09/02/2009, 04:19 AM
A few people pointed out IDM in my FDM review, so I decided to check it out.
First up, I must say the initial interface is rather disappointing.
Here's my criticisms:
Overall, to be quite honest, I see little justification in going for this app. FDM offers more features, works better internally, and is free.
First up, I must say the initial interface is rather disappointing.
Here's my criticisms:
- The "Time left" column seems to be totally wrong here on my test download (connection speed is stable, but the time is stuck at "3 seconds" when it's quite obvious that it's going to take around 20 seconds to complete)
Note, this test download doesn't support resuming (I made it that way). For files that support resuming (Accept-Ranges header), it seems to work properly.
- The status window is very basic - pretty much just displays the download progress and shows nothing about headers sent etc. Can't be docked to the main window either. It does show how much each connection has downloaded at least, I guess.
- The "Add URL" dialog is pretty retarded - why does it come up with 2 dialogs? Can't it just use the 2nd one for all the info?
- Even on the 2nd Add dialog, there's very little options. No options for referrer, number of portions to split, can't manually specify mirrors/alternative URLs, no proxy selection etc. Very little control over the download at an individual file level.
- The speed is a lie. IDM claims that I'm downloading at ~57-58KB/sec on my 512Kbps connection. Certainly within the maximum limit, but I know for sure I can't get such a fast sustained transfer speed, as every single other app maxes out at ~52-53KB/sec. Just to verify that IDM doesn't have some magical component in it, I test downloaded a 2.2MB (exactly 2,332,126 bytes) file using IDM and Flashget, and timed each. Both took slightly longer than 46 seconds (around 46.5s), though IDM claimed speeds of 57KB/sec whereas FlashGet claimed 52KB/sec, so it's quite obvious that the real transfer speeds are very similar. Doing a calculation, you get around 49.5KB/sec, but then, that includes overhead such as initiating the download etc, so the Flashget speed seems more accurate (plus my other applications display the same thing). Used 2 connections for both IDM and FlashGet.
- IDM doesn't preallocate space for the download on the destination drive - instead, it saves to a temp directory, and even then, doesn't do any preallocation. This is bad for a number of reasons:
1) Obvious overhead of moving the file after the download completes (this won't occur if you have everything on the same drive). But even on the same drive, because it doesn't preallocate, it's forced to save every connection to a separate file, which means it has to do a concatenation (rewrite the entire file) after the download completes.
2) Preallocation assures that there won't be an issue of running out of free space
3) Probably insignificant, but fragmentation issues.
- IDM uses the AppData folder, thus more difficult to make a portable version.
- No multi-proxy support. Furthermore, no SOCKS proxy support (FDM also suffers from lack of SOCKS proxy support - forgot to mention it in previous thread)
- Surprisingly, despite being the most basic compared with FlashGet and FDM, it uses the most RAM, though it doesn't really use that much to be of any real significance.
- You're limited to 16 connections. You could argue that there's little point in having more, but I can point out a number of specific cases where it does help. Either case, why put the artificial limit there? What's worse is that you're forced to use a number which is a power of 2. At least IDM isn't silly enough to go overboard with connections if you ask it to use 16 on a small file.
Overall, to be quite honest, I see little justification in going for this app. FDM offers more features, works better internally, and is free.