I would like to buy a Usb Transcend JetFlash 700 (with read70Mb/s,write 20Mb/s SPEED), but i only have 2.0 ports.
-So will those ports slow down my usb flash drive.
-and if they will slow down my usb how much will it.
-Is it beter form me tu buy a fast usb 2.0 flash drive?
I would say it's very likely it would run much slower on a USB 2.0 connection.. USB 2.0 is rated at 480Mbit/sec or 60MB/sec, but I've never seen it over around 30MB/sec real world even when transferring one large file from a USB 2.0 7200rpm hd. If you were getting the absolute max speed based on the definitions I guess you would only lose 10MB/sec on the write speed, but to me that seems very doubtful.
Yes, it will slow down on USB 2.0 ports. I would guess it would operate at 30 Mb/s read and 10-15 MB/s write. It is important to note that this would be in ideal situations. This occurs when copying a few large files such as movies. When copying many small files the transfer speed will be significantly less.
Its not necessarily better or worse. If you think that at some point (while you are still using the flash drive) you will upgrade to a computer with USB 3.0 then it might be worth it to purchase it. If you don't think that will happen then it doesn't really matter whether you buy a USB 2.0 or 3.0 flash drive. Just go with the cheapest one of your desired capacity from a reputable manufacturer.