Increase the IQ Rate of USRP (NI-USRP 1.1 Driver)

[ErikL]

Optimizing USRP Performance in Windows

We’ve achieved 25MS/s using a Dell core i7-PC, Quadcore, 16GB of RAM and an integrated Intel 1 Gigibit Network Interface

1. Optimizing Overall Performance
   • Use a desktop computer with an Intel network adapter.  The network card seems to be capable of higher rates than their laptop equivalents.
   • Select the High performance power plan in Windows.  (Control Panel > Hardware and Sound > Power Options)

 

• Use the manufacturer’s driver, rather than the default Windows driver. And optimize options for performance.

          i. Increase receive buffer size

          ii.      Increase Transmit Buffer size

          iii.      Enable Receive Side Scaling if available

          iv.      Disable power saving options such as “Energy Efficient Ethernet”

Note that some overflows are due to the ‘wake-up time’ required to begin using Ethernet after it has been starved by another process in the operating system.

Registry Key required for NI-USRP 1.2 (not required for NI-USRP 1.1)

For improving Transmit, enable ‘FastSendDatagramThreshold’.  A reboot may be required for it to take effect.

• Start Registry Editor (Regedt32.exe).
• Locate the following key in the registry:

HKLM\System\CurrentControlSet\Services\Afd\Parameters

• On the Edit menu, click Add Value, and then add the following registry value:
• Value Name: FastSendDatagramThreshold
• Data Type: REG_DWORD
• Value: 2048 (decimal)
• Quit Registry Editor.

[ORN]

Hi Erik

I have done this optimizing, but still it disconnect at 6,25/12.5 or 25 MSPS if i try do network-access through another network-adapter (browsing  or disk access) , (PC = Dell-XPS , Core i7-2600 3.4 GHz Quadcore, 8GB RAM,Win7pro-64 , USRP = N210 , Network adapter = Intel PRO/1000PT PCI-Express )

Anny other sugestions?

[ErikL]

We have seen much better performance on desktop pc's than with laptops.

[ORN]

Hi Erik
it's a Desktop(6.2 in windows experience index),
With you set-up try do some network access while streaming from the USRP(at 12.5 / 25 MSPS)  , read a network disk or web access ,or try play som youtube video.
we have seen the same issue on several computers , even a computer with 2 X CPU (2 X 4 core Xenon E5620 @2.4GHz) and a dedicated PCI-Express lan card.

i think this is a windows driver/buffer problem, when using USRP with Linux we don't see this problems

You mentioned NI-USRP 1.2 driver , when would this be released?

[manuel.vonhelden@noffz.co]

Hi Erik and all others,
do you have any experience, why the performance on laptops is less than on desktop PCs?
We have high performance laptops, where we are getting trouble with data streaming. With a similar PC we do not get these problems.
If it is helpful for you, we can provide more details.

THX and best regards,
Manuel

[USBarnes]

Manuel,

Could you give us more information about the chipset on your laptops?

[manuel.vonhelden@noffz.co]

Hi Robert, for example we tried a Lenovo T520 with the following spec: Core i7-2670QM :: 6MB L3 Cache + 512KB L2 Chipset: Mobile Intel QM67 / Sandy Bridge Graphics: 1GB nVidia Quadro NVS 4200M Optimus Rergarding the chip of the LAN module, I will check and let you know. Best regards, Manuel

[manuel.vonhelden@noffz.co]

in addition to my last post, we are using the folling Network Adapter: Intel 82579LM Gigabit Network Connection Best regards, Manuel

[USBarnes]

Manuel,

Aside from the suggestions Erik made, I don't think there are too many steps left. Something else to try might be disabling the firewall. Maybe there is some packet filtering caused by the firewall that is decreasing performance. After speaking with a colleague on this, he had the following list of things to monitor/check:

• Use Wireshark to check that the UDP packets are being received correctly (not generating an ICMP flood as a result of some network stack weirdness)
• Use Process Explorer to see what is taking up CPU time - make sure it's the SDR (USRP) app and nothing else (e.g. firewall), and minimally system DPCs/kernel (Deferred Procedure Calls)
  
• Check in the Windows Resource Monitor that the CPU is running at max frequency.
• Use Window Performance Monitor, add CPU/core freq/state counters to plot the C-states of the cores/throttling/NIC & network buffer throughput/etc (there are lots of handy counters for this) and see how it looks while the USRP is running.
• Laptops also will perform throttling outside the control of the OS (e.g. if it gets too hot), and this should be reflected in those counters

My colleague also mentioned that certain NICs might perform better. He uses a Thunderbolt GigE adapter, which contains a Broadcom NIC (Tigon3), and says that it works flawlessly. I'd like to point out that I am merely passing this information along to this forum, and by no means am I (or my colleague) claiming that buying a Thunderbolt GigE adapter is going to correct any of these issues. These are merely suggestions that might be worth looking into. In any case, I hope this helps!