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Ubuntu Download Speeds Beat Windows XP's
narramissic writes "Doing a download speed test of his Time Warner cable connection, James Gaskin discovered something odd, something that he is quick to note isn't a rigorous benchmarked lab test. The discovery: His Ubuntu machine 'returned a rating from the Bandwidth.com test of 22-25mbps over several tests' while the same test done from a Windows XP PC returned a rating of 12-14mbps. The two computers used in the test are 'almost identical: both off-lease Compaq small form factor D515s, part of the very popular corporate desktop D500 family. Both have Pentium 4 processors running at 2GHz. The Ubuntu machine has 768MB of RAM, while the XP box has only 512MB of RAM. Both run Firefox 3 as their browser.' Gaskin's question: Can a little extra RAM make that much difference in Internet download speeds or does Ubuntu handles networking that much faster than Windows XP?"
I'd guess it's some kind of TCP/IP optimization (the default size of packets, etc). It's set to one thing on Ubuntu, and another on Windows (probably for some historical reason or due to some old buggy driver).
If that's not it, I'd bet pretty high it's a bad driver in Windows.
It's quite likely that either Windows or Ubuntu is intrinsically faster for some reason, but I doubt the difference based on the way the networking stack is designed is anywhere near 10%, let alone 50% for a link this fast. On 10 gigE maybe, but not on a simple cable modem.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
The poster said 'i think ubuntu downloads stuff faster than xp but I'm not sure... the RAM is different.'
So how did this make it to slashdot. Its not like anyone but the poster has the identical hardware to run the tests properly.
@poster: If the machines are so 'identical' then swap the memory and run the tests again.
You can't test two different machines with different cases and compare the results, that's not how the scientific process works. Both machines need to be tested against the same cases - then and only then will you be able to appropriately tell if the software made a difference.
Anyhow, back on the subject, some of WinXP's default networking parameters are a bit conservative when it comes to high-bandwidth links that don't have LAN-like latency (particularly the TCP Receive Window/RWIN); a good but short description of this can be found at DSL Reports. So I wouldn't be absolutely shocked if once he corrects his methodology, he still gets similar results, although in general I find RWIN tweaking to be bollocks compared to the few people that swear it works. Vista and later OSs include self-adjusting network stacks that compensate for this and then some (Microsoft is rather proud of their sustained bandwidth over very high latency links), so I wouldn't lose any sleep over it.
True, but considering both computers should easily be able to saturate a 100baseT connection, shouldn't both configurations be able to saturate a 22Mbps link?
This is different than the guy complaining that the computers can't fill a gigabit ethernet connection with a scp transfer while music is playing.
The http that the speed test should be using doesn't have any encryption, shouldn't be using gzip, and it shouldn't be saved to hard drive.
If I have nothing to hide, don't search me
It's the TCP implementations, and probably the TCP window size limits. Windows could turn in the same numbers if properly tuned.
You want to read this article for all the in-depth details: http://www.psc.edu/networking/projects/tcptune/
Windows has a default set many years ago, and never updated. Most of the Free Unix variants update every release, and some new variants even have fancy auto-scaling code. Any time you want to get over 10Mbps/second across any real latency with a SINGLE TCP stream you probably need to do some tuning, for some OS's the limit is much lower.
ISP's run into this all the time. An uninformed admin buys a GigE in LA and NY, pops up an FTP server and wonders why he can only get a few megabits a second across the "crappy network". A few settings later and behold, the same hardware can saturate a full gigabit.
Note, don't just go set your values really high, there are performance (memory used) tradeoffs....
Actually I can see it all the time. My Ubuntu laptop's (IBM T42) WiFi is about 50% faster that the same configured Windows machine of my wife. We're talking about SAME hardware. I don't really know if it's drivers, or something else.
Performance on LAN is more similar, difference is about 10-20% max, but with this kind of hardware it heavily depends on HDD to write data and Windows is crap at this - it's swapping - god knows why!!!
"an experienced, industrious, ambitious, and often, quite often, picturesque liar" - Mark Twain
BS. XP runs fine on 0.5GB ram. Hell, when it came out, what was the norm for a new machine? 128MB? 256?
You're thinking of Vista.
That's a myth.
Clarification about the use of QoS in end computers that are running Windows XP
As in Windows 2000, programs can take advantage of QoS through the QoS APIs in Windows XP. One hundred percent of the network bandwidth is available to be shared by all programs unless a program specifically requests priority bandwidth. This "reserved" bandwidth is still available to other programs unless the requesting program is sending data. By default, programs can reserve up to an aggregate bandwidth of 20 percent of the underlying link speed on each interface on an end computer. If the program that reserved the bandwidth is not sending sufficient data to use it, the unused part of the reserved bandwidth is available for other data flows on the same host.
http://support.microsoft.com/kb/316666
A new low in slashdot history. Can't remember a worse headline and article in recent times, can anyone else?
This article is just one big WTF. Is slashdot that desperate for traffic?
By these standards your nut article will indeed make a headline soon.
And why did my submission not get posted, yet:
My windows PC with a 27 inch screen runs at 1600x1200 resolution, my ubuntu on a 15 incher only 1024x768. Are windows graphics drivers better than the linux kernel?"
I'm a sysadmin at Ohio State, and a number of old firewalls (really old OpenBSD version plus badly-written pf scripts, still in use!) have the same problem. The connection through them breaks when any computer using TCP window scaling over "2" (Windows Vista, Linux) tries to connect to a server behind the firewall. So, yes, window scaling will either make the connection blazing fast, or will block certain users if a bad router/firewall is on the route between the computer and a server.
I'd mod you up, but I feel compelled to reply ... since I'm amazed nobody has mentioned this.
I just signed up for Time Warner 'net myself, and when the dude was checking the signal he mentioned something about how there's a 25Mbit "boost" that people get at random. I didn't get a chance to ask many questions about it, but he said that it wasn't just an ISP-level cache ... you're actually given 25Mbit of bandwidth for a breif amount of time. That could very well be what we're seeing here, as the numbers seem to align.
Who doesn't like free music?
Here's my totally unscientific test from my home office. Vista 32bit vs. Ubuntu 32bit. Done on a dual-boot Thinkpad T61 laptop, 2.0ghz 2gb RAM. Nowhere close to running out of memory, only app running was the browser (plus the normal tray stuff).
I did five tests with each OS/browser and averaged them out, doing the bandwidth.com test.
Figures in kbps. ISP is Comcast cable.
Windows Vista Chrome 1.0.154.43
Down: 18276.6 (avg) / 21522 (max)
Up: 1866.8 (avg) / 1898 (max)
Windows Vista Firefox 3.05
Down: 17357 (avg) / 23820 (max)
Up: 1044.6 (avg) / 1067 (max)
Ubuntu 8.10 (Intrepid) Firefox 3.05
Down: 15451.6 (avg) / 21742 (max)
Up: 2035.6 (avg) / 2151 (max)
The averages differed wildly but I think network traffic can easily account for this. Since the maximums were all nearly the same I think they're all about the same.
What it doesn't account for is the upload speed, which were very consistent throughout this silly test.
Vista firefox = dismal
Vista chrome = much faster
Ubuntu firefox = even faster
>I wish apple would sell a powerbook with a real right-click.
And I wish other laptops had the "two finger" right click and the two-finger scroll.
-fb Everything not expressly forbidden is now mandatory.
Modern Linux kernel 2.6.17 and later has TCP auto tuning, so it can better adapt to the network and saturate it. http://www.psc.edu/networking/projects/tcptune/#Linux Windows XP default TCP window size is too small and needs registry tuning for it to be optimized high speed broadband connections. Just google for WinXP TCP tuning. Or try comparing with Vista as it has better TCP/IP stack.
It's in reference to a Gentoo Stage1 install where the system is compiled mostly from scratch. It looks like it is only recommended for l337 developers now as that FAQ mentions that end-users shouldn't use it.
~ I am logged on, therefore I am.
They are talking about the Ancilliary Function Driver that is used for Windows sockets. By setting HKLM\CurrentControlSet\Services\AFD\DefaultSendWindow to 0x7800 allows them to set this to 480KB of data before flow control kicks in. Great if your hardware can handle it, not so great if you have crappy hardware. I believe that if you have > 32MB of RAM that the default is 8KB of data gets received before flow control throttles the connection.
Probably will work OK if your NIC can handle it and you have enough memory. And of course if you have high enough bandwidth :-)
XML is like violence. If it doesn't solve the problem, use more.