but is giving me only 2kB. I think this is NOT fair. I will appreciate any reasonable advice.THX.

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not when I set limit to upload speed it will cause my DL drop down even more...when I let my upload unlimited DL will increase to "famous" 23kB...I was set that difference between my DL and UL is because my access is WI-FI half duplex the bandwith is not strictly divided between DL and UL like in DSL where there's strictly bordered DL and UL for e.g. 2048DL/512UL. So I will welcome any advices which could help me find reasonable solution,even when I think that there's not any.I was told that when I don't have a public IP will never be able to use torrent client fairly...Anyway thanks for any advice.

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  • 2 weeks later...

Can you post all the settings you're using as they're shown in Speed Guide (CTRL+G)?

Also what half-open limit are you using?

...there may still be a setting or 2 holding your speeds down.

(Either that or you're still firewalled and/or on slow torrents with very few fast connections.)

If you're firewalled, it's not that you're "never be able to use torrent client fairly" -- but that firewalled connections CANNOT connect to each other. So you and everyone else that is firewalled can neither upload nor download from each other. If there's lots or mostly firewalled peers and seeds...your speeds will suffer too.

Many proxys are set up vaguely like unforwarded routers, so whoever's on them is always firewalled. The ports aren't blocked in the sense that you cannot connect to others on them...they just cannot "out-of-the-blue" connect to you. Being firewalled is like having a telephone that doesn't ring. ...and connecting to someone else who is firewalled means they'll never answer because they never hear their "phone" ring either.

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