Thread: q: PC USB mode faster than acess via N900 xterm?
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reinob is offline reinob
2013-02-13 , 09:26
Posts: 1,808 | Thanked: 4,272 times | Joined on Feb 2011 @ Germany
#6
Originally Posted by bozoid View Post
eMMC is accessed directly by N900 while via PC, there is the USB "bottleneck"...
The question is: what is faster? USB or the MMC interface?

I guess it depends on lots of factors, but probably the interface speed is about the same. So it comes down to which computer (N900 vs PC) can handle the data transfer faster. The N900 is not only slow, but can get very busy while caching (+ swapping), while the PC can shuffle bits around with essentially no overhead.

data might need to go all the way up into PC CPU/mem buffers and all the way back down into N900. Unless there is some mechanism in N900 eMMC
Of course. The N900 can't do magic. If a partition is USB-mounted on a host, it is entirely controlled by the host, meaning that even if you copy from MMC to MMC the data will go "up" to the PC and then back "down" to the MMC.

which takes away the need for that to happen (, where data frm eMMC goes into an N900 local buffer and then go back onto eMMC for writes, thus bypassing USB and PC altogether). But if such a mechanism exists, wldnt it be used within the kernel in N900? (would mean that N900 eMMC IO could be much faster!). Hmmm. Curious curious...
kh
Nope
 

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