Too many disk reads

[CyberTod]

Hello, I have a problem when I am seeding large files. The problem is that for example today from starting BitComet I have downloaded 1gb data and uploaded 5gb of data (approximately). When I start windows task manager and point to BitComet.exe and show column I/O Read bytes I have close to 600gb read from drive and the numbers increase by 60-80mb/s which is the physical limit for this drive. So my question is why when I am seeding with 200-300kb/s i have 60-80mb/s read from my drive ? I am posting below current configuration which is a new pc, but I see this problem for quite some time, didn't post it before because my pc was not preinstalled for a long time and it could be something else.

BitComet 1.28 64bit

100Mbit/s LAN with peers in my own country, 20Mbit/s international

Router TP-Link WR340G with DMZ to my internal ip

Windows 7 64bit, windows firewall and microsoft security essentials

[The UnUsual Suspect]

If you have sufficient quantity of unused ram memory, try increasing the size of your disc cache. This is the exact reason it exists.

However, in large torrents, there is a high degree of probability that the disc cache cannot cache enough data to stop the need for new disc reads. Also, any member using extremely large disc cache sizes should make sure they have installed the 64bit version of bitcomet (which of course you already have). It's able to handle much larger memory access.

[CyberTod]

Yes I have enough ram, I will increase the cache. What number do you suggest for the cache ? I have 8gb ram and currently using around 2gb, my swap is disabled. Currently I am seeding a 7gb file with around 500kb/s upload speed to 15-20 peers.

Update : I increased the cache to 60-500mb (auto in given range). The reads dropped to 2-10mb/s and the actual disk reads to 1.7/s down from 15.1/s

Edited August 5, 2011 by CyberTod (see edit history)

[The UnUsual Suspect]

Good, then the cache is doing it's job. The only way to get the reads down close to zero would be to have your disc cache equal or larger then the sum of all tasks, but even then, the data won't be cached until it's needed, so you'll still get random disc reads.

BitComet x64 is coded to allow upto 16gB of disc cache. Since you have paging disabled, you need to keep more ram available then a system normally would, but if I were you, and the ram was unused anyway, I'd up the limit some more.

BitComet 32bit users should beware that any 32bit program can become unstable if it's total memory usage approaches 2gB (combined program usage and disc cache). Use care when setting large cache sizes on 32bit bitcomet.

[CyberTod]

Thank you. Yes it is much better now. I made it 600mb now, will try some more to see what is best for me. But I guess the more the better while still leaving enough for other things.