# LimeSDR / LimeSDR mini USB 2.0 backwards compatibility
**URL:** https://discourse.myriadrf.org/t/limesdr-limesdr-mini-usb-2-0-backwards-compatibility/2990
**Category:** General Discussion
**Created:** [4 July 2018 17:38 UTC](https://discourse.myriadrf.org/t/limesdr-limesdr-mini-usb-2-0-backwards-compatibility/2990 "2018-07-04T17:38:19Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@sqrt2](https://discourse.myriadrf.org/u/sqrt2)
#### Post date: [4 July 2018 17:38 UTC](https://discourse.myriadrf.org/t/limesdr-limesdr-mini-usb-2-0-backwards-compatibility/2990/1 "2018-07-04T17:38:19Z")
Hello, I am planning to buy a LimeSDR, but I am not quite sure how well it is going to work on my old laptop:
- only USB 2.0 ports
- Intel Core i5 CPU (integrated Intel HD Graphics) with OpenCL 2.0 support
I read that the bandwidth of USB 2.0 is compared to USB 3.0 significantly smaller, limiting the transmission of samples. Does anyone have experience with a LimeSDR connected to an USB 2.0 port? What performance is to be expected?
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### Author:  [@M0GLO](https://discourse.myriadrf.org/u/M0GLO)
#### Post date: [5 July 2018 06:55 UTC](https://discourse.myriadrf.org/t/limesdr-limesdr-mini-usb-2-0-backwards-compatibility/2990/2 "2018-07-05T06:55:20Z")
5MHz - 10MHz bandwidth is what I found on my old system with USB2, it would be unreliable much higher than that.
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### Author:  [@yindra](https://discourse.myriadrf.org/u/yindra)
#### Post date: [9 July 2018 15:38 UTC](https://discourse.myriadrf.org/t/limesdr-limesdr-mini-usb-2-0-backwards-compatibility/2990/3 "2018-07-09T15:38:52Z")
different version of limesuite install different version of firmware. I found that firmware version 18.06 is not able to communicate over USB 2.0, except to perform self-test.
> [@LimeSDR-USB Transmit with gr-limesdr](https://discourse.myriadrf.org/t/limesdr-usb-transmit-with-gr-limesdr/2929/8):
>
> Here is the Quick Test result: Here is the RX test signal: Here is the TX carrier signal: [20180620\_txCarrierSignal] Here is the TX test signal: [20180620\_txTestSignal] I got the same results when I loaded the 18.06 firmware with Modules-\>Programming (it then downloaded the 18.06 firmware and installed it) with LimeSuiteGUI\_20180613\_1cb1723.exe
I found that the limesdr\_toolbox software can fill the transmit fifo, but the LimeSDR-USB never reads data from the transmit fifo. The limesdr\_toolbox software gets stuck once the lime::StreamChannel’s fifo is full.
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### Author:  [@sqrt2](https://discourse.myriadrf.org/u/sqrt2)
#### Post date: [25 August 2018 18:29 UTC](https://discourse.myriadrf.org/t/limesdr-limesdr-mini-usb-2-0-backwards-compatibility/2990/4 "2018-08-25T18:29:04Z")
I just tested mine on ubuntu 18.04 and it performs just as well as you state. Thank you!