[hpsdr] Computer Latency

[Don Kay - KI6FOM]

My system also has a Geforce 8800GT and was behaving like your second 
system (low latency mostly but occasionally jumping up to almost a 
millisecond). I finally got rid of the periodic high latency spikes by 
removing the nvidia drivers and running with the standard svga drivers. 
After I isolated the problem to the nvidia drivers I did a simple web 
search and found lots of complaints about nvidia driver latency on the 
pro-audio sites. Apparently this is a known issue in those circles. I 
had to put my system back the way it was since I need the 3D 
acceleration for some other apps, but have resolved to buy a radeon card 
as soon as possible.

It would be an interesting experiment if you were to swap the video 
cards in your system 2 and 3.

73
-don ki6fom


lstoskopf at cox.net wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> Sitting here with three computers set up for HPSDR.  Decided to run the DPC Latency Checker on each just for fun:
>
> HP pavillion D4100Y with Pentium D 2.8 GHz:  30-50uS.
>
> Put together:  Core2 Duo E8500 3.16 GHz  GeForce 8800GT graphics:  wierd, jumps from 2uS to 700uS sort of alternating.  No other programs running or processes seen on Task Manager.  Both have Semantic 360 security suites.
>
> Put together i7:  Core 7 920 2.67 GHz with ATI Radeon HB4770 and Node 32 antivirus:  7 uS steady.
>
> All work well as would be expected.  Of course filled with the latest appropriate memory for the time or purchase.
>
>
> OT:  Went to Radio Shack today for some batteries.  The have some oft their premium RCA connectors  (AF/Video) on clearance and you can get the fancy gold plated, etc. ones for $2-$4 depending on length and how many wires in the cable.  Won't make the rig run better, but sure are purdy!
>
> N0UU
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