Slow download speeds
If you experience slow downloads, it could be for many reasons. However,
they can be different when you experience slow download speed from certain
user(s) or when you get slow speeds downloading from every peer. Please try
to download from or get filelist of several (at least 10) users before you go on.
Note that this faq does NOT cover the case when your downloads won't start at all.
Slow downloads from certain user(s)
Reasons connections with some users may be too slow:
-
The upload bandwidth of the peer you are downloading from is maxed out. Don't pay attention to
the value of the Connection column in the user
list: it is subjective and often not an accurate representation of the user's actual speed.
-
The peer you are downloading from is too far from you (maybe on another continent) and too many
hops
are necessary to connect you to your peer.
It is also possible that either your ISP or the other user's provider has limited overseas
bandwitdh available.
You can view your peer's country in
Transfers area (provided the
Guess user country from IP setting is enabled).
- The person who you are downloading from is using a bandwidth
limiter. There are two types of limiting: client based or using a third-party
program.
- Clients with bandwidth limiting capability often have set download
and upload speed ratios in place to avoid abuse. (ex. if the
upload speed limit is set below 6 KiB/s, then the client will restrict
the client download speed to a 2:1 ratio). This varies from
client to client and obviously not all support upload limiting.
This type of speed limiting only
restricts the uploading of files, including user lists. It
does not limit chat, private messages, or searches. From version 0.760
DC++ also has internal file transfer limiting capability. If enabled, DC++ shows
the upload limiting rate in the
Connection coloumn
of a hub's user list. Other (older) clients may show this value in
L: or B: part of the DC++ tag.
- Users could also be using a third-party program to limit the
speed of traffic. This type of speed limiting is absolute; it
will limit the speed of all traffic by the user, which can include file
transfers, searches, chat, and private messages. This type
of application never enforce a download speed:upload speed ratio, it
may be more prone to abuse.
So for particularly slow transfers (1 KiB/s or slower) from a certain user,
abusive upload limiting may be to blame.
- The person who you are downloading from suffers from one or more
constant speed problem described in the next section.
Solution: try to find more sources for your downloads:
-
To find more sources for your download, right-click it from the
Download Queue or from the
Transfers area and select the
Search for alternates command. A corresponding
Search window will open,
the "Slots" column of the result list of which can be leveraged to find users with available
bandwidth.
-
More sources for queued files can be discovered and automatically added if you enable
Automatically Match Queue for Search Hits
in Queue settings.
-
Automatic discovery for additional sources is also possible if you enable
Automatically Search for Alternative Download Locations
in Queue settings. Note that some hubs have
predefined minimum search interval rules so enabling this function may
result no hits for manual searches in these hubs.
-
To minimize the download time make sure you have checked
Enable segmented downloads in
Advanced settings. With segmented downloads enabled
you are able to download the pieces of a file from several sources at the same time.
Slow downloads from every user
Slow downloads within DC++ may be caused by the following:
- Bandwidth limiting is enabled for downloads.
Make sure the limiter is disabled or set to a high enough value.
- Your Internet connection is shared with others on your LAN and they are using up all the
available bandwidth. Tell them to knock it off. =)
Also your connection speed to the gateway or router on your LAN can be slower than the available speed
from your ISP.
It could be for reasons like week signal strength on a wireless connection,
broken/old network devices, etc... Try to do a file transfer test within your local
network to be sure that it's fast enough.
- Your ISP may be limiting your P2P traffic via some method of
packet shaping. Call up the ISP and inquire if they do anything
with P2P traffic. You can try to connect to ADC hubs and test your downloads there.
As ADC is a newer and more efficient DC protocol it can be still unknown to your ISP's
throttling system. If the ISP does
throttle you, then there is nothing much that can be done to increase the
speeds. This is also common at Universities and at the workplace,
and is the topic of another FAQ.
- You haven't set up your third party firewall or internet monitor
software correctly. Some of these security applications may treat p2p transfer as a
DDoS flood attempt and tries to defend your computer from it.
Try to disable or even uninstall these applications temporarily and test your downloads again.
If it helps refer the application's documentation how to make exception rules for DC++.
If you have a router its also possible that it has some anti-DDoS or flood protection
feature and it may enabled by default. Check the router's documentation or configuration page
for a possible option of this kind.
- You need to optimize your operating system for your current
connection speed. First, close all P2P applications. Next run the DSLReports
TweakTest. Once you have optimized it, then run a speed test at
DSLReports
SpeedTest Page or at the nice looking
SpeedTest.Net page
(select a test site closest to your location for
accurate results). This will give you a good idea what your
maximum download and upload speeds are. If you're getting within
10% of your connection speed, that's the best you can get! If you
are having trouble with your broadband
connection, and it relates to packet loss, excessive latency, or
Internet or ISP
congestion, running the Line Quality Test
may help find the cause (requires logon, free signup).
Your Internet connection is DSL, cable, or satellite one
with an asymmetrical connection speed, such as 768/128 Kib/s or
3.0 Mib/s / 256 Kib/s. On such connections, if you upload near the speed of
your upload limit (16 KiB/s in the case of the 768/128 connection), it
may affect the speeds of your downloads, no matter how much larger
your download connection is. If this is happening, you can use the
built-in transfer limiting function
to set the maximum upload rate value slightly lower than
your available upload speed (eg. to 15 or 14 KiB/s in the case above).
If you aren't allowed to use upload limiting you can also experiment with changing the
size of Socket Write Buffer in Experts Only
panel of DC++ settings. It defaults to 8 KiB and you can try to change it to a smaller
value. You should specify the value in bytes and you may have to try several values
to test what size suits your connection best. Note that you should restart DC++ to
changes take effect.
- The "QoS Packet Scheduler" is enabled
in your Windows so you are not able to use some reserved bandwidth for download. Follow
this guide to disable QoS in Windows 7 or 8.
Some routers also have QoS capabilities, but it shouldn't be enabled by default. Please consult your router's manual for more
information.
- Your computer is infected with malicious software which altered the low level network
settings of your operating system. This is common when your Windows become infected with spy/adware.
Even they are disinfected, their destructive modifications usually still remain. You can
follow the official guided help from Microsoft how to restore these settings
in Windows 7 and 8.x.
If you're running Windows 10 you can try
this guide
to fix network settings.