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followup - USB 2 & 3 speeds ... 

By: monkeytrots in POPE IV | Recommend this post (1)
Wed, 12 Jul 17 5:57 AM | 60 view(s)
Boardmark this board | POPES NEW and Improved Real Board 		Msg. 28968 of 47202
(This msg. is a reply to 28967 by monkeytrots)
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I stand corrected - USB 2 could theoretically achieve and maintain the needed 23 MBytes/sec speed calculated by the 'Forensicator'.

USB 3- even the poorest of them (100MBs) could do it.

The now-aging USB 2.0 standard can theoretically transfer data at a very high 480 megabits per second (mbps), or 60 megabytes per second (MBps). That’s impressive, but not as much as the newer USB 3.0, which can handle up to 5gbps (640MBps)—over ten times as fast as the 2.0 maximum.

Why is it that the current crop of USB 3.0 flash drives don't deliver full USB 3.0 speed? Most of them max out—according to manufacturer specifications—at 100MBps (800mbps) or less. In a casual search, I only found one, the Mushkin Enhanced Ventura Plus, that advertised a read speed of 200MBps (1.6gbps). That’s still less than half USB 3.0's maximum.

http://www.pcworld.com/article/2360306/usb-3-0-speed-real-and-imagined.html


Many USB-2 external HARD DISKS could achieve the 23 MB/sec rate ....

USB 2 uses 1 millisecond frames, and in High Speed (480 Mb/s) mode they are divided into 8 micro-frames. The maximum size of bulk packets (used by USB mass storage devices) is 512 bytes. According to this very informative document the theoretical maximum is 13 packets per microframe. So the theoretical maximum speed of a USB 2 drive is:

1000 * 8 * 512 * 13 = 53248000 ~= 53 MB/s

This other document from Cypress http://www.cypress.com/file/139866/download says near the end that they actually acheive 43 MB/s.

In practice the limit will usually be the flash itself.

Edit: This information is actually also in the USB 2 spec.

https://superuser.com/questions/317217/whats-the-maximum-typical-speed-possible-with-a-usb2-0-drive

The external USB-Hard Drives usually exceed the performance of OTS 'thumb drives'.


UPDATE: Apparently 'bacbone speeds' are now available in both 100Gbit/sec and 10Gbit/sec speeds. What the actual achievable throughput for a single-or multiport end-to-end connection - a tangled web. Only the mega-ISP's have direct backbone service.




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Re: waaaaaaaaa babies/liers... BOMBSHELL: New Report Shows Guccifer 2.0-DNC Files Were Copied Locallyâ�&iuml
By: monkeytrots in POPE IV
Wed, 12 Jul 17 5:50 AM 		Msg. 28967 of 47202

True, Zim - over INTERNAL direct connect giga-bit ethernet. USB 1&2 were slower (much) than most disk-to-disk (dma access) - Firewire could handle it, as could certain other 'external' devices connecting to the dma channel. As you point out - the gigabit connects would handily beat the USB downloads. Tape drives (and some optical drives) could/and do handle dma transfer rates - but NOT those that connect via USB.

Very few 'internal servers' have gigabit INTERNET (not ethernet) connections ... especially at both ends - and especially going to Roosha.

I don't see the DNC having that type of Internet backbone available to them. Google,FB,etc. - yes - in the aggregate. From a single server - and a single connection - I would highly doubt it.

Perhaps DE could weigh in on this - more up his professional alley I would think.

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