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| Thread ID: 30354 | 2003-02-17 04:03:00 | Ext. HDD | Pete O'Neil (250) | Press F1 |
| Post ID | Timestamp | Content | User | ||
| 122012 | 2003-02-17 04:03:00 | i was looking at buying an external hdd case that uses USB 2.0 as the interface. The website claims it has transfer speeds of 480mbits/sec but wouldn't it max out at 100mbits/sec as that is the speed of the HDD interface?? | Pete O'Neil (250) | ||
| 122013 | 2003-02-17 04:17:00 | USB 2.0 is indeed specified to have a transfer rate of 480 Mbit/sec. It can probably do that if the computer isn't too busy, and the cables are perfect, and the software is correct (:D), and there aren't too many devices on the chain, and ... But you are right: once the data have reached the box, it will be limited by the disk speed. So it will hurry/wait/hurry/wait ... What you have seen on the web site is advertising. It doesn't have to be the whole truth. :D |
Graham L (2) | ||
| 122014 | 2003-02-17 04:57:00 | USB 2.0 is 480 Mb/s which = 60MB/s, while ata100 is 100MB/s. however the actuall sustained read speed is proberly only around 50-60MB/s. don't get your bits mixed up with your bytes :) |
tweak'e (174) | ||
| 122015 | 2003-02-17 11:10:00 | Okay hmm good idea about not mixing up the 'b'its with the 'B'ytes although in tests i have seen in various magazines i have not yet seen any yet that can manage speeds of this. Much more typical speeds being in the 10-20Megabyte range per second. Not that I know everything that out there as indeed i dont but this claim seems rather high. I would suggest a program such as SiSoft Sandra to see what speeds are achievable on the device, or get details from the manufacturer or perhaps review sites. Also i would like to note from some of my previous HDD research i did on the net while the 'full speed' may not be reachable because of the HDD's limitations i also found an article stating that Interfaces can also take quite a bit of the so called speed for communications or signalling each other as to what to do. |
Captive (3159) | ||
| 122016 | 2003-02-18 03:11:00 | ah, i knew there had to be something i was missing. Thanx for clearing that up, speed wise it seems like on of these might be worth considering for backups and easy data transfer. | Pete O'Neil (250) | ||
| 122017 | 2003-02-19 02:31:00 | APC has a short review of a serial ATA drive usiing two different interfaces, comparing it with an ATA133 one. The fastest transfer on any of them was 99 MB/s for a buffered read on ATA133. !GB file write was 10 , 14, 34 MB/s for the three drives. Random reads scored 4 MB/s, 6 and 6. Random writes 8, 9 and 11 MB/s. Looks as if the USB would have a bit of spare time to make the tea... :D | Graham L (2) | ||
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