# GPU Benchmark & Speed **URL:** \ **Category:** Skydel Discussion\ **Created:** [September 30, 2020, 11:11am UTC](https://learn.safran-navigation-timing.com/t/gpu-benchmark-speed/58 "2020-09-30T11:11:09Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![rburke](https://yyz2.discourse-cdn.com/flex030/user_avatar/learn.safran-navigation-timing.com/rburke/32/29_2.png) [@rburke](https://learn.safran-navigation-timing.com/u/rburke)\ **Post date:** [September 30, 2020, 11:11am UTC](https://learn.safran-navigation-timing.com/t/gpu-benchmark-speed/58/1 "2020-09-30T11:11:09Z")
Could you provide a bit more information on testing the speed of the GPU? I have configured a radio for GPS L1 with 24 satellites and getting marginal performance on the benchmark screen. I am also curious how the score is calculated which is now at 1.0. ![Picture2](https://canada1.discourse-cdn.com/flex030/uploads/orolia/original/1X/e396a49f4019f89f84285cdef57fde63f0b3f4a5.png) ---
**Author:** ![julien.edmond](https://yyz2.discourse-cdn.com/flex030/user_avatar/learn.safran-navigation-timing.com/julien.edmond/32/32_2.png) [@julien.edmond](https://learn.safran-navigation-timing.com/u/julien.edmond)\ **Post date:** [September 30, 2020, 1:12pm UTC](https://learn.safran-navigation-timing.com/t/gpu-benchmark-speed/58/2 "2020-09-30T13:12:31Z")
Hi Robert! That score is the answer to the question “How many seconds of simulation can my GPU compute in one second?”, so the higher the better. Here you are at exactly 1.0, it means you are too close to the edge with your current hardware and the smallest interruption from another process might prevent the simulation to stay real time. The amount of work a GPU is doing in a Skydel simulation is a product of the number of visible satellites, the number of signals associated to those satellites and the output’s sampling rate. So you could reduce these parameters to find a configuration more suited to the hardware you are currently using. Hope this helps! ---
**Author:** ![stephane.hamel](https://yyz2.discourse-cdn.com/flex030/user_avatar/learn.safran-navigation-timing.com/stephane.hamel/32/26_2.png) [@stephane.hamel](https://learn.safran-navigation-timing.com/u/stephane.hamel)\ **Post date:** [September 30, 2020, 2:05pm UTC](https://learn.safran-navigation-timing.com/t/gpu-benchmark-speed/58/3 "2020-09-30T14:05:34Z")
Hi Robert, Looking at the screenshot, I can see that you have selected GPS L1CA, L1C, L1P and L5 as well as Galileo E5 AltBOC (E5a & E5b). The number of satellites simply indicate the typical number of visible satellites for your test. The simulator always simulates the entire constellation, but will modulate the signals only when they are visible from the receiver point of view. So at any given time in your scenario, 14 GPS satellite is enough as long as you stay on Earth. For space simulation, you can have more visible satellites and may want to increase that number to reflect the reality in space. So in this benchmark, **you are actually simulating 56 GPS signals and 20 Galileo signals simultaneously for a total of 76 signals**. Not bad for a modest GPU such as the GTX 1650. You can easily double the performance using a better GPU and if 150 signals is not enough, you can add more GPUs in a computer. ---
**Author:** ![rburke](https://yyz2.discourse-cdn.com/flex030/user_avatar/learn.safran-navigation-timing.com/rburke/32/29_2.png) [@rburke](https://learn.safran-navigation-timing.com/u/rburke)\ **Post date:** [October 10, 2020, 10:52am UTC](https://learn.safran-navigation-timing.com/t/gpu-benchmark-speed/58/4 "2020-10-10T10:52:51Z")
Thanks Julien. What would be some of the specific effects on the test if I were to run with a score below 1.0? ---
**Author:** ![julien.edmond](https://yyz2.discourse-cdn.com/flex030/user_avatar/learn.safran-navigation-timing.com/julien.edmond/32/32_2.png) [@julien.edmond](https://learn.safran-navigation-timing.com/u/julien.edmond)\ **Post date:** [October 13, 2020, 1:47pm UTC](https://learn.safran-navigation-timing.com/t/gpu-benchmark-speed/58/5 "2020-10-13T13:47:50Z")
Running a scenario that has a score below 1.0 has almost no chance of keeping up with the real time. As soon as the simulation is too late, the simulation will stop with an Underrun or Underflow error, which means that the SDR did not have anything to transmit in time. ---
**Author:** ![rburke](https://yyz2.discourse-cdn.com/flex030/user_avatar/learn.safran-navigation-timing.com/rburke/32/29_2.png) [@rburke](https://learn.safran-navigation-timing.com/u/rburke)\ **Post date:** [October 15, 2020, 12:10am UTC](https://learn.safran-navigation-timing.com/t/gpu-benchmark-speed/58/6 "2020-10-15T00:10:43Z")
Thanks so much for the info Julien.