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DS development > dswifi download speed

#150757 - csk - Tue Feb 12, 2008 3:56 am

Hi, I'm new to this forum, but have been playing around with the DS for a while. :)

I tried searching, but didn't really find an answer to my question.

I'm having the following problem: the maximum transfer rate I can achieve with dswifi (CVS), is 100 KiB/sec (FTP download). My target would be something like 140-150 KiB/sec. DSLinux can achieve 130 KiB/sec, so I believe it should be possible with dswifi as well.

So my questions is: how do I maximize the download speed using dswifi?

I'm using recv() to receive data in a loop (also tried to receive data from a timer interrupt, but the speed was the same). I tried 10240 bytes, and 65536 bytes, and 512 K as buffer sizes, but the speed was the same.

I'd appreciate any kind of help.

Thanks in advance!

#150761 - josath - Tue Feb 12, 2008 4:44 am

dslinux uses a different TCP/IP stack than dswifi. sgstair himself has mentioned the best he's gotten was 120KB/sec using a modified dswifi (not the one everyone uses). So if you are getting 100KB/sec, i think that's pretty good.

#150762 - csk - Tue Feb 12, 2008 5:01 am

Thanks for the quick reply. Could you point me to the post where sgstair mentions the 120 KB/sec result? Actually it might be enough for me. Also, did he mention what the bottleneck was?

I've also seen some posts of DSFTP users achieving 140 KB/s (IIRC). What's the reason for that? Maybe their method of measuring the speed was a bit inaccurate?

Thanks!

#150824 - csk - Wed Feb 13, 2008 3:11 am

I'm still trying to figure out how to get a bit more bandwidth with dswifi, but meanwhile, another question came up.

If I'm using two Nintendo DS Lites, and simultaneously downloading using both of them from a FTP server, then the effective bandwidth on one DS halves, ie. if I get 90 KB/sec using one DS at a time, then I get around 45 KB/sec using two DSs (45 KB/sec on each of them).

They are both connected to the same access point, same FTP server. My PC and the access point are connected by 100 Mbit Ethernet, so that's not a problem. I don't think the FTP server limits the download speed (I'm using vsftpd on Linux, default configuration).

Did anyone experience the same slowdown? Is there a workaround?

Thanks!