Am Mon, 15 May 2017 22:14:48 +0100
schrieb lee <l...@yagibdah.de>:

> Kai Krakow <hurikha...@gmail.com> writes:
> 
> > Am Sun, 14 May 2017 01:28:55 +0100
> > schrieb lee <l...@yagibdah.de>:
> >  
> >> Kai Krakow <hurikha...@gmail.com> writes:
> >>   
>  [...]  
>  [...]  
> >>  [...]    
>  [...]  
> >> 
> >> Wow, you must be living in some sort of paradise.  Here, internet
> >> is more like being cut off from the rest of the world.
> >> 
> >> But then, there's a manufacturer that makes incredibly slow USB
> >> sticks which I won't buy anymore ...  
> >
> > Okay, it really depends. I shouldn't say "most"... ;-)  
> 
> Intenso --- pretty cheap, but awfully slow; however, it does
> work. Better don't buy anything they make unless your time is entirely
> worthless to you.
> 
> > I compared my really crappy (but most reliable yet) old USB stick
> > to my internet connection. My USB stick doesn't do 48 MByte/s, more
> > like 5-10. And don't even ask when writing data.  
> 
> 5--10MB/s?  How do you get that much?

For reading? It can work, tho it will eventually drop to 2 MB/s after a
short time. For writing: It drops well below 1 MB/s after a short burst.

> > Even my rusty hard disk (read: not SSD) has a hard time writing
> > away a big download with constantly high download rate.  
> 
> It must be really old then, about 20 years.

No, it's just that other IO is also ongoing and filesystem internals
have some write overheads and involve head movement which easily limits
the drive from its theoretical ideal rate of 120-150 MB/s. Short
bursts: No problem. Long running writes are more like 50-70 MB/s, which
is pretty near the download rate.

It's also what I see in gigabit networks: Copy speed could be somewhere
between 100 and 120 MB/s, but the local drive seems to easily limit
this to 70-80 MB/s.

My current setup allows constant writing of around 270-280 MB/s
according to:

# dd bs=1M if=/dev/urandom of=test.dat
13128171520 bytes (13 GB, 12 GiB) copied, 48,0887 s, 273 MB/s

So it's not that bad... ;-)

But dd also runs at 100% CPU during that time, so I guess the write
rate could be even higher. I see combined rate of up to 500 MB/s
sometimes tho I'm not sure if this is actual transfer rate or just
queued IO rate. Also, it is pretty near the SATA bus saturation. I'm
not sure if my chipset would deliver this rate per SATA connection or
as a combined rate.


> > But I guess that a good internet connection should be at least 50
> > MBit these days.  
> 
> I'd say 100, but see above.  The advantage is that you have sufficient
> bandwidth to do several things at the same time.  I've never seen fast
> internet.

My provider easily delivers such rates, given the remote side is fast
enough. Most downloads a saturated at around 15-20 MB/s. Only few
servers can deliver more. Probably not only a limit of the servers, but
the peer network connections.


> > And most USB sticks are really crappy at writing. That also counts
> > when you do not transfer the file via network. Of course, most DSL
> > connections have crappy upload speed, too. Only lately, Telekom
> > offers 40 MBit upload connections in Germany.  
> 
> They offer 384kbit/s downstream and deliver 365.  It's almost
> symmetrical, yet almost unusable.

Sounds crappy... No alternative providers there? Problem is almost
always a combination of multiple factors: A long running cable limiting
DSL to a lower physical bandwidth, and usually a too limited traffic
concentrator in that area: You should see very different transfer rates
at different times of the day.


> They also offer 50Mbit and deliver between 2 and 12, and upstream is
> awfully low.  Tell them you could pay for 16 instead of 50 because you
> don't get even that much, and they will tell you that you would get
> even less than you do now.  That is unacceptable.

Yes... They would downgrade you to less performing DSL technology then.
It's all fine for them because you only pay for "up to" that bandwidth.


> And try to get a static IP so you could really use your connection ...

No problems so far, at least for business plans.


> > I'm currently on a 400/25 MBit link and can saturate the link only
> > with proper servers like the Steam network which can deliver 48
> > MByte/s.  
> 
> You must be sitting in a data center and be very lucky to have that.

Cable network... In a smallish city.

Next involvement is announced to be 1 GBit in around 2018-2019...
Something, that's already almost standard in other European countries.
Well... "standard" in terms of availability... Not actual usage. I
think the prices will be pretty high. But that's okay: If you need it,
you should be willing to pay that. It won't help to have such bandwidth
without the provider being able to effort the needed infrastructure.
It's already over-provisioned too much as you already found out.


-- 
Regards,
Kai

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